path: root/epan/dissectors/packet-synphasor.c

/* packet-synphasor.c
 * Dissector for IEEE C37.118 synchrophasor frames.
 *
 * Copyright 2008, Jens Steinhauser <jens.steinhauser@omicron.at>
 * Copyright 2019, Dwayne Rich <dwayne_rich@selinc.com>
 * Copyright 2020, Dmitriy Eliseev <eliseev_d@ntcees.ru>
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"

#include <math.h>

#include <epan/packet.h>
#include <epan/crc16-tvb.h>
#include <epan/expert.h>
#include <epan/proto_data.h>
#include <epan/tfs.h>
#include <epan/unit_strings.h>

#include <wsutil/array.h>
#include "packet-tcp.h"

#include <wsutil/utf8_entities.h>

#define PNAME "IEEE C37.118 Synchrophasor Protocol"
#define PSNAME "SYNCHROPHASOR"
#define PFNAME "synphasor"

/* forward references */
void proto_register_synphasor(void);
void proto_reg_handoff_synphasor(void);

/* global variables */

static int proto_synphasor;

/* user preferences */
#define SYNPHASOR_TCP_PORT  4712 /* Not IANA registered */
#define SYNPHASOR_UDP_PORT  4713 /* Not IANA registered */

/* Config 1 & 2 frames have channel names that are all 16 bytes long */
/* Config 3 frame channel names have a variable length with a max of 255 characters */
#define CHNAM_LEN 16
#define MAX_NAME_LEN 255
#define G_PMU_ID_LEN 16

/* the ett... variables hold the state (open/close) of the treeview in the GUI */
static int ett_synphasor; /* root element for this protocol */
/* used in the common header */
static int ett_frtype;
static int ett_timequal;
/* used for config frames */
static int ett_conf;
static int ett_conf_station;
static int ett_conf_format;
static int ett_conf_phnam;
static int ett_conf_annam;
static int ett_conf_dgnam;
static int ett_conf_phconv;
static int ett_conf_phlist;
static int ett_conf_phflags;
static int ett_conf_phmod_flags;
static int ett_conf_ph_user_flags;
static int ett_conf_anconv;
static int ett_conf_anlist;
static int ett_conf_dgmask;
static int ett_conf_chnam;
static int ett_conf_wgs84;
/* used for data frames */
static int ett_data;
static int ett_data_block;
static int ett_data_stat;
static int ett_data_phasors;
static int ett_data_analog;
static int ett_data_digital;
/* used for command frames */
static int ett_command;
static int ett_status_word_mask;

/* handles to the header fields hf[] in proto_register_synphasor() */
static int hf_sync;
static int hf_sync_frtype;
static int hf_sync_version;
static int hf_station_name_len;
static int hf_station_name;
static int hf_idcode_stream_source;
static int hf_idcode_data_source;
static int hf_g_pmu_id;
static int hf_frsize;
static int hf_soc;
static int hf_timeqal_lsdir;
static int hf_timeqal_lsocc;
static int hf_timeqal_lspend;
static int hf_timeqal_timequalindic;
static int hf_fracsec_raw;
static int hf_fracsec_ms;
static int hf_cont_idx;
static int hf_conf_timebase;
static int hf_conf_numpmu;
static int hf_conf_formatb3;
static int hf_conf_formatb2;
static int hf_conf_formatb1;
static int hf_conf_formatb0;
static int hf_conf_chnam_len;
static int hf_conf_chnam;
static int hf_conf_phasor_mod_b15;
static int hf_conf_phasor_mod_b10;
static int hf_conf_phasor_mod_b09;
static int hf_conf_phasor_mod_b08;
static int hf_conf_phasor_mod_b07;
static int hf_conf_phasor_mod_b06;
static int hf_conf_phasor_mod_b05;
static int hf_conf_phasor_mod_b04;
static int hf_conf_phasor_mod_b03;
static int hf_conf_phasor_mod_b02;
static int hf_conf_phasor_mod_b01;
static int hf_conf_phasor_type_b03;
static int hf_conf_phasor_type_b02to00;
static int hf_conf_phasor_user_data;
static int hf_conf_phasor_scale_factor;
static int hf_conf_phasor_angle_offset;
static int hf_conf_analog_scale_factor;
static int hf_conf_analog_offset;
static int hf_conf_pmu_lat;
static int hf_conf_pmu_lon;
static int hf_conf_pmu_elev;
static int hf_conf_pmu_lat_unknown;
static int hf_conf_pmu_lon_unknown;
static int hf_conf_pmu_elev_unknown;
static int hf_conf_svc_class;
static int hf_conf_window;
static int hf_conf_grp_dly;
static int hf_conf_fnom;
static int hf_conf_cfgcnt;
static int hf_data_statb15to14;
static int hf_data_statb13;
static int hf_data_statb12;
static int hf_data_statb11;
static int hf_data_statb10;
static int hf_data_statb09;
static int hf_data_statb08to06;
static int hf_data_statb05to04;
static int hf_data_statb03to00;
static int hf_command;
static int hf_cfg_frame_num;

/* Generated from convert_proto_tree_add_text.pl */
static int hf_synphasor_data;
static int hf_synphasor_checksum;
static int hf_synphasor_checksum_status;
static int hf_synphasor_num_phasors;
static int hf_synphasor_num_analog_values;
static int hf_synphasor_num_digital_status_words;
static int hf_synphasor_rate_of_transmission;
static int hf_synphasor_phasor;
static int hf_synphasor_actual_frequency_value;
static int hf_synphasor_rate_change_frequency;
static int hf_synphasor_frequency_deviation_from_nominal;
static int hf_synphasor_analog_value;
static int hf_synphasor_digital_status_word;
static int hf_synphasor_conversion_factor;
static int hf_synphasor_factor_for_analog_value;
static int hf_synphasor_channel_name;
static int hf_synphasor_extended_frame_data;
static int hf_synphasor_unknown_data;
static int hf_synphasor_status_word_mask_normal_state;
static int hf_synphasor_status_word_mask_valid_bits;

static expert_field ei_synphasor_extended_frame_data;
static expert_field ei_synphasor_checksum;
static expert_field ei_synphasor_data_error;
static expert_field ei_synphasor_pmu_not_sync;

static dissector_handle_t synphasor_udp_handle;
static dissector_handle_t synphasor_tcp_handle;

/* the different frame types for this protocol */
enum FrameType {
	DATA = 0,
	HEADER,
	CFG1,
	CFG2,
	CMD,
	CFG3
};

/* Structures to save CFG frame content. */

/* type to indicate the format for (D)FREQ/PHASORS/ANALOG in data frame	 */
typedef enum {	integer,	/* 16 bit signed integer */
	       floating_point	/* single precision floating point */
} data_format;

typedef enum { rect, polar } phasor_notation_e;

typedef enum { V, A } unit_e;

/* holds the information required to dissect a single phasor */
typedef struct {
	char	name[MAX_NAME_LEN + 1];
	unit_e	unit;
	uint32_t	conv;			/* cfg-2 conversion factor in 10^-5 scale */
	float	conv_cfg3;		/* cfg-3 conversion scale factor */
	float	angle_offset_cfg3;	/* cfg-3 angle offset */
} phasor_info;

/* holds the information for an analog value */
typedef struct {
	char	name[MAX_NAME_LEN + 1];
	uint32_t	conv;		/* cfg-2 conversion scale factor, user defined scaling (so it's pretty useless) */
	float	conv_cfg3;	/* cfg-3 conversion scale factor */
	float	offset_cfg3;	/* cfg-3 conversion offset */
} analog_info;

/* holds information required to dissect a single PMU block in a data frame */
typedef struct {
	uint16_t		   id;			/* (Data Source ID) identifies source of block     */
	char		   name[MAX_NAME_LEN + 1]; /* holds STN			  */
	uint8_t		   cfg_frame_type;	/* Config Frame Type (1,2,3,...)  */
	data_format	   format_fr;		/* data format of FREQ and DFREQ  */
	data_format	   format_ph;		/* data format of PHASORS	  */
	data_format	   format_an;		/* data format of ANALOG	  */
	phasor_notation_e  phasor_notation;	/* format of the phasors	  */
	unsigned		   fnom;		/* nominal line frequency	  */
	unsigned		   num_dg;		/* number of digital status words */
	wmem_array_t	  *phasors;		/* array of phasor_infos	  */
	wmem_array_t	  *analogs;		/* array of analog_infos	  */
} config_block;

/* holds the id the configuration comes from an and
 * an array of config_block members */
typedef struct {
	uint32_t		fnum;		/* frame number */
	uint16_t		id;		/* (Stream Source ID) identifies source of stream */
	uint32_t		time_base;	/* Time base - resolution of FRACSEC time stamp. */
	wmem_array_t	*config_blocks; /* Contains a config_block struct for
				      * every PMU included in the config frame */
} config_frame;

/* strings for type bits in SYNC */
static const value_string typenames[] = {
	{ 0, "Data Frame"		},
	{ 1, "Header Frame"		},
	{ 2, "Configuration Frame 1"	},
	{ 3, "Configuration Frame 2"	},
	{ 4, "Command Frame"		},
	{ 5, "Configuration Frame 3"	},
	{ 0, NULL			}
};

/* strings for version bits in SYNC */
static const value_string versionnames[] = {
	{ 1, "Defined in IEEE Std C37.118-2005"	},
	{ 2, "Added in IEEE Std C37.118.2-2011"	},
	{ 0, NULL				}
};

/* strings for the time quality flags in FRACSEC */
static const true_false_string leapseconddir = {
	"Add",
	"Delete"
};
static const value_string timequalcodes[] = {
	{ 0xF, "Clock failure, time not reliable"	},
	{ 0xB, "Clock unlocked, time within 10 s"	},
	{ 0xA, "Clock unlocked, time within 1 s"	},
	{ 0x9, "Clock unlocked, time within 10^-1 s"	},
	{ 0x8, "Clock unlocked, time within 10^-2 s"	},
	{ 0x7, "Clock unlocked, time within 10^-3 s"	},
	{ 0x6, "Clock unlocked, time within 10^-4 s"	},
	{ 0x5, "Clock unlocked, time within 10^-5 s"	},
	{ 0x4, "Clock unlocked, time within 10^-6 s"	},
	{ 0x3, "Clock unlocked, time within 10^-7 s"	},
	{ 0x2, "Clock unlocked, time within 10^-8 s"	},
	{ 0x1, "Clock unlocked, time within 10^-9 s"	},
	{ 0x0, "Normal operation, clock locked"		},
	{  0 , NULL					}
};

/* strings for flags in the FORMAT word of a configuration frame */
static const true_false_string conf_formatb123names = {
	"32-bit IEEE floating point",
	"16-bit integer"
};
static const true_false_string conf_formatb0names = {
	"polar",
	"rectangular"
};

/* strings to decode ANUNIT in configuration frame */
static const range_string conf_anconvnames[] = {
	{  0,	0, "single point-on-wave"	},
	{  1,	1, "rms of analog input"	},
	{  2,	2, "peak of input"		},
	{  3,	4, "undefined"			},
	{  5,  64, "reserved"			},
	{ 65, 255, "user defined"		},
	{  0,	0, NULL				}
};

/* strings for the FNOM field */
static const true_false_string conf_fnomnames = {
	"50Hz",
	"60Hz"
};

static const true_false_string conf_phasor_mod_b15 = {
	"Modification applied, type not here defined",
	"None"
};

static const true_false_string conf_phasor_mod_b10 = {
	"Pseudo-phasor value (combined from other phasors)",
	"None"
};

static const true_false_string conf_phasor_mod_b09 = {
	"Phasor phase adjusted for rotation",
	"None"
};

static const true_false_string conf_phasor_mod_b08 = {
	"Phasor phase adjusted for calibration",
	"None"
};

static const true_false_string conf_phasor_mod_b07 = {
	"Phasor magnitude adjusted for calibration",
	"None"
};

static const true_false_string conf_phasor_mod_b06 = {
	"Filtered without changing sampling",
	"None"
};

static const true_false_string conf_phasor_mod_b05 = {
	"Down sampled with non-FIR filter",
	"None"
};

static const true_false_string conf_phasor_mod_b04 = {
	"Down sampled with FIR filter",
	"None"
};

static const true_false_string conf_phasor_mod_b03 = {
	"Down sampled by reselection",
	"None"
};

static const true_false_string conf_phasor_mod_b02 = {
	"Up sampled with extrapolation",
	"None"
};

static const true_false_string conf_phasor_mod_b01 = {
	"Up sampled with interpolation",
	"None"
};

static const value_string conf_phasor_type[] = {
	{ 0, "Voltage, Zero sequence"		},
	{ 1, "Voltage, Positive sequence"	},
	{ 2, "Voltage, Negative sequence"	},
	{ 3, "Voltage, Reserved"		},
	{ 4, "Voltage, Phase A"			},
	{ 5, "Voltage, Phase B"			},
	{ 6, "Voltage, Phase C"			},
	{ 7, "Voltage, Reserved"		},
	{ 8, "Current, Zero sequence"		},
	{ 9, "Current, Positive sequence"	},
	{ 10, "Current, Negative sequence"	},
	{ 11, "Current, Reserved"		},
	{ 12, "Current, Phase A"		},
	{ 13, "Current, Phase B"		},
	{ 14, "Current, Phase C"		},
	{ 15, "Current, Reserved"		},
	{  0, NULL				}
};

static const true_false_string conf_phasor_type_b03 = {
	"Current",
	"Voltage"
};

static const value_string conf_phasor_type_b02to00[] = {
	{ 0, "Zero sequence"	},
	{ 1, "Positive sequence"},
	{ 2, "Negative sequence"},
	{ 3, "Reserved"		},
	{ 4, "Phase A"		},
	{ 5, "Phase B"		},
	{ 6, "Phase C"		},
	{ 7, "Reserved"		},
	{ 0, NULL		}
};

static const true_false_string conf_phasor_user_defined = {
	"Flags set",
	"No flags set"
};

/* strings for flags in the STAT word of a data frame */
static const value_string data_statb15to14names[] = {
	{ 0, "Good measurement data, no errors"							},
	{ 1, "PMU error, no information about data"						},
	{ 2, "PMU in test mode or absent data tags have been inserted (do not use values)"	},
	{ 3, "PMU error (do not use values)"							},
	{ 0, NULL										}
};
static const true_false_string data_statb13names = {
	"Synchronization lost",
	"Clock is synchronized"
};
static const true_false_string data_statb12names = {
	"By arrival",
	"By timestamp"
};
static const true_false_string data_statb11names = {
	"Trigger detected",
	"No trigger"
};
static const true_false_string data_statb10names = {
	"Within 1 minute",
	"No"
};
static const true_false_string data_statb09names = {
	"Data modified by a post-processing device",
	"Data not modified"
};
static const value_string      data_statb08to06names[] = {
	{ 0, "Not used (indicates code from previous version of profile)"	},
	{ 1, "Estimated maximum time error < 100 ns" 				},
	{ 2, "Estimated maximum time error < 1 " UTF8_MICRO_SIGN "s"		},
	{ 3, "Estimated maximum time error < 10 " UTF8_MICRO_SIGN "s"		},
	{ 4, "Estimated maximum time error < 100 " UTF8_MICRO_SIGN "s"		},
	{ 5, "Estimated maximum time error < 1 ms"				},
	{ 6, "Estimated maximum time error < 10 ms"				},
	{ 7, "Estimated maximum time error > 10 ms or time error unknown"	},
	{ 0, NULL								}
};
static const value_string      data_statb05to04names[] = {
	{ 0, "Locked or unlocked less than 10 s"},
	{ 1, "Unlocked for 10-100 s"		},
	{ 2, "Unlocked for 100-1000 s"		},
	{ 3, "Unlocked for over 1000 s"		},
	{ 0, NULL				}
};
static const value_string      data_statb03to00names[] = {
	{ 0x0, "Manual"				},
	{ 0x1, "Magnitude low"			},
	{ 0x2, "Magnitude high"			},
	{ 0x3, "Phase-angel diff"		},
	{ 0x4, "Frequency high or low"		},
	{ 0x5, "df/dt high"			},
	{ 0x6, "Reserved"			},
	{ 0x7, "Digital"			},
	{ 0x8, "User defined"			},
	{ 0x9, "User defined"			},
	{ 0xA, "User defined"			},
	{ 0xB, "User defined"			},
	{ 0xC, "User defined"			},
	{ 0xD, "User defined"			},
	{ 0xE, "User defined"			},
	{ 0xF, "User defined"			},
	{   0, NULL				}
};

/* strings to decode the commands (CMD Field) according Table 15, p.26
*  0000 0000 0000 0001  -  Turn off transmission of data frames
*  0000 0000 0000 0010  -  Turn on transmission of data frames
*  0000 0000 0000 0011  -  Send HDR frame
*  0000 0000 0000 0100  -  Send CFG-1 frame.
*  0000 0000 0000 0101  -  Send CFG-2 frame.
*  0000 0000 0000 0110  -  Send CFG-3 frame (optional command).
*  0000 0000 0000 1000  -  Extended frame.
*  0000 0000 xxxx xxxx  -  All undesignated codes reserved.
*  0000 yyyy xxxx xxxx  -  All codes where yyyy ≠ 0 available for user designation.
*  zzzz xxxx xxxx xxxx  -  All codes where zzzz ≠ 0 reserved.
*/
static const range_string command_names[] = {
	{  0x0000, 0x0000, "reserved codes"		},
	{  0x0001, 0x0001, "data transmission off"	},
	{  0x0002, 0x0002, "data transmission on"	},
	{  0x0003, 0x0003, "send HDR frame"		},
	{  0x0004, 0x0004, "send CFG-1 frame"		},
	{  0x0005, 0x0005, "send CFG-2 frame"		},
	{  0x0006, 0x0006, "send CFG-3 frame"		},
	{  0x0007, 0x0007, "reserved codes"		},
	{  0x0008, 0x0008, "extended frame"		},
	{  0x0009, 0x00FF, "reserved codes"		},
	{  0x0100, 0x0FFF, "user designation"		},
	{  0x1000, 0xFFFF, "reserved codes"		},
	{  0x0000, 0x0000, NULL				}
};


/******************************************************************************
* functions
******************************************************************************/

/* read in the size length for names found in config 3 frames
	0 - no name
	1-255 - length of name
*/
static uint8_t get_name_length(tvbuff_t *tvb, int offset)
{
	uint8_t name_length;

	/* read the size of the name */
	name_length = tvb_get_uint8(tvb, offset);

	return name_length;
}

/* Checks the CRC of a synchrophasor frame, 'tvb' has to include the whole
 * frame, including CRC, the calculated CRC is returned in '*computedcrc'.
 */
static bool check_crc(tvbuff_t *tvb, uint16_t *computedcrc)
{
	uint16_t crc;
	unsigned	len = tvb_get_ntohs(tvb, 2);

	crc = tvb_get_ntohs(tvb, len - 2);
	*computedcrc = crc16_x25_ccitt_tvb(tvb, len - 2);

	if (crc == *computedcrc)
		return true;

	return false;
}

/* Dissects a configuration frame (only the most important stuff, tries
 * to be fast, does no GUI stuff) and returns a pointer to a config_frame
 * struct that contains all the information from the frame needed to
 * dissect a DATA frame.
 *
 * use 'config_frame_free()' to free the config_frame again
 */
static config_frame *config_frame_fast(tvbuff_t *tvb)
{
	uint16_t		num_pmu;
	int		offset;
	config_frame	*frame;

	/* get a new frame and initialize it */
	frame = wmem_new(wmem_file_scope(), config_frame);

	frame->config_blocks = wmem_array_new(wmem_file_scope(), sizeof(config_block));

	// Start with Stream Source ID - identifies source of stream
	offset = 4;
	frame->id = tvb_get_ntohs(tvb, offset);

	/* Skip to time base for FRACSEC */
	offset += 11; // high 8 bits reserved for flags, so +1 byte
	frame->time_base = tvb_get_uint24(tvb, offset,ENC_BIG_ENDIAN);

	/* Next number of PMU blocks */
	offset += 3;
	num_pmu = tvb_get_ntohs(tvb, offset);

	// Start of repeating blocks
	offset += 2;

	while (num_pmu) {
		uint16_t	     format_flags;
		int	     num_ph,
			     num_an,
			     num_dg;
		int	     i,
			     phunit,
			     anunit,
			     fnom;
		config_block block;

		/* initialize the block */
		block.phasors = wmem_array_new(wmem_file_scope(), sizeof(phasor_info));
		block.analogs = wmem_array_new(wmem_file_scope(), sizeof(analog_info));
		/* copy the station name from the tvb to block, and add NULL byte */
		tvb_memcpy(tvb, block.name, offset, CHNAM_LEN); offset += CHNAM_LEN;
		block.name[CHNAM_LEN] = '\0';
		block.cfg_frame_type = 2;
		block.id = tvb_get_ntohs(tvb, offset); offset += 2;

		format_flags	      = tvb_get_ntohs(tvb, offset); offset += 2;
		block.format_fr	      = (format_flags & 0x0008) ? floating_point : integer;
		block.format_an	      = (format_flags & 0x0004) ? floating_point : integer;
		block.format_ph	      = (format_flags & 0x0002) ? floating_point : integer;
		block.phasor_notation = (format_flags & 0x0001) ? polar		 : rect;

		num_ph = tvb_get_ntohs(tvb, offset); offset += 2;
		num_an = tvb_get_ntohs(tvb, offset); offset += 2;
		num_dg = tvb_get_ntohs(tvb, offset); offset += 2;
		block.num_dg = num_dg;

		/* the offset of the PHUNIT, ANUNIT, and FNOM blocks */
		phunit = offset + (num_ph + num_an + num_dg * CHNAM_LEN) * CHNAM_LEN;
		anunit = phunit + num_ph * 4;
		fnom   = anunit + num_an * 4 + num_dg * 4;

		/* read num_ph phasor names and conversion factors */
		for (i = 0; i != num_ph; i++) {
			phasor_info  pi;
			uint32_t	     conv;

			/* copy the phasor name from the tvb, and add NULL byte */
			tvb_memcpy(tvb, pi.name, offset, CHNAM_LEN); offset += CHNAM_LEN;
			pi.name[CHNAM_LEN] = '\0';

			conv = tvb_get_ntohl(tvb, phunit + 4 * i);
			pi.unit = conv & 0xFF000000 ? A : V;
			pi.conv = conv & 0x00FFFFFF;
			pi.conv_cfg3 = 1;
			pi.angle_offset_cfg3 = 0;

			wmem_array_append_one(block.phasors, pi);
		}

		/* read num_an analog value names and conversion factors */
		for (i = 0; i != num_an; i++) {
			analog_info ai;
			uint32_t	    conv;

			/* copy the phasor name from the tvb, and add NULL byte */
			tvb_memcpy(tvb, ai.name, offset, CHNAM_LEN); offset += CHNAM_LEN;
			ai.name[CHNAM_LEN] = '\0';

			conv = tvb_get_ntohl(tvb, anunit + 4 * i);
			ai.conv = conv;
			ai.conv_cfg3 = 1;
			ai.offset_cfg3 = 0;

			wmem_array_append_one(block.analogs, ai);
		}

		/* the names for the bits in the digital status words aren't saved,
		   there is no space to display them in the GUI anyway */

		/* save FNOM */
		block.fnom = tvb_get_ntohs(tvb, fnom) & 0x0001 ? 50 : 60;
		offset = fnom + 2;

		/* skip CFGCNT */
		offset += 2;

		wmem_array_append_one(frame->config_blocks, block);
		num_pmu--;
	}

	return frame;
} /* config_frame_fast() */

/* Dissects a configuration 3 frame (only the most important stuff, tries
 * to be fast, does no GUI stuff) and returns a pointer to a config_frame
 * struct that contains all the information from the frame needed to
 * dissect a DATA frame.
 *
 * use 'config_frame_free()' to free the config_frame again
 */
static config_frame * config_3_frame_fast(tvbuff_t *tvb)
{
	uint16_t	      num_pmu;
	int	      offset;
	config_frame *frame;
	phasor_info  *pi = NULL;
	analog_info  *ai = NULL;
	bool          frame_not_fragmented;

	/* get a new frame and initialize it */
	frame = wmem_new(wmem_file_scope(), config_frame);

	frame->config_blocks = wmem_array_new(wmem_file_scope(), sizeof(config_block));

	// Start with Stream Source ID - identifies source of stream
	offset = 4;
	frame->id = tvb_get_ntohs(tvb, offset);

	/* Skip to CONT_IDX -- Fragmented Frames not supported at this time */
	offset += 10;
	frame_not_fragmented = tvb_get_uint16(tvb, offset, ENC_BIG_ENDIAN) == 0;

	/* Skip to time base for FRACSEC */
	offset += 3; // high 8 bits reserved for flags, so +1 byte
	frame->time_base = tvb_get_uint24(tvb, offset,ENC_BIG_ENDIAN);

	/* Skip to number of PMU blocks */
	offset += 3;
	num_pmu = tvb_get_ntohs(tvb, offset);

	/* start of repeating blocks */
	offset += 2;
	while ((num_pmu) && (frame_not_fragmented)) {
		uint16_t	     format_flags;
		int	     num_ph,
			     num_an,
			     num_dg;
		int	     i;
		uint8_t	     name_length;
		config_block block;

		/* initialize the block */
		block.phasors = wmem_array_new(wmem_file_scope(), sizeof(phasor_info));
		block.analogs = wmem_array_new(wmem_file_scope(), sizeof(analog_info));

		/* copy the station name from the tvb to block, and add NULL byte */
		/* first byte is name size */
		name_length = get_name_length(tvb, offset);
		offset += 1;

		tvb_memcpy(tvb, block.name, offset, name_length);
		offset += name_length;

		block.name[name_length] = '\0';
		block.cfg_frame_type = 3;

		/* Block ID and Global PMU ID */
		block.id = tvb_get_ntohs(tvb, offset);
		offset += 2;

		/* skip over Global PMU ID */
		offset += G_PMU_ID_LEN;

		format_flags	      = tvb_get_ntohs(tvb, offset);
		offset += 2;

		block.format_fr	      = (format_flags & 0x0008) ? floating_point : integer;
		block.format_an	      = (format_flags & 0x0004) ? floating_point : integer;
		block.format_ph	      = (format_flags & 0x0002) ? floating_point : integer;
		block.phasor_notation = (format_flags & 0x0001) ? polar		 : rect;

		num_ph = tvb_get_ntohs(tvb, offset);
		offset += 2;

		num_an = tvb_get_ntohs(tvb, offset);
		offset += 2;

		num_dg = tvb_get_ntohs(tvb, offset);
		offset += 2;
		block.num_dg = num_dg;

		/* grab phasor names */
		if (num_ph > 0)
		{
			pi = (phasor_info *)wmem_alloc(wmem_file_scope(), sizeof(phasor_info)*num_ph);

			for (i = 0; i != num_ph; i++) {
				/* copy the phasor name from the tvb, and add NULL byte */
				name_length = get_name_length(tvb, offset);
				offset += 1;

				tvb_memcpy(tvb, pi[i].name, offset, name_length);
				offset += name_length;

				pi[i].name[name_length] = '\0';
			}
		}

		/* grab analog names */
		if (num_an > 0)
		{
			ai = (analog_info *)wmem_alloc(wmem_file_scope(), sizeof(analog_info)*num_an);

			for (i = 0; i != num_an; i++) {
				/* copy the phasor name from the tvb, and add NULL byte */
				name_length = get_name_length(tvb, offset);
				offset += 1;

				tvb_memcpy(tvb, ai[i].name, offset, name_length);
				offset += name_length;

				ai[i].name[name_length] = '\0';
			}
		}

		/* skip digital names */
		if (num_dg > 0)
		{
			for (i = 0; i != num_dg * 16; i++) {
				name_length = get_name_length(tvb, offset);
				offset += name_length + 1;
			}
		}

		/* get phasor conversion factors */
		if (num_ph > 0)
		{
			for (i = 0; i != num_ph; i++) {
				uint32_t phasor_unit;

				/* get unit */
				phasor_unit = tvb_get_ntohl(tvb, offset);
				pi[i].unit = phasor_unit & 0x00000800 ? A : V;
				pi[i].conv = 1;
				pi[i].conv_cfg3 = tvb_get_ntohieee_float(tvb, offset + 4);
				pi[i].angle_offset_cfg3 = tvb_get_ntohieee_float(tvb, offset + 8);

				wmem_array_append_one(block.phasors, pi[i]);

				offset += 12;
			}
		}

		/* get analog conversion factors */
		if (num_an > 0)
		{
			for (i = 0; i != num_an; i++) {
				ai[i].conv = 1;
				ai[i].conv_cfg3 = tvb_get_ntohieee_float(tvb, offset);
				ai[i].offset_cfg3 = tvb_get_ntohieee_float(tvb, offset + 4);

				wmem_array_append_one(block.analogs, ai[i]);

				offset += 8;
			}
		}

		/* skip digital masks */
		if (num_dg > 0)
		{
			for (i = 0; i != num_dg; i++) {
				offset += 4;
			}
		}

		/* Skip to FNOM */
		offset += 21;

		/* save FNOM */
		block.fnom = tvb_get_ntohs(tvb, offset) & 0x0001 ? 50 : 60;
		offset += 2;

		/* skip CFGCNT - offset ready for next PMU */
		offset += 2;

		wmem_array_append_one(frame->config_blocks, block);
		num_pmu--;
	}

	return frame;
} /* config_3_frame_fast() */

/* Dissects the common header of frames.
 *
 * Returns the framesize, in contrast to most
 * other helper functions that return the offset.
 */
static int dissect_header(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo)
{
	proto_tree *temp_tree;
	proto_item *temp_item;
	config_frame *conf;

	int	offset = 0;
	uint16_t	framesize;

	conf = (config_frame *)p_get_proto_data(wmem_file_scope(), pinfo, proto_synphasor, 0);

	/* SYNC and flags */
	temp_item = proto_tree_add_item(tree, hf_sync, tvb, offset, 2, ENC_BIG_ENDIAN);
	temp_tree = proto_item_add_subtree(temp_item, ett_frtype);
	proto_tree_add_item(temp_tree, hf_sync_frtype,	tvb, offset, 2, ENC_BIG_ENDIAN);
	proto_tree_add_item(temp_tree, hf_sync_version, tvb, offset, 2, ENC_BIG_ENDIAN);
	offset += 2;

	/* FRAMESIZE */
	proto_tree_add_item(tree, hf_frsize, tvb, offset, 2, ENC_BIG_ENDIAN);
	framesize = tvb_get_ntohs(tvb, offset); offset += 2;

	/* IDCODE */
	proto_tree_add_item(tree, hf_idcode_stream_source, tvb, offset, 2, ENC_BIG_ENDIAN);
	offset += 2;

	/* SOC */
	proto_tree_add_item(tree, hf_soc, tvb, offset, 4, ENC_TIME_SECS | ENC_BIG_ENDIAN);
	offset += 4;

	/* FRACSEC */
	/* time quality flags */
	temp_tree = proto_tree_add_subtree(tree, tvb, offset, 1, ett_timequal, NULL, "Time quality flags");
	proto_tree_add_item(temp_tree, hf_timeqal_lsdir,	 tvb, offset, 1, ENC_BIG_ENDIAN);
	proto_tree_add_item(temp_tree, hf_timeqal_lsocc,	 tvb, offset, 1, ENC_BIG_ENDIAN);
	proto_tree_add_item(temp_tree, hf_timeqal_lspend,	 tvb, offset, 1, ENC_BIG_ENDIAN);
	proto_tree_add_item(temp_tree, hf_timeqal_timequalindic, tvb, offset, 1, ENC_BIG_ENDIAN);
	offset += 1;

	// Add RAW FRACSEC
	proto_tree_add_item(tree, hf_fracsec_raw,  tvb, offset, 3, ENC_BIG_ENDIAN);

	// If exist configuration frame, add fracsec in milliseconds
	if (conf){
		uint32_t fracsec_raw = tvb_get_uint24(tvb, offset, ENC_BIG_ENDIAN);
		float	fracsec_ms = 1000.0f*fracsec_raw/conf->time_base;
		proto_tree_add_float(tree, hf_fracsec_ms, tvb, offset, 3, fracsec_ms);
	} else
	{
	}
	/*offset += 3;*/

	return framesize;
}

/* Dissects a single phasor for 'dissect_PHASORS()' */
static int dissect_single_phasor(tvbuff_t *tvb, int offset,
					double *mag, double *phase, /* returns the resulting values in polar format here */
					double* real, double* imag, /* returns the resulting values in rectangular format here*/
					double* mag_real_unscaled, double* phase_imag_unscaled, /* returns unscaled values*/
					config_block *block,	      /* information needed to... */
					phasor_info* pi)	      /*  ...dissect the phasor	*/
{
	if (floating_point == block->format_ph) {
		if (polar == block->phasor_notation) {
			/* float, polar */
			*mag   = tvb_get_ntohieee_float(tvb, offset    );
			*phase = tvb_get_ntohieee_float(tvb, offset + 4);

			*real = (*mag) * cos(*phase);
			*imag = (*mag) * sin(*phase);
		}
		else {
			/* float, rect */
			*real = tvb_get_ntohieee_float(tvb, offset    );
			*imag = tvb_get_ntohieee_float(tvb, offset + 4);

			*mag   = sqrt(pow(*real, 2) + pow(*imag, 2));
			*phase = atan2(*imag, *real);
		}
	}
	else {
		if (polar == block->phasor_notation) {
			/* int, polar */
			*mag_real_unscaled = tvb_get_ntohs(tvb, offset	);
			*phase_imag_unscaled = tvb_get_ntohis(tvb, offset + 2);

			/* For fixed-point data in polar format all values are permissible for the magnitude
			   field. However, the angle field is restricted to ±31416. A value of 0x8000 (–32768) used in the angle field
			   will be used to signify absent data.
			   bullet 6.3.1 page 16 IEEE Std C37.118.2-2011
			*/
			if (*phase_imag_unscaled == -32768) {
				*phase_imag_unscaled = NAN;
				*mag_real_unscaled = NAN;
			}

			*phase = *phase_imag_unscaled/10000.0; /* angle is in radians*10^4 */

			/* for values in integer format, consider conversation factor */
			if (block->cfg_frame_type == 3){
				*mag = (*mag_real_unscaled * pi->conv_cfg3);
				*phase = *phase - pi->angle_offset_cfg3;
			}
			else{
				*mag = (*mag_real_unscaled * pi->conv) * 0.00001;
			}

			*real = (*mag) * cos(*phase);
			*imag = (*mag) * sin(*phase);
		}
		else {
			/* int, rect */
			*mag_real_unscaled = tvb_get_ntohis(tvb, offset    );
			*phase_imag_unscaled = tvb_get_ntohis(tvb, offset + 2);

			/* For fixed-point data in rectangular format the PDC will use
			   0x8000 (–32768) as the substitute for the absent data.
			   bullet 6.3.1 page 16 IEEE Std C37.118.2-2011
			*/
			if (*mag_real_unscaled == -32768) {
				*mag_real_unscaled = NAN;
			}
			if (*phase_imag_unscaled == -32768) {
				*phase_imag_unscaled = NAN;
			}

			*mag = sqrt(pow(*mag_real_unscaled, 2) + pow(*phase_imag_unscaled, 2));
			*phase = atan2(*phase_imag_unscaled, *mag_real_unscaled);

			/* for values in integer format, consider conversation factor */
			if (block->cfg_frame_type == 3) {
				*mag = (*mag * pi->conv_cfg3);
				*phase = *phase - pi->angle_offset_cfg3;
			}
			else {
				*mag = (*mag * pi->conv) * 0.00001;
			}

			*real = (*mag) * cos(*phase);
			*imag = (*mag) * sin(*phase);
		}
	}

	return floating_point == block->format_ph ? 8 : 4;
}

/* used by 'dissect_data_frame()' to dissect the PHASORS field */
static int dissect_PHASORS(tvbuff_t *tvb, proto_tree *tree, config_block *block, int offset)
{
	proto_tree *phasor_tree;
	unsigned	    length;
	int	    j;
	int	    cnt = wmem_array_get_count(block->phasors); /* number of phasors to dissect */

	if (0 == cnt)
		return offset;

	length	    = wmem_array_get_count(block->phasors) * (floating_point == block->format_ph ? 8 : 4);
	phasor_tree = proto_tree_add_subtree_format(tree, tvb, offset, length, ett_data_phasors, NULL,
						    "Phasors (%u), notation: %s, format: %s", cnt,
							block->phasor_notation ? "polar" : "rectangular",
							block->format_ph ? "floating point" : "integer");

	/* dissect a phasor for every phasor_info saved in the config_block */
	for (j = 0; j < cnt; j++) {
		proto_item  *temp_item;
		double	     mag, phase,real, imag;
		double	     mag_real_unscaled = NAN, phase_imag_unscaled = NAN;
		phasor_info *pi;

		pi = (phasor_info *)wmem_array_index(block->phasors, j);
		temp_item = proto_tree_add_string_format(phasor_tree, hf_synphasor_phasor, tvb, offset,
						floating_point == block->format_ph ? 8 : 4, pi->name,
						"Phasor #%u: \"%s\"", j + 1, pi->name);

		offset += dissect_single_phasor(tvb, offset,
						&mag, &phase, &real, &imag,
						&mag_real_unscaled, &phase_imag_unscaled,
						block,pi);

		#define SYNP_ANGLE "\xe2\x88\xa0"      /*   8736 / 0x2220 */

		char phasor_unit = V == pi->unit ? 'V' : 'A';

		proto_item_append_text(temp_item, ", %10.3F%c " SYNP_ANGLE "%7.3F" UTF8_DEGREE_SIGN " alt %7.3F+j%7.3F%c",
			mag, phasor_unit, phase * 180.0 / G_PI,
			real, imag, phasor_unit);
		if (integer == block->format_ph) {
			proto_item_append_text(temp_item, "; unscaled: %5.0F, %5.0F",
				mag_real_unscaled, phase_imag_unscaled);
		}
		#undef SYNP_ANGLE
	}
	return offset;
}

/* used by 'dissect_data_frame()' to dissect the FREQ and DFREQ fields */
static int dissect_DFREQ(tvbuff_t *tvb, proto_tree *tree, config_block *block, int offset)
{
	if (floating_point == block->format_fr) {
		proto_tree_add_item(tree, hf_synphasor_actual_frequency_value, tvb, offset, 4, ENC_BIG_ENDIAN);
		offset += 4;

		/* In new version of the standard IEEE Std C37.118.2-2011: "Can be 16-bit integer or IEEE floating point, same as FREQ above."
		 * --> no scaling factor is applied to DFREQ
		 */
		proto_tree_add_item(tree, hf_synphasor_rate_change_frequency, tvb, offset, 4, ENC_BIG_ENDIAN);
		offset += 4;
	}
	else {
		int16_t tmp;

		tmp = tvb_get_ntohs(tvb, offset);
		proto_tree_add_int_format_value(tree, hf_synphasor_frequency_deviation_from_nominal, tvb, offset, 2, tmp,
				    "%dmHz (actual frequency: %.3fHz)", tmp, block->fnom + (tmp / 1000.0));
		offset += 2;

		tmp = tvb_get_ntohs(tvb, offset);
		proto_tree_add_float_format_value(tree, hf_synphasor_rate_change_frequency, tvb, offset, 2, (float)(tmp / 100.0), "%.3fHz/s", tmp / 100.0); offset += 2;
	}
	return offset;
}

/* used by 'dissect_data_frame()' to dissect the ANALOG field */
static int dissect_ANALOG(tvbuff_t *tvb, proto_tree *tree, config_block *block, int offset)
{
	proto_tree *analog_tree;
	unsigned	    length;
	int	    j;
	int	    cnt = wmem_array_get_count(block->analogs); /* number of analog values to dissect */

	if (0 == cnt)
		return offset;

	length	    = wmem_array_get_count(block->analogs) * (floating_point == block->format_an ? 4 : 2);
	analog_tree = proto_tree_add_subtree_format(tree, tvb, offset, length, ett_data_analog, NULL,
						    "Analog values (%u)", cnt);

	for (j = 0; j < cnt; j++) {
		proto_item *temp_item;
		analog_info *ai = (analog_info *)wmem_array_index(block->analogs, j);

		temp_item = proto_tree_add_string_format(analog_tree, hf_synphasor_analog_value, tvb, offset,
						floating_point == block->format_an ? 4 : 2, ai->name,
						"Analog value #%u: \"%s\"", j + 1, ai->name);

		if (block->cfg_frame_type == 3)
		{
			if (floating_point == block->format_an) {
				float tmp;

				tmp = tvb_get_ntohieee_float(tvb, offset);
				offset += 4;

				proto_item_append_text(temp_item, ", %.3f", tmp);
			}
			else {
				/* the "standard" doesn't say if this is signed or unsigned,
				* so I just use int16_t */
				int16_t tmp_i;
				float tmp_f;

				tmp_i = tvb_get_ntohs(tvb, offset);
				offset += 2;

				tmp_f = (tmp_i * ai->conv_cfg3) + ai->offset_cfg3;

				proto_item_append_text(temp_item, ", %.3f", tmp_f);
			}
		}
		else
		{
			if (floating_point == block->format_an) {
				float tmp = tvb_get_ntohieee_float(tvb, offset); offset += 4;
				proto_item_append_text(temp_item, ", %.3f", tmp);
			}
			else {
				/* the "standard" doesn't say if this is signed or unsigned,
				 * so I just use int16_t; the scaling of the conversion factor
				 * is also "user defined", so I just write it after the analog value */
				int16_t tmp = tvb_get_ntohs(tvb, offset); offset += 2;
				proto_item_append_text(temp_item, ", %" PRId16 " (conversion factor: %#06x)",
						       tmp, ai->conv);
			}
		}
	}
	return offset;
}

/* used by 'dissect_data_frame()' to dissect the DIGITAL field */
static int dissect_DIGITAL(tvbuff_t *tvb, proto_tree *tree, config_block *block, int offset)
{
	int	    j;
	int	    cnt = block->num_dg; /* number of digital status words to dissect */

	if (0 == cnt)
		return offset;

	tree = proto_tree_add_subtree_format(tree, tvb, offset, cnt * 2, ett_data_digital, NULL,
					     "Digital status words (%u)", cnt);

	for (j = 0; j < cnt; j++) {
		uint16_t tmp = tvb_get_ntohs(tvb, offset);
		proto_tree_add_uint_format(tree, hf_synphasor_digital_status_word, tvb, offset, 2, tmp, "Digital status word #%u: 0x%04x", j + 1, tmp);
		offset += 2;
	}
	return offset;
}

/* used by 'dissect_config_frame()' to dissect the PHUNIT field */
static int dissect_PHUNIT(tvbuff_t *tvb, proto_tree *tree, int offset, int cnt)
{
	proto_tree *temp_tree;
	int i;

	if (0 == cnt)
		return offset;

	temp_tree = proto_tree_add_subtree_format(tree, tvb, offset, 4 * cnt, ett_conf_phconv, NULL,
						  "Phasor conversion factors (%u)", cnt);

	/* Conversion factor for phasor channels. Four bytes for each phasor.
	 * MSB:		  0 = voltage, 1 = current
	 * Lower 3 Bytes: unsigned 24-bit word in 10^-5 V or A per bit to scale the phasor value
	 */
	for (i = 0; i < cnt; i++) {
		uint32_t tmp = tvb_get_ntohl(tvb, offset);
		proto_tree_add_uint_format(temp_tree, hf_synphasor_conversion_factor, tvb, offset, 4,
				    tmp, "#%u factor: %u * 10^-5, unit: %s",
				    i + 1,
				    tmp & 0x00FFFFFF,
				    tmp & 0xFF000000 ? "Ampere" : "Volt");
		offset += 4;
	}

	return offset;
}

/* used by 'dissect_config_3_frame()' to dissect the PHSCALE field */
static int dissect_PHSCALE(tvbuff_t *tvb, proto_tree *tree, int offset, int cnt)
{
	proto_tree *temp_tree;
	int i;

	if (0 == cnt) {
		return offset;
	}

	temp_tree = proto_tree_add_subtree_format(tree, tvb, offset, 12 * cnt, ett_conf_phconv, NULL,
						  "Phasor scaling and data flags (%u)", cnt);

	for (i = 0; i < cnt; i++) {
		proto_tree *single_phasor_scaling_and_flags_tree;
		proto_tree *phasor_flag1_tree;
		proto_tree *phasor_flag2_tree;
		proto_tree *data_flag_tree;

		single_phasor_scaling_and_flags_tree = proto_tree_add_subtree_format(temp_tree, tvb, offset, 12,
										     ett_conf_phlist, NULL,
										     "Phasor #%u", i + 1);

		data_flag_tree = proto_tree_add_subtree_format(single_phasor_scaling_and_flags_tree, tvb, offset, 4,
							       ett_conf_phflags, NULL, "Phasor Data flags: %s",
							       val_to_str_const(tvb_get_uint8(tvb, offset + 2), conf_phasor_type, "Unknown"));

		/* first and second bytes - phasor modification flags*/
		phasor_flag1_tree = proto_tree_add_subtree_format(data_flag_tree, tvb, offset, 2, ett_conf_phmod_flags,
								  NULL, "Modification Flags: 0x%04x",
								  tvb_get_ntohs(tvb, offset));

		proto_tree_add_item(phasor_flag1_tree, hf_conf_phasor_mod_b15, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(phasor_flag1_tree, hf_conf_phasor_mod_b10, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(phasor_flag1_tree, hf_conf_phasor_mod_b09, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(phasor_flag1_tree, hf_conf_phasor_mod_b08, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(phasor_flag1_tree, hf_conf_phasor_mod_b07, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(phasor_flag1_tree, hf_conf_phasor_mod_b06, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(phasor_flag1_tree, hf_conf_phasor_mod_b05, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(phasor_flag1_tree, hf_conf_phasor_mod_b04, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(phasor_flag1_tree, hf_conf_phasor_mod_b03, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(phasor_flag1_tree, hf_conf_phasor_mod_b02, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(phasor_flag1_tree, hf_conf_phasor_mod_b01, tvb, offset, 2, ENC_BIG_ENDIAN);
		offset += 2;

		/* third byte - phasor type*/
		proto_tree_add_item(data_flag_tree, hf_conf_phasor_type_b03, tvb, offset, 1, ENC_BIG_ENDIAN);
		proto_tree_add_item(data_flag_tree, hf_conf_phasor_type_b02to00, tvb, offset, 1, ENC_BIG_ENDIAN);
		offset += 1;

		/* fourth byte - user designation*/
		phasor_flag2_tree = proto_tree_add_subtree_format(data_flag_tree, tvb, offset, 1, ett_conf_ph_user_flags,
								  NULL, "User designated flags: 0x%02x",
								  tvb_get_uint8(tvb, offset));

		proto_tree_add_item(phasor_flag2_tree, hf_conf_phasor_user_data, tvb, offset, 1, ENC_BIG_ENDIAN);
		offset += 1;

		/* phasor scalefactor */
		proto_tree_add_item(single_phasor_scaling_and_flags_tree, hf_conf_phasor_scale_factor,
				    tvb, offset, 4, ENC_BIG_ENDIAN);
		offset += 4;

		/* angle adjustment */
		proto_tree_add_item(single_phasor_scaling_and_flags_tree, hf_conf_phasor_angle_offset,
				    tvb, offset, 4, ENC_BIG_ENDIAN);
		offset += 4;
	}

	return offset;
}

/* used by 'dissect_config_frame()' to dissect the ANUNIT field */
static int dissect_ANUNIT(tvbuff_t *tvb, proto_tree *tree, int offset, int cnt)
{
	proto_item *temp_item;
	proto_tree *temp_tree;
	int i;

	if (0 == cnt)
		return offset;

	temp_tree = proto_tree_add_subtree_format(tree, tvb, offset, 4 * cnt, ett_conf_anconv, NULL,
						  "Analog values conversion factors (%u)", cnt);

	/* Conversion factor for analog channels. Four bytes for each analog value.
	 * MSB: see 'synphasor_conf_anconvnames' in 'synphasor_strings.c'
	 * Lower 3 Bytes: signed 24-bit word, user-defined scaling
	 */
	for (i = 0; i < cnt; i++) {
		int32_t tmp = tvb_get_ntohl(tvb, offset);
		temp_item = proto_tree_add_uint_format(temp_tree, hf_synphasor_factor_for_analog_value, tvb, offset, 4,
						tmp, "Factor for analog value #%i: %s",
						i + 1,
						try_rval_to_str((tmp >> 24) & 0x000000FF, conf_anconvnames));

		tmp &= 0x00FFFFFF;
		if (	tmp &  0x00800000) /* sign bit set */
			tmp |= 0xFF000000;

		proto_item_append_text(temp_item, ", value: %" PRId32, tmp);

		offset += 4;
	}

	return offset;
}

/* used by 'dissect_config_3_frame()' to dissect the ANSCALE field */
static int dissect_ANSCALE(tvbuff_t *tvb, proto_tree *tree, int offset, int cnt)
{
	proto_tree *temp_tree;
	int i;

	if (0 == cnt) {
		return offset;
	}

	temp_tree = proto_tree_add_subtree_format(tree, tvb, offset, 8 * cnt, ett_conf_anconv, NULL,
						  "Analog values conversion factors (%u)", cnt);

	/* Conversion factor for analog channels. Four bytes for each analog value.
	 * MSB: see 'synphasor_conf_anconvnames' in 'synphasor_strings.c'
	 * Lower 3 Bytes: signed 24-bit word, user-defined scaling
	 */
	for (i = 0; i < cnt; i++) {
		proto_tree *single_analog_scalefactor_tree;

		single_analog_scalefactor_tree = proto_tree_add_subtree_format(temp_tree, tvb, offset, 8,
									       ett_conf_phlist, NULL,
									       "Analog #%u", i + 1);

		/* analog scalefactor */
		proto_tree_add_item(single_analog_scalefactor_tree, hf_conf_analog_scale_factor,
				    tvb, offset, 4, ENC_BIG_ENDIAN);
		offset += 4;

		/* angle adjustment */
		proto_tree_add_item(single_analog_scalefactor_tree, hf_conf_analog_offset,
				    tvb, offset, 4, ENC_BIG_ENDIAN);
		offset += 4;
	}

	return offset;
}

/* used by 'dissect_config_frame()' to dissect the DIGUNIT field */
static int dissect_DIGUNIT(tvbuff_t *tvb, proto_tree *tree, int offset, int cnt)
{
	proto_tree *temp_tree, *mask_tree;
	int i;

	if (0 == cnt)
		return offset;

	temp_tree = proto_tree_add_subtree_format(tree, tvb, offset, 4 * cnt, ett_conf_dgmask, NULL,
						  "Masks for digital status words (%u)", cnt);

	/* Mask words for digital status words. Two 16-bit words for each digital word. The first
	 * indicates the normal status of the inputs, the second indicated the valid bits in
	 * the status word
	 */
	for (i = 0; i < cnt; i++) {

		mask_tree = proto_tree_add_subtree_format(temp_tree, tvb, offset, 4, ett_status_word_mask, NULL, "Mask for status word #%u: ", i + 1);
		proto_tree_add_item(mask_tree, hf_synphasor_status_word_mask_normal_state, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2;
		proto_tree_add_item(mask_tree, hf_synphasor_status_word_mask_valid_bits, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2;
	}

	return offset;
}

/* used by 'dissect_config_frame()' to dissect the "channel name"-fields */
static int dissect_CHNAM(tvbuff_t *tvb, proto_tree *tree, int offset, int cnt, const char *prefix)
{
	proto_tree *temp_tree;
	int i;

	if (0 == cnt)
		return offset;

	temp_tree = proto_tree_add_subtree_format(tree, tvb, offset, CHNAM_LEN * cnt, ett_conf_phnam, NULL,
						  "%ss (%u)", prefix, cnt);

	/* dissect the 'cnt' channel names */
	for (i = 0; i < cnt; i++) {
		char *str;
		str = (char *)tvb_get_string_enc(wmem_packet_scope(), tvb, offset, CHNAM_LEN, ENC_ASCII);
		proto_tree_add_string_format(temp_tree, hf_synphasor_channel_name, tvb, offset, CHNAM_LEN,
				    str, "%s #%i: \"%s\"", prefix, i+1, str);
		offset += CHNAM_LEN;
	}

	return offset;
}

/* used by 'dissect_config_3_frame()' to dissect the "channel name"-fields */
static int dissect_config_3_CHNAM(tvbuff_t *tvb, proto_tree *tree, int offset, int cnt, const char *prefix)
{
	proto_tree *temp_tree, *chnam_tree;
	int i;
	uint8_t name_length;
	int temp_offset;
	int subsection_length = 0;

	if (0 == cnt) {
		return offset;
	}

	/* get the subsection length */
	temp_offset = offset;
	for (i = 0; i < cnt; i++) {
		name_length = get_name_length(tvb, temp_offset);
		/* count the length byte and the actual name */
		subsection_length += name_length + 1;
		temp_offset += name_length + 1;
	}

	temp_tree = proto_tree_add_subtree_format(tree, tvb, offset, subsection_length, ett_conf_phnam,
						  NULL, "%ss (%u)", prefix, cnt);

	/* dissect the 'cnt' channel names */
	for (i = 0; i < cnt; i++) {
		char *str;

		name_length = get_name_length(tvb, offset);
		str = (char *)tvb_get_string_enc(wmem_packet_scope(), tvb, offset + 1, name_length, ENC_ASCII);
		chnam_tree = proto_tree_add_subtree_format(temp_tree, tvb, offset, name_length + 1, ett_conf,
							   NULL, "%s #%i: \"%s\"", prefix, i + 1, str);

		proto_tree_add_item(chnam_tree, hf_conf_chnam_len, tvb, offset, 1, ENC_BIG_ENDIAN);
		offset += 1;

		proto_tree_add_string(chnam_tree, hf_conf_chnam, tvb, offset, 1, str);
		offset += name_length;
	}

	return offset;
}

/* dissects a configuration frame (type 1 and 2) and adds fields to 'config_item' */
static int dissect_config_frame(tvbuff_t *tvb, proto_item *config_item)
{
	proto_tree *config_tree;
	int	    offset = 0;
	uint16_t	    num_pmu, j;

	proto_item_set_text   (config_item, "Configuration data");
	config_tree = proto_item_add_subtree(config_item, ett_conf);

	/* TIME_BASE and NUM_PMU */
	offset += 1; /* skip the reserved byte */
	proto_tree_add_item(config_tree, hf_conf_timebase, tvb, offset, 3, ENC_BIG_ENDIAN); offset += 3;
	proto_tree_add_item(config_tree, hf_conf_numpmu,   tvb, offset, 2, ENC_BIG_ENDIAN);
	/* add number of included PMUs to the text in the list view  */
	num_pmu = tvb_get_ntohs(tvb, offset); offset += 2;
	proto_item_append_text(config_item, ", %"PRIu16" PMU(s) included", num_pmu);

	/* dissect the repeating PMU blocks */
	for (j = 0; j < num_pmu; j++) {
		uint16_t	    num_ph, num_an, num_dg;
		proto_item *station_item;
		proto_tree *station_tree;
		proto_tree *temp_tree;
		char	   *str;

		int oldoffset = offset; /* to calculate the length of the whole PMU block later */

		/* STN with new tree to add the rest of the PMU block */
		str = (char *)tvb_get_string_enc(wmem_packet_scope(), tvb, offset, CHNAM_LEN, ENC_ASCII);
		station_tree = proto_tree_add_subtree_format(config_tree, tvb, offset, CHNAM_LEN,
							     ett_conf_station, &station_item,
							     "Station #%i: \"%s\"", j + 1, str);
		offset += CHNAM_LEN;

		/* IDCODE */
		proto_tree_add_item(station_tree, hf_idcode_data_source, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2;

		/* FORMAT */
		temp_tree = proto_tree_add_subtree(station_tree, tvb, offset, 2, ett_conf_format, NULL,
						   "Data format in data frame");
		proto_tree_add_item(temp_tree, hf_conf_formatb3, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(temp_tree, hf_conf_formatb2, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(temp_tree, hf_conf_formatb1, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(temp_tree, hf_conf_formatb0, tvb, offset, 2, ENC_BIG_ENDIAN);
		offset += 2;

		/* PHNMR, ANNMR, DGNMR */
		num_ph = tvb_get_ntohs(tvb, offset    );
		num_an = tvb_get_ntohs(tvb, offset + 2);
		num_dg = tvb_get_ntohs(tvb, offset + 4);
		proto_tree_add_uint(station_tree, hf_synphasor_num_phasors, tvb, offset, 2, num_ph);
		proto_tree_add_uint(station_tree, hf_synphasor_num_analog_values, tvb, offset + 2, 2, num_an);
		proto_tree_add_uint(station_tree, hf_synphasor_num_digital_status_words, tvb, offset + 4, 2, num_dg);
		offset += 6;

		/* CHNAM, the channel names */
		offset = dissect_CHNAM(tvb, station_tree, offset, num_ph     , "Phasor name"	     );
		offset = dissect_CHNAM(tvb, station_tree, offset, num_an     , "Analog value"	     );
		offset = dissect_CHNAM(tvb, station_tree, offset, num_dg * 16, "Digital status label");

		/* PHUNIT, ANUINT and DIGUNIT */
		offset = dissect_PHUNIT (tvb, station_tree, offset, num_ph);
		offset = dissect_ANUNIT (tvb, station_tree, offset, num_an);
		offset = dissect_DIGUNIT(tvb, station_tree, offset, num_dg);

		/* FNOM and CFGCNT */
		proto_tree_add_item(station_tree, hf_conf_fnom,	  tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2;
		proto_tree_add_item(station_tree, hf_conf_cfgcnt, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2;

		/* set the correct length for the "Station :" item */
		proto_item_set_len(station_item, offset - oldoffset);
	} /* for() PMU blocks */

	/* DATA_RATE */
	{
		int16_t tmp = tvb_get_ntohis(tvb, offset);
		if (tmp > 0)
			proto_tree_add_int_format_value(config_tree, hf_synphasor_rate_of_transmission, tvb, offset, 2, tmp,
                        "%d frame(s) per second", tmp);
		else
			proto_tree_add_int_format_value(config_tree, hf_synphasor_rate_of_transmission, tvb, offset, 2, tmp,
                        "1 frame per %d second(s)", (int16_t)-tmp);
		offset += 2;
	}

	return offset;
} /* dissect_config_frame() */

/* dissects a configuration frame type 3 and adds fields to 'config_item' */
static int dissect_config_3_frame(tvbuff_t *tvb, proto_item *config_item)
{
	proto_tree *config_tree, *wgs84_tree;
	int	    offset = 0;
	uint16_t	    num_pmu, j;

	proto_item_set_text(config_item, "Configuration data");
	config_tree = proto_item_add_subtree(config_item, ett_conf);

	/* CONT_IDX */
	proto_tree_add_item(config_tree, hf_cont_idx, tvb, offset, 2, ENC_BIG_ENDIAN);
	offset += 2;

	/* TIME_BASE and NUM_PMU */
	offset += 1; /* skip the reserved byte */

	proto_tree_add_item(config_tree, hf_conf_timebase, tvb, offset, 3, ENC_BIG_ENDIAN);
	offset += 3;

	proto_tree_add_item(config_tree, hf_conf_numpmu,   tvb, offset, 2, ENC_BIG_ENDIAN);

	/* add number of included PMUs to the text in the list view  */
	num_pmu = tvb_get_ntohs(tvb, offset);
	offset += 2;

	proto_item_append_text(config_item, ", %"PRIu16" PMU(s) included", num_pmu);

	/* dissect the repeating PMU blocks */
	for (j = 0; j < num_pmu; j++) {
		uint16_t   num_ph, num_an, num_dg, i;
		uint8_t    name_length;
		int        oldoffset;
		float      pmu_lat, pmu_long, pmu_elev;
		proto_item *station_item;
		proto_tree *station_tree;
		proto_tree *temp_tree;
		char       *str, *service_class;
		char       *unspecified_location = "Unspecified Location";
		uint8_t    g_pmu_id_array[G_PMU_ID_LEN];

		oldoffset = offset; /* to calculate the length of the whole PMU block later */

		/* STN with new tree to add the rest of the PMU block */
		name_length = get_name_length(tvb, offset);
		str = (char *)tvb_get_string_enc(wmem_packet_scope(), tvb, offset + 1, name_length, ENC_ASCII);
		station_tree = proto_tree_add_subtree_format(config_tree, tvb, offset, name_length + 1,
							     ett_conf_station, &station_item,
							     "Station #%i: \"%s\"", j + 1, str);

		/* Station Name Length */
		proto_tree_add_item(station_tree, hf_station_name_len, tvb, offset, 1, ENC_BIG_ENDIAN);
		offset += 1;

		/* Station Name */
		proto_tree_add_string(station_tree, hf_station_name, tvb, offset, 1, str);
		offset += name_length;

		/* IDCODE */
		proto_tree_add_item(station_tree, hf_idcode_data_source, tvb, offset, 2, ENC_BIG_ENDIAN);
		offset += 2;

		/* G_PMU_ID */
		/* A 128 bit display as raw bytes */
		for (i = 0; i < G_PMU_ID_LEN; i++) {
			g_pmu_id_array[i] = tvb_get_uint8(tvb, offset + i);
		}

		proto_tree_add_bytes_format(station_tree, hf_g_pmu_id, tvb, offset, G_PMU_ID_LEN, 0,
					    "Global PMU ID (raw bytes): %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
					    g_pmu_id_array[0], g_pmu_id_array[1], g_pmu_id_array[2], g_pmu_id_array[3],
					    g_pmu_id_array[4], g_pmu_id_array[5], g_pmu_id_array[6], g_pmu_id_array[7],
					    g_pmu_id_array[8], g_pmu_id_array[9], g_pmu_id_array[10], g_pmu_id_array[11],
					    g_pmu_id_array[12], g_pmu_id_array[13], g_pmu_id_array[14], g_pmu_id_array[15]);
		offset += G_PMU_ID_LEN;

		/* FORMAT */
		temp_tree = proto_tree_add_subtree(station_tree, tvb, offset, 2, ett_conf_format, NULL,
						   "Data format in data frame");
		proto_tree_add_item(temp_tree, hf_conf_formatb3, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(temp_tree, hf_conf_formatb2, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(temp_tree, hf_conf_formatb1, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(temp_tree, hf_conf_formatb0, tvb, offset, 2, ENC_BIG_ENDIAN);
		offset += 2;

		/* PHNMR, ANNMR, DGNMR */
		num_ph = tvb_get_ntohs(tvb, offset    );
		num_an = tvb_get_ntohs(tvb, offset + 2);
		num_dg = tvb_get_ntohs(tvb, offset + 4);
		proto_tree_add_uint(station_tree, hf_synphasor_num_phasors, tvb, offset, 2, num_ph);
		proto_tree_add_uint(station_tree, hf_synphasor_num_analog_values, tvb, offset + 2, 2, num_an);
		proto_tree_add_uint(station_tree, hf_synphasor_num_digital_status_words, tvb, offset + 4, 2, num_dg);
		offset += 6;

		/* CHNAM, the channel names */
		offset = dissect_config_3_CHNAM(tvb, station_tree, offset, num_ph, "Phasor name");
		offset = dissect_config_3_CHNAM(tvb, station_tree, offset, num_an, "Analog value");
		offset = dissect_config_3_CHNAM(tvb, station_tree, offset, num_dg * 16, "Digital label");

		/* PHUNIT, ANUINT and DIGUNIT */
		offset = dissect_PHSCALE(tvb, station_tree, offset, num_ph);
		offset = dissect_ANSCALE(tvb, station_tree, offset, num_an);

		offset = dissect_DIGUNIT(tvb, station_tree, offset, num_dg);

		/* subtree for coordinate info*/
		wgs84_tree = proto_tree_add_subtree_format(station_tree, tvb, offset, 12, ett_conf_wgs84, NULL,
							   "World Geodetic System 84 data");

		/* preview latitude, longitude, and elevation values */
		/* INFINITY is an unspecified location, otherwise use the actual float value */
		pmu_lat = tvb_get_ntohieee_float(tvb, offset);
		pmu_long = tvb_get_ntohieee_float(tvb, offset + 4);
		pmu_elev = tvb_get_ntohieee_float(tvb, offset + 8);

		/* PMU_LAT */
		if (isinf(pmu_lat)) {
			proto_tree_add_float_format_value(wgs84_tree, hf_conf_pmu_lat_unknown, tvb, offset,
					      4, INFINITY, "%s", unspecified_location);
		}
		else {
			proto_tree_add_item(wgs84_tree, hf_conf_pmu_lat, tvb, offset, 4, ENC_BIG_ENDIAN);
		}
		offset += 4;

		/* PMU_LON */
		if (isinf(pmu_long)) {
			proto_tree_add_float_format_value(wgs84_tree, hf_conf_pmu_lon_unknown, tvb, offset,
					      4, INFINITY, "%s", unspecified_location);
		}
		else {
			proto_tree_add_item(wgs84_tree, hf_conf_pmu_lon, tvb, offset, 4, ENC_BIG_ENDIAN);
		}
		offset += 4;

		/* PMU_ELEV */
		if (isinf(pmu_elev)) {
			proto_tree_add_float_format_value(wgs84_tree, hf_conf_pmu_elev_unknown, tvb, offset,
					      4, INFINITY, "%s", unspecified_location);
		}
		else {
			proto_tree_add_item(wgs84_tree, hf_conf_pmu_elev, tvb, offset, 4, ENC_BIG_ENDIAN);
		}
		offset += 4;

		/* SVC_CLASS */
		service_class = (char *)tvb_get_string_enc(wmem_packet_scope(), tvb, offset, 1, ENC_ASCII);
		if ((strcmp(service_class, "P") == 0) || (strcmp(service_class, "p") == 0)) {
			proto_tree_add_string(station_tree, hf_conf_svc_class, tvb, offset, 1, "Protection");
		}
		else if ((strcmp(service_class, "M") == 0) || (strcmp(service_class, "m") == 0)) {
			proto_tree_add_string(station_tree, hf_conf_svc_class, tvb, offset, 1, "Monitoring");
		}
		else {
			proto_tree_add_string(station_tree, hf_conf_svc_class, tvb, offset, 1, "Unknown");
		}
		offset += 1;

		/* WINDOW */
		proto_tree_add_item(station_tree, hf_conf_window, tvb, offset, 4, ENC_BIG_ENDIAN);
		offset += 4;

		/*GRP_DLY */
		proto_tree_add_item(station_tree, hf_conf_grp_dly, tvb, offset, 4, ENC_BIG_ENDIAN);
		offset += 4;

		/* FNOM and CFGCNT */
		proto_tree_add_item(station_tree, hf_conf_fnom,	  tvb, offset, 2, ENC_BIG_ENDIAN);
		offset += 2;

		proto_tree_add_item(station_tree, hf_conf_cfgcnt, tvb, offset, 2, ENC_BIG_ENDIAN);
		offset += 2;

		/* set the correct length for the "Station :" item */
		proto_item_set_len(station_item, offset - oldoffset);
	} /* for() PMU blocks */

	/* DATA_RATE */
	{
		int16_t tmp = tvb_get_ntohis(tvb, offset);
		if (tmp > 0) {
			proto_tree_add_int_format_value(config_tree, hf_synphasor_rate_of_transmission, tvb, offset, 2, tmp,
							"%d frame(s) per second", tmp);
		}
		else {
			proto_tree_add_int_format_value(config_tree, hf_synphasor_rate_of_transmission, tvb, offset, 2, tmp,
							"1 frame per %d second(s)", (int16_t)-tmp);
		}
		offset += 2;
	}

	return offset;
} /* dissect_config_3_frame() */

/* calculates the size (in bytes) of a data frame that the config_block describes */
#define SYNP_BLOCKSIZE(x) (2							   /* STAT    */ \
		   + wmem_array_get_count((x).phasors) * (integer == (x).format_ph ? 4 : 8) /* PHASORS */ \
		   +			                 (integer == (x).format_fr ? 4 : 8) /* (D)FREQ */ \
		   + wmem_array_get_count((x).analogs) * (integer == (x).format_an ? 2 : 4) /* ANALOG  */ \
		   + (x).num_dg * 2)					   /* DIGITAL */

/* Dissects a data frame */
static int dissect_data_frame(tvbuff_t	  *tvb,
			      proto_item  *data_item, /* all items are placed beneath this item	  */
			      packet_info *pinfo)     /* used to find the data from a CFG-2 or CFG-3 frame */
{
	proto_tree	*data_tree;
	int		offset	 = 0;
	unsigned		i;
	config_frame	*conf;

	proto_item_set_text(data_item, "Measurement data");
	data_tree = proto_item_add_subtree(data_item, ett_data);

	/* search for configuration information to dissect the frame */
	{
		bool config_found = false;
		conf = (config_frame *)p_get_proto_data(wmem_file_scope(), pinfo, proto_synphasor, 0);

		if (conf) {
			/* check if the size of the current frame is the
			   size of the frame the config_frame describes */
			size_t reported_size = 0;
			for (i = 0; i < wmem_array_get_count(conf->config_blocks); i++) {
				config_block *block = (config_block*)wmem_array_index(conf->config_blocks, i);
				reported_size += SYNP_BLOCKSIZE(*block);
			}

			if (tvb_reported_length(tvb) == reported_size) {
				// Add link to CFG Frame
				proto_item* item = proto_tree_add_uint(data_tree, hf_cfg_frame_num, tvb, 0,0, conf->fnum);
				proto_item_set_generated(item);
				config_found = true;
			}
		}

		if (!config_found) {
			proto_item_append_text(data_item, ", no configuration frame found");
			return 0;
		}
	}

	/* dissect a PMU block for every config_block in the frame */
	for (i = 0; i < wmem_array_get_count(conf->config_blocks); i++) {
		config_block *block = (config_block*)wmem_array_index(conf->config_blocks, i);

		proto_tree *block_tree = proto_tree_add_subtree_format(data_tree, tvb, offset, SYNP_BLOCKSIZE(*block),
								       ett_data_block, NULL,
								       "Station: \"%s\"", block->name);

		/* STAT */
		proto_tree *temp_tree = proto_tree_add_subtree(block_tree, tvb, offset, 2, ett_data_stat, NULL, "Flags");

		proto_item *temp_item = proto_tree_add_item(temp_tree, hf_data_statb15to14, tvb, offset, 2, ENC_BIG_ENDIAN);
		uint16_t flag_bits = tvb_get_uint16(tvb, offset, ENC_BIG_ENDIAN)  >> 14; // Get bits 15-14
		if (flag_bits != 0) {
			expert_add_info(pinfo, temp_item, &ei_synphasor_data_error);
		}
		temp_item = proto_tree_add_item(temp_tree, hf_data_statb13,	    tvb, offset, 2, ENC_BIG_ENDIAN);
		flag_bits = tvb_get_uint16(tvb, offset, ENC_BIG_ENDIAN); // Get flag bits
		if ((flag_bits >> 13)&1) { // Check 13 bit
			expert_add_info(pinfo, temp_item, &ei_synphasor_pmu_not_sync);
		}
		proto_tree_add_item(temp_tree, hf_data_statb12,	    tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(temp_tree, hf_data_statb11,	    tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(temp_tree, hf_data_statb10,	    tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(temp_tree, hf_data_statb09,	    tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(temp_tree, hf_data_statb08to06, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(temp_tree, hf_data_statb05to04, tvb, offset, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(temp_tree, hf_data_statb03to00, tvb, offset, 2, ENC_BIG_ENDIAN);
		offset += 2;

		/* PHASORS, (D)FREQ, ANALOG, and DIGITAL */
		offset = dissect_PHASORS(tvb, block_tree, block, offset);
		offset = dissect_DFREQ	(tvb, block_tree, block, offset);
		offset = dissect_ANALOG (tvb, block_tree, block, offset);
		offset = dissect_DIGITAL(tvb, block_tree, block, offset);
	}
	return offset;
} /* dissect_data_frame() */

/* Dissects a command frame and adds fields to config_item.
 *
 * 'pinfo' is used to add the type of command
 * to the INFO column in the packet list.
 */
static int dissect_command_frame(tvbuff_t    *tvb,
				 proto_item  *command_item,
				 packet_info *pinfo)
{
	proto_tree *command_tree;
	unsigned	    tvbsize	  = tvb_reported_length(tvb);
	const char *s;

	proto_item_set_text(command_item, "Command data");
	command_tree = proto_item_add_subtree(command_item, ett_command);

	/* CMD */
	proto_tree_add_item(command_tree, hf_command, tvb, 0, 2, ENC_BIG_ENDIAN);

	s = rval_to_str_const(tvb_get_ntohs(tvb, 0), command_names, "invalid command");
	col_append_str(pinfo->cinfo, COL_INFO, ", ");
	col_append_str(pinfo->cinfo, COL_INFO, s);

	if (tvbsize > 2) {
		if (tvb_get_ntohs(tvb, 0) == 0x0008) {
			/* Command: Extended Frame, the extra data is ok */
			proto_item *ti = proto_tree_add_item(command_tree, hf_synphasor_extended_frame_data, tvb, 2, tvbsize - 2, ENC_NA);
			if (tvbsize % 2)
				expert_add_info(pinfo, ti, &ei_synphasor_extended_frame_data);
		}
		else
			proto_tree_add_item(command_tree, hf_synphasor_unknown_data, tvb, 2, tvbsize - 2, ENC_NA);
	}

	return tvbsize;
} /* dissect_command_frame() */

/* Dissects the header (common to all types of frames) and then calls
 * one of the subdissectors (declared above) for the rest of the frame.
 */
static int dissect_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
	uint8_t	frame_type;
	uint16_t crc;
	unsigned	tvbsize = tvb_reported_length(tvb);

	/* some heuristics */
	if (tvbsize < 17		    /* 17 bytes = header frame with only a
					       NULL character, useless but valid */
	 || tvb_get_uint8(tvb, 0) != 0xAA) /* every synchrophasor frame starts with 0xAA */
		return 0;

	/* write the protocol name to the info column */
	col_set_str(pinfo->cinfo, COL_PROTOCOL, PSNAME);

	frame_type = tvb_get_uint8(tvb, 1) >> 4;

	col_set_str(pinfo->cinfo, COL_INFO, val_to_str_const(frame_type, typenames, "invalid packet type"));

	/* CFG-2, CFG3, and DATA frames need special treatment during the first run:
	 * For CFG-2 & CFG-3 frames, a 'config_frame' struct is created to hold the
	 * information necessary to decode DATA frames. A pointer to this
	 * struct is saved in the conversation and is copied to the
	 * per-packet information if a DATA frame is dissected.
	 */
	if (!pinfo->fd->visited) {
		if (CFG2 == frame_type &&
		    check_crc(tvb, &crc)) {
			conversation_t *conversation;

			/* fill the config_frame */
			config_frame *frame = config_frame_fast(tvb);
			frame->fnum = pinfo->num;

			/* find a conversation, create a new one if none exists */
			conversation = find_or_create_conversation(pinfo);

			/* remove data from a previous CFG-2 frame, only
			 * the most recent configuration frame is relevant */
			if (conversation_get_proto_data(conversation, proto_synphasor))
				conversation_delete_proto_data(conversation, proto_synphasor);

			conversation_add_proto_data(conversation, proto_synphasor, frame);
		}
		else if ((CFG3 == frame_type) && check_crc(tvb, &crc)) {
			conversation_t *conversation;
			config_frame *frame;

			/* fill the config_frame */
			frame = config_3_frame_fast(tvb);
			frame->fnum = pinfo->num;

			/* find a conversation, create a new one if none exists */
			conversation = find_or_create_conversation(pinfo);

			/* remove data from a previous CFG-3 frame, only
			 * the most recent configuration frame is relevant */
			if (conversation_get_proto_data(conversation, proto_synphasor)) {
				conversation_delete_proto_data(conversation, proto_synphasor);
			}

			conversation_add_proto_data(conversation, proto_synphasor, frame);
		}
		// Add conf to any frame for dissection fracsec
		conversation_t *conversation = find_conversation_pinfo(pinfo, 0);
		if (conversation) {
			config_frame *conf = (config_frame *)conversation_get_proto_data(conversation, proto_synphasor);
			/* no problem if 'conf' is NULL, the frame dissector checks this again */
		p_add_proto_data(wmem_file_scope(), pinfo, proto_synphasor, 0, conf);
		}
	} /* if (!visited) */

	{
		proto_tree *synphasor_tree;
		proto_item *temp_item;
		proto_item *sub_item;

		int	    offset;
		uint16_t	    framesize;
		tvbuff_t   *sub_tvb;
		bool       crc_good;

		temp_item = proto_tree_add_item(tree, proto_synphasor, tvb, 0, -1, ENC_NA);
		proto_item_append_text(temp_item, ", %s", val_to_str_const(frame_type, typenames,
									   ", invalid packet type"));

		/* synphasor_tree is where from now on all new elements for this protocol get added */
		synphasor_tree = proto_item_add_subtree(temp_item, ett_synphasor);
		// Add pinfo for dissection fracsec
		framesize = dissect_header(tvb, synphasor_tree, pinfo);
		offset = 14; /* header is 14 bytes long */

		/* check CRC, call appropriate subdissector for the rest of the frame if CRC is correct*/
		sub_item  = proto_tree_add_item(synphasor_tree, hf_synphasor_data, tvb, offset, tvbsize - 16, ENC_NA);
		crc_good = check_crc(tvb, &crc);
		proto_tree_add_checksum(synphasor_tree, tvb, tvbsize - 2, hf_synphasor_checksum, hf_synphasor_checksum_status, &ei_synphasor_checksum,
								pinfo, crc16_x25_ccitt_tvb(tvb, tvb_get_ntohs(tvb, 2) - 2), ENC_BIG_ENDIAN, PROTO_CHECKSUM_VERIFY);
		if (!crc_good) {
			proto_item_append_text(sub_item,  ", not dissected because of wrong checksum");
		}
		else {
			/* create a new tvb to pass to the subdissector
			   '-16': length of header + 2 CRC bytes */
			sub_tvb = tvb_new_subset_length_caplen(tvb, offset, tvbsize - 16, framesize - 16);

			/* call subdissector */
			switch (frame_type) {
				case DATA:
					dissect_data_frame(sub_tvb, sub_item, pinfo);
					break;
				case HEADER: /* no further dissection is done/needed */
					proto_item_append_text(sub_item, "Header Frame");
					break;
				case CFG1:
				case CFG2:
					dissect_config_frame(sub_tvb, sub_item);
					break;
				case CMD:
					dissect_command_frame(sub_tvb, sub_item, pinfo);
					break;
				case CFG3:
					/* Note:  The C37.118-2.2001 stanadard is vague on how to handle fragmented frames.
						  Until further clarification is given, fragmented frames with the CONT_IDX
						  are not supported. */
					if (tvb_get_uint16(tvb, offset, ENC_BIG_ENDIAN) != 0) {
						proto_item_append_text(sub_item, ", CFG-3 Fragmented Frame (Not Supported)");
					}
					else {
						dissect_config_3_frame(sub_tvb, sub_item);
					}
					break;
				default:
					proto_item_append_text(sub_item, " of unknown type");
			}
			proto_item_append_text(temp_item, " [correct]");
		}

		/* remaining 2 bytes are the CRC */
	}

	return tvb_reported_length(tvb);
} /* dissect_common() */

/* called for synchrophasors over UDP */
static int dissect_udp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
	return dissect_common(tvb, pinfo, tree, data);
}

/* callback for 'tcp_dissect_pdus()' to give it the length of the frame */
static unsigned get_pdu_length(packet_info *pinfo _U_, tvbuff_t *tvb,
                            int offset, void *data _U_)
{
	return tvb_get_ntohs(tvb, offset + 2);
}

static int dissect_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
	tcp_dissect_pdus(tvb, pinfo, tree, true, 4, get_pdu_length, dissect_common, data);

	return tvb_reported_length(tvb);
}

/*******************************************************************/
/* after this line:  Wireshark Register Routines                   */
/*******************************************************************/

/* Register Synchrophasor Protocol with Wireshark*/
void proto_register_synphasor(void)
{
	static hf_register_info hf[] = {
		/* Sync word */
		{ &hf_sync,
		{ "Synchronization word", "synphasor.sync", FT_UINT16, BASE_HEX,
		  NULL, 0x0, NULL, HFILL }},

		/* Flags in the Sync word */
			{ &hf_sync_frtype,
			{ "Frame Type", "synphasor.frtype", FT_UINT16, BASE_HEX,
			   VALS(typenames), 0x0070, NULL, HFILL }},

			{ &hf_sync_version,
			{ "Version",	"synphasor.version", FT_UINT16, BASE_DEC,
			  VALS(versionnames), 0x000F, NULL, HFILL }},

		{ &hf_frsize,
		{ "Framesize", "synphasor.frsize", FT_UINT16, BASE_DEC | BASE_UNIT_STRING,
		  UNS(&units_byte_bytes), 0x0, NULL, HFILL }},

		{ &hf_station_name_len,
		{ "Station name length", "synphasor.station_name_len", FT_UINT8,
		  BASE_DEC | BASE_UNIT_STRING, UNS(&units_byte_bytes), 0x0, NULL, HFILL }},

		{ &hf_station_name,
		{ "Station name", "synphasor.station_name", FT_STRING, BASE_NONE,
		  NULL, 0x0, NULL, HFILL }},

		{ &hf_idcode_stream_source,
		{ "PMU/DC ID number (Stream source ID)", "synphasor.idcode_stream_source", FT_UINT16, BASE_DEC,
		  NULL, 0x0, NULL, HFILL }},

		{ &hf_idcode_data_source,
		{ "PMU/DC ID number (Data source ID)", "synphasor.idcode_data_source", FT_UINT16, BASE_DEC,
		  NULL, 0x0, NULL, HFILL }},

		{ &hf_g_pmu_id,
		{ "Global PMU ID (raw hex bytes)", "synphasor.gpmuid", FT_BYTES, BASE_NONE,
		  NULL, 0x0, NULL, HFILL }},

		{ &hf_soc,
		{ "SOC time stamp", "synphasor.soc", FT_ABSOLUTE_TIME, ABSOLUTE_TIME_UTC,
		  NULL, 0x0, NULL, HFILL }},

		/* Time quality flags in fracsec */
		{ &hf_timeqal_lsdir,
		{ "Leap second direction", "synphasor.timeqal.lsdir", FT_BOOLEAN, 8,
		  TFS(&leapseconddir), 0x40, NULL, HFILL }},

		{ &hf_timeqal_lsocc,
		{ "Leap second occurred", "synphasor.timeqal.lsocc", FT_BOOLEAN, 8,
		  NULL, 0x20, NULL, HFILL }},

		{ &hf_timeqal_lspend,
		{ "Leap second pending", "synphasor.timeqal.lspend", FT_BOOLEAN, 8,
		  NULL, 0x10, NULL, HFILL }},

		{ &hf_timeqal_timequalindic,
		{ "Message Time Quality indicator code", "synphasor.timeqal.timequalindic", FT_UINT8, BASE_HEX,
		  VALS(timequalcodes), 0x0F, NULL, HFILL }},

		/* Fraction of second */
		{ &hf_fracsec_raw,
		{ "Fraction of second (raw)", "synphasor.fracsec_raw", FT_UINT24, BASE_DEC,
		  NULL, 0x0, NULL, HFILL }},

		{ &hf_fracsec_ms,
		{ "Fraction of second", "synphasor.fracsec_ms", FT_FLOAT, BASE_NONE | BASE_UNIT_STRING,
		  UNS(&units_millisecond_milliseconds), 0x0, NULL, HFILL }},

	/* Data types for configuration frames */
		{ &hf_cont_idx,
		{ "Continuation index", "synphasor.conf.contindx", FT_UINT16, BASE_DEC,
		  NULL, 0x0, NULL, HFILL }},

		{ &hf_conf_timebase,
		{ "Resolution of fractional second time stamp", "synphasor.conf.timebase", FT_UINT24, BASE_DEC,
		  NULL, 0x0, NULL, HFILL }},

		{ &hf_conf_numpmu,
		{ "Number of PMU blocks included in the frame", "synphasor.conf.numpmu", FT_UINT16, BASE_DEC,
		  NULL, 0x0, NULL, HFILL }},

		/* Bits in the FORMAT word */
		{ &hf_conf_formatb3,
		{ "FREQ/DFREQ format", "synphasor.conf.dfreq_format", FT_BOOLEAN, 16,
		  TFS(&conf_formatb123names), 0x8, NULL, HFILL }},

		{ &hf_conf_formatb2,
		{ "Analog values format", "synphasor.conf.analog_format", FT_BOOLEAN, 16,
		  TFS(&conf_formatb123names), 0x4, NULL, HFILL }},

		{ &hf_conf_formatb1,
		{ "Phasor format", "synphasor.conf.phasor_format", FT_BOOLEAN, 16,
		  TFS(&conf_formatb123names), 0x2, NULL, HFILL }},

		{ &hf_conf_formatb0,
		{ "Phasor notation", "synphasor.conf.phasor_notation", FT_BOOLEAN, 16,
		  TFS(&conf_formatb0names), 0x1, NULL, HFILL }},

		{ &hf_conf_chnam_len,
		{ "Channel name length", "synphasor.conf.chnam_len", FT_UINT8,
		  BASE_DEC | BASE_UNIT_STRING, UNS(&units_byte_bytes), 0x0, NULL, HFILL }},

		{ &hf_conf_chnam,
		{ "Channel name", "synphasor.conf.chnam", FT_STRING, BASE_NONE,
		  NULL, 0x0, NULL, HFILL }},

		{ &hf_conf_phasor_mod_b15,
		{ "Modification", "synphasor.conf.phasor_mod.type_not_def", FT_BOOLEAN, 16,
		  TFS(&conf_phasor_mod_b15), 0x8000, NULL, HFILL }},

		{ &hf_conf_phasor_mod_b10,
		{ "Modification", "synphasor.conf.phasor_mod.pseudo_phasor", FT_BOOLEAN, 16,
		  TFS(&conf_phasor_mod_b10), 0x0400, NULL, HFILL }},

		{ &hf_conf_phasor_mod_b09,
		{ "Modification", "synphasor.conf.phasor_mod.phase_rotation", FT_BOOLEAN, 16,
		  TFS(&conf_phasor_mod_b09), 0x0200, NULL, HFILL }},

		{ &hf_conf_phasor_mod_b08,
		{ "Modification", "synphasor.conf.phasor_mod.phase_calibration", FT_BOOLEAN, 16,
		  TFS(&conf_phasor_mod_b08), 0x0100, NULL, HFILL }},

		{ &hf_conf_phasor_mod_b07,
		{ "Modification", "synphasor.conf.phasor_mod.mag_calibration", FT_BOOLEAN, 16,
		  TFS(&conf_phasor_mod_b07), 0x0080, NULL, HFILL }},

		{ &hf_conf_phasor_mod_b06,
		{ "Modification", "synphasor.conf.phasor_mod.filtered", FT_BOOLEAN, 16,
		  TFS(&conf_phasor_mod_b06), 0x0040, NULL, HFILL }},

		{ &hf_conf_phasor_mod_b05,
		{ "Modification", "synphasor.conf.phasor_mod.downsampled", FT_BOOLEAN, 16,
		  TFS(&conf_phasor_mod_b05), 0x0020, NULL, HFILL }},

		{ &hf_conf_phasor_mod_b04,
		{ "Modification", "synphasor.conf.phasor_mod.downsampled_fir", FT_BOOLEAN, 16,
		  TFS(&conf_phasor_mod_b04), 0x0010, NULL, HFILL }},

		{ &hf_conf_phasor_mod_b03,
		{ "Modification", "synphasor.conf.phasor_mod.downsampled_reselect", FT_BOOLEAN, 16,
		  TFS(&conf_phasor_mod_b03), 0x0008, NULL, HFILL }},

		{ &hf_conf_phasor_mod_b02,
		{ "Modification", "synphasor.conf.phasor_mod.upsampled_extrapolation", FT_BOOLEAN, 16,
		  TFS(&conf_phasor_mod_b02), 0x0004, NULL, HFILL }},

		{ &hf_conf_phasor_mod_b01,
		{ "Modification", "synphasor.conf.phasor_mod.upsampled_interpolation", FT_BOOLEAN, 16,
		  TFS(&conf_phasor_mod_b01), 0x0002, NULL, HFILL }},

		{ &hf_conf_phasor_type_b03,
		{ "Phasor Type", "synphasor.conf.phasor_type", FT_BOOLEAN, 8,
		  TFS(&conf_phasor_type_b03), 0x8, NULL, HFILL }},

		{ &hf_conf_phasor_type_b02to00,
		{ "Phasor Type", "synphasor.conf.phasor_component", FT_UINT8, BASE_HEX,
		  VALS(conf_phasor_type_b02to00), 0x7, NULL, HFILL }},

		{ &hf_conf_phasor_user_data,
		{ "Binary format", "synphasor.conf.phasor_user_flags", FT_BOOLEAN, 8,
		  TFS(&conf_phasor_user_defined), 0xff, NULL, HFILL }},

		{ &hf_conf_phasor_scale_factor,
		{ "Phasor scale factor", "synphasor.conf.phasor_scale_factor", FT_FLOAT,
		  BASE_NONE, NULL, 0x0, NULL, HFILL }},

		{ &hf_conf_phasor_angle_offset,
		{ "Phasor angle offset", "synphasor.conf.phasor_angle_offset", FT_FLOAT,
		  BASE_NONE | BASE_UNIT_STRING, UNS(&units_degree_degrees), 0x0, NULL, HFILL }},

		{ &hf_conf_analog_scale_factor,
		{ "Analog scale factor", "synphasor.conf.analog_scale_factor", FT_FLOAT,
		  BASE_NONE, NULL, 0x0, NULL, HFILL }},

		{ &hf_conf_analog_offset,
		{ "Analog offset", "synphasor.conf.analog_offset", FT_FLOAT,
		  BASE_NONE, NULL, 0x0, NULL, HFILL }},

		{ &hf_conf_pmu_lat,
		{ "PMU Latitude", "synphasor.conf.pmu_latitude", FT_FLOAT,
		  BASE_NONE | BASE_UNIT_STRING, UNS(&units_degree_degrees), 0x0, NULL, HFILL }},

		{ &hf_conf_pmu_lon,
		{ "PMU Longitude", "synphasor.conf.pmu_longitude", FT_FLOAT,
		  BASE_NONE | BASE_UNIT_STRING, UNS(&units_degree_degrees), 0x0, NULL, HFILL }},

		{ &hf_conf_pmu_elev,
		{ "PMU Elevation", "synphasor.conf.pmu_elevation", FT_FLOAT,
		  BASE_NONE | BASE_UNIT_STRING, UNS(&units_meter_meters), 0x0, NULL, HFILL }},

		{ &hf_conf_pmu_lat_unknown,
		{ "PMU Latitude", "synphasor.conf.pmu_latitude", FT_FLOAT, BASE_NONE,
		  NULL, 0x0, NULL, HFILL }},

		{ &hf_conf_pmu_lon_unknown,
		{ "PMU Longitude", "synphasor.conf.pmu_longitude", FT_FLOAT, BASE_NONE,
		  NULL, 0x0, NULL, HFILL }},

		{ &hf_conf_pmu_elev_unknown,
		{ "PMU Elevation", "synphasor.conf.pmu_elevation", FT_FLOAT, BASE_NONE,
		  NULL, 0x0, NULL, HFILL }},

		{ &hf_conf_svc_class,
		{ "Service class", "synphasor.conf.svc_class", FT_STRING, BASE_NONE,
		  NULL, 0x0, NULL, HFILL }},

		{ &hf_conf_window,
		{ "PM window length", "synphasor.conf.window", FT_UINT32,
		  BASE_DEC | BASE_UNIT_STRING, UNS(&units_microsecond_microseconds), 0x0, NULL, HFILL }},

		{ &hf_conf_grp_dly,
		{ "PM group delay", "synphasor.conf.grp_dly", FT_UINT32,
		  BASE_DEC | BASE_UNIT_STRING, UNS(&units_microsecond_microseconds), 0x0, NULL, HFILL }},

		{ &hf_conf_fnom,
		{ "Nominal line frequency", "synphasor.conf.fnom", FT_BOOLEAN, 16,
		  TFS(&conf_fnomnames), 0x0001, NULL, HFILL }},

		{ &hf_conf_cfgcnt,
		{ "Configuration change count", "synphasor.conf.cfgcnt", FT_UINT16, BASE_DEC,
		  NULL, 0, NULL, HFILL }},

	/* Data types for data frames */
		/* Link to CFG Frame */
		{ &hf_cfg_frame_num,
		{ "Dissected using configuration from frame", "synphasor.data.conf_frame", FT_FRAMENUM, BASE_NONE, NULL, 0x0,"", HFILL }},

		/* Flags in the STAT word */
		{ &hf_data_statb15to14,
		{ "Data error", "synphasor.data.status", FT_UINT16, BASE_HEX,
		  VALS(data_statb15to14names), 0xC000, NULL, HFILL }},

		{ &hf_data_statb13,
		{ "Time synchronized", "synphasor.data.sync", FT_BOOLEAN, 16,
		  TFS(&data_statb13names), 0x2000, NULL, HFILL }},

		{ &hf_data_statb12,
		{ "Data sorting", "synphasor.data.sorting", FT_BOOLEAN, 16,
		  TFS(&data_statb12names), 0x1000, NULL, HFILL }},

		{ &hf_data_statb11,
		{ "Trigger detected", "synphasor.data.trigger", FT_BOOLEAN, 16,
		  TFS(&data_statb11names), 0x0800, NULL, HFILL }},

		{ &hf_data_statb10,
		{ "Configuration changed", "synphasor.data.CFGchange", FT_BOOLEAN, 16,
		  TFS(&data_statb10names), 0x0400, NULL, HFILL }},

		{ &hf_data_statb09,
		{ "Data modified indicator", "synphasor.data.data_modified", FT_BOOLEAN, 16,
		  TFS(&data_statb09names), 0x0200, NULL, HFILL }},

		{ &hf_data_statb08to06,
		{ "PMU Time Quality", "synphasor.data.pmu_tq", FT_UINT16, BASE_HEX,
		  VALS(data_statb08to06names), 0x01C0, NULL, HFILL }},

		{ &hf_data_statb05to04,
		{ "Unlocked time", "synphasor.data.t_unlock", FT_UINT16, BASE_HEX,
		  VALS(data_statb05to04names), 0x0030, NULL, HFILL }},

		{ &hf_data_statb03to00,
		{ "Trigger reason", "synphasor.data.trigger_reason", FT_UINT16, BASE_HEX,
		  VALS(data_statb03to00names), 0x000F, NULL, HFILL }},

	/* Data type for command frame */
		{ &hf_command,
		{ "Command", "synphasor.command", FT_UINT16, BASE_HEX|BASE_RANGE_STRING,
		  RVALS(command_names), 0x0, NULL, HFILL }},

      /* Generated from convert_proto_tree_add_text.pl */
      { &hf_synphasor_data, { "Data", "synphasor.data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
      { &hf_synphasor_checksum, { "Checksum", "synphasor.checksum", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }},
      { &hf_synphasor_checksum_status, { "Checksum Status", "synphasor.checksum.status", FT_UINT8, BASE_NONE, VALS(proto_checksum_vals), 0x0, NULL, HFILL }},
      { &hf_synphasor_num_phasors, { "Number of phasors", "synphasor.num_phasors", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
      { &hf_synphasor_num_analog_values, { "Number of analog values", "synphasor.num_analog_values", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
      { &hf_synphasor_num_digital_status_words, { "Number of digital status words", "synphasor.num_digital_status_words", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
      { &hf_synphasor_rate_of_transmission, { "Rate of transmission", "synphasor.rate_of_transmission", FT_INT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
      { &hf_synphasor_phasor, { "Phasor", "synphasor.phasor", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
      { &hf_synphasor_actual_frequency_value, { "Actual frequency value", "synphasor.actual_frequency_value", FT_FLOAT, BASE_NONE|BASE_UNIT_STRING, UNS(&units_hz), 0x0, NULL, HFILL }},
      { &hf_synphasor_rate_change_frequency, { "Rate of change of frequency", "synphasor.rate_change_frequency", FT_FLOAT, BASE_NONE|BASE_UNIT_STRING, UNS(&units_hz_s), 0x0, NULL, HFILL }},
      { &hf_synphasor_frequency_deviation_from_nominal, { "Frequency deviation from nominal", "synphasor.frequency_deviation_from_nominal", FT_INT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
      { &hf_synphasor_analog_value, { "Analog value", "synphasor.analog_value", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
      { &hf_synphasor_digital_status_word, { "Digital status word", "synphasor.digital_status_word", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }},
      { &hf_synphasor_conversion_factor, { "conversion factor", "synphasor.conversion_factor", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }},
      { &hf_synphasor_factor_for_analog_value, { "Factor for analog value", "synphasor.factor_for_analog_value", FT_UINT32, BASE_DEC, NULL, 0x000000FF, NULL, HFILL }},
      { &hf_synphasor_channel_name, { "Channel name", "synphasor.channel_name", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
      { &hf_synphasor_extended_frame_data, { "Extended frame data", "synphasor.extended_frame_data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
      { &hf_synphasor_unknown_data, { "Unknown data", "synphasor.data.unknown", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
      { &hf_synphasor_status_word_mask_normal_state, { "Normal state", "synphasor.status_word_mask.normal_state", FT_UINT16, BASE_HEX, NULL, 0xFFFF, NULL, HFILL }},
      { &hf_synphasor_status_word_mask_valid_bits, { "Valid bits", "synphasor.status_word_mask.valid_bits", FT_UINT16, BASE_HEX, NULL, 0xFFFF, NULL, HFILL }},
	};

	/* protocol subtree array */
	static int *ett[] = {
		&ett_synphasor,
		&ett_frtype,
		&ett_timequal,
		&ett_conf,
		&ett_conf_station,
		&ett_conf_format,
		&ett_conf_phnam,
		&ett_conf_annam,
		&ett_conf_dgnam,
		&ett_conf_phconv,
		&ett_conf_phlist,
		&ett_conf_phflags,
		&ett_conf_phmod_flags,
		&ett_conf_ph_user_flags,
		&ett_conf_anconv,
		&ett_conf_anlist,
		&ett_conf_dgmask,
		&ett_conf_chnam,
		&ett_conf_wgs84,
		&ett_data,
		&ett_data_block,
		&ett_data_stat,
		&ett_data_phasors,
		&ett_data_analog,
		&ett_data_digital,
		&ett_command,
		&ett_status_word_mask
	};

	static ei_register_info ei[] = {
		{ &ei_synphasor_extended_frame_data, { "synphasor.extended_frame_data.unaligned", PI_PROTOCOL, PI_WARN, "Size not multiple of 16-bit word", EXPFILL }},
		{ &ei_synphasor_checksum, { "synphasor.bad_checksum", PI_CHECKSUM, PI_ERROR, "Bad checksum", EXPFILL }},
		{ &ei_synphasor_data_error, { "synphasor.data_error", PI_RESPONSE_CODE, PI_NOTE, "Data Error flag set", EXPFILL }},
		{ &ei_synphasor_pmu_not_sync, { "synphasor.pmu_not_sync", PI_RESPONSE_CODE, PI_NOTE, "PMU not sync flag set", EXPFILL }},
	};

	expert_module_t* expert_synphasor;

	/* register protocol */
	proto_synphasor = proto_register_protocol(PNAME, PSNAME, PFNAME);

	/* Registering protocol to be called by another dissector */
	synphasor_udp_handle = register_dissector("synphasor", dissect_udp, proto_synphasor);
	synphasor_tcp_handle = register_dissector("synphasor.tcp", dissect_tcp, proto_synphasor);

	proto_register_field_array(proto_synphasor, hf, array_length(hf));
	proto_register_subtree_array(ett, array_length(ett));
	expert_synphasor = expert_register_protocol(proto_synphasor);
	expert_register_field_array(expert_synphasor, ei, array_length(ei));

} /* proto_register_synphasor() */

/* called at startup and when the preferences change */
void proto_reg_handoff_synphasor(void)
{
	dissector_add_for_decode_as("rtacser.data", synphasor_udp_handle);
	dissector_add_uint_with_preference("udp.port", SYNPHASOR_UDP_PORT, synphasor_udp_handle);
	dissector_add_uint_with_preference("tcp.port", SYNPHASOR_TCP_PORT, synphasor_tcp_handle);
} /* proto_reg_handoff_synphasor() */

/*
 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 8
 * tab-width: 8
 * indent-tabs-mode: t
 * End:
 *
 * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 * :indentSize=8:tabSize=8:noTabs=false:
 */