Simrad EY500, Instruction Manual

Page: 155 / 262

Description of telegrams and remote control
P3404E/A
15
struct Echogram { /* echogram (post processor) */
char Header[2]; /* "Q1" */
char Separator1[1]; /* "," */
char Time[8]; /* hour, minute, second, hundredth */
char Separator2[1]; /* "," */
long TVGType; /* TVG type: */
float Depth; /* detected bottom depth [meter] */
float PelagicUpper; /* upper depth of pelagic echogram [meter] */
float PelagicLower; /* lower depth of pelagic echogram [meter] */
long PelagicCount;
/* number of pelagic echogram data points */
float BottomUpper; /* upper depth of bottom echogram [meter] */
float BottomLower; /* lower depth of bottom echogram [meter] */
long BottomCount; /* number of bottom echogram data points */
short Data[1200]; /* max 1200 bottom echogram data points */
};
The resolution of the pelagic echogram and the bottom echogram is controlled
by parameters in the Disk Menu. The TVG type indicates which TVG is used (0
= 20 log R, S
v
, 1 = 40 log R, TS). Depth and range parameters are output in
meter. The size of the pelagic echogram array and bottom echogram array are
included. The S
v
/TS data is output in the EY 500 dB format (Refer to section
"Theory of Operation", chapter 3, "EY 500 dB format").
struct Sample { /* sample angle data */
char Header[2]; /* "B1" */
char Separator1[1]; /* "," */
char Time[8]; /* hour, minute, second, hundredth */
char Separator2[1]; /* "," */
short Data[5000]; /* max 5000 data points per data block*/
};
The B1 output telegram provides angle sample data from the transceiver
(applies to split beam transducer channel only) and is used for special purpose
studies. The fore-and-aft (alongship) and athwartships electrical angles are
output as one 16-bit word; the alongship angle as the most significant byte and
the athwartships angle as the least significant byte. Angle data is output in
units of phase steps (64 phase steps = 180 electrical degrees) where the least
significant seven bits are the magnitude and the most significant bit is the sign;
zero in the fore and starboard direction, one in the aft and port direction. Thus,
an angle is not expressed in 2’s complement. The sample data limits are given
by the sample range in the Disk Menu/Telegram Menu.