Output datagrams
3.2.2 XYZ 88
Note
This datagram replaces the previous depth (D) datagram for the
new multibeam models (EM 2040, EM 710, EM 122, EM 302,
ME 70). All receiver beams are included, check detection info
and real time cleaning for beam status (note 4 and 5).
Table 24
XYZ 88
Data Description
Format
Valid range
Note
Number of bytes in datagram
4U
—
—
Start identifier = STX (Always 02h)
1U
—
—
Type of datagram = X (58h, 88d)
1U
—
—
EM model number (Example: EM 710 = 710)
2U
—
—
Date = year*10000 + month*100 + day (Example:
Sep 26, 2005 = 20050926)
4U
—
—
Time since midnight in milliseconds
(Example: 08:12:51.234 = 29570234)
4U
0 to 86399999
—
Ping counter (sequential counter)
2U
0 to 65535
—
System serial number
2U
100 –
—
Heading of vessel (at TX time) in 0.01°
2U
0 to 35999
—
Sound speed at transducer in dm/s
2U
14000 to 16000
—
Transmit transducer depth in m re water level at
time of ping
4F
—
1
Number of beams in datagram = N
2U
1 – 1024
—
Number of valid detections
2U
1 – 1024
—
Sampling frequency in Hz
4F
—
—
Spare
4S
—
—
Repeat cycle - N entries of :
20*N
–
–
Depth (z) from transmit transducer in m
4F
—
2
Acrosstrack distance (y) in m
4F
—
2
Alongtrack distance (x) in m
4F
—
2
Detection window length in samples
2U
—
—
Quality factor
1U
0 – 254
3
Beam incidence angle adjustment (IBA) in 0.1 deg 1S
-128 to 126
6
Detection information
1U
—
4
Real time cleaning information
1S
—
5
Reflectivity (BS) in 0.1 dB resolution
(Example: –20.1 dB = FF37h= 65335)
2S
—
—
End of repeat cycle
Spare (always 0)
1U
0
—
End identifier = ETX (Always 03h)
1U
—
—
Check sum of data between STX and ETX
2U
—
—
850-160692/M
47