User`s manual

DATA STORAGE FILE FORMAT (.81S) (con't)
Page 13 of 13
Data Bytes High Byte = (Byte 111 & 0x7E)>>1
Data Bytes Low Byte = [((Byte 111 & 0x01)<<7) | (Byte 110 & 0x7F)]
Data Bytes = (Data Bytes High Byte<<8) | Data Bytes Low Byte
Number of echo data bytes = Data Bytes - 12
SONAR RETURN ECHO DATA
Bytes 112 through 511 contain the following Sonar Return Echo Data information:
If Byte 106 = 1 (Stbd) or 2 (Port), there are 400 range bytes starting at range 0 (Byte
112), ending at range 399 (Byte 511)
If Byte 106 = 3 (Both), there are 200 range bytes per channel. The range bytes alternate
from channel to channel.
i.e.
Stbd[0] = Byte 112
Port[0] = Byte 113
Stbd[ 1 ] = Byte 114
Port[1] = Byte 115 .
.
Stbd[ 199] = Byte 510
Port[199] = Byte 511
The sonar data intensity level varies from 0 to 127.
Byte 512 Termination Byte - always 0xFC
B
y
te 110 B
y
te 111
7
6
7
6
0
0 Data Bytes (LO) 0 Data Bytes (HI) L
110 - 111 Data Bytes
Number of Data Bytes returned from the SportScan head (including
the Data Header, but not including the termination byte) Data Bytes
(LO), Data Bytes (HI)