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SWITCH DATA COMMAND (con't)
The following External Trigger Control byte is valid only for 852 Echo Sounders
supplied with the External Trigger Hardware Option. The external trigger must be
a 0 to 5 volt TTL pulse with a minimum length of 100 microseconds.
Byte 18
External Trigger Control
Bit0: Trigger Edge: 0 = NEG, 1 = POS
Bit1: Trigger Enable: 0 = Disable, 1 = Enable
Bit 2: Trigger Mode:
0 = Manual
- in manual mode, the unit must be "armed" every ping by sending
a Switch Data Command with Trigger Enable= 1. When a valid
trigger pulse is detected, the echo sounder will transmit, send
data (if Send Data in Byte 6 = 1), then wait for the next Switch
Data Command. If a trigger pulse is not detected within 100
milliseconds of being armed, the unit will transmit as normal then
wait for the next Switch Data Command.
1 = Automatic
- in automatic mode, the unit is "armed" with a single Switch Data
Command (with Trigger Enable = 1). When a valid trigger pulse is
detected, the echo sounder will transmit, send data (if Send Data in
Byte 6 = 1) and then automatically re-arm itself and wait for the
next trigger pulse. A Switch Data Command can be sent at any
time to change parameters such as range, gain, pulse length, etc.
Byte 19
Data Points
25
- 250 data points are returned by the echo sounder
The return data will have an ASCII '
IMX
' header.
50
- 500 data points are returned by the echo sounder
The return data will have an ASCII '
IGX
' header.
Byte 20
Reserved
Always 0
Byte 21
Reserved
Always 0
Byte 22
Profile
0 = OFF
1 = ON --> The return data will have an ASCII '
IPX
' header.
