September
2017
Sentinel V SC and RT Operation Manual
Page 38
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Using the Trigger
The Sentinel V Real-time has the ability to be triggered or to send triggers in order to synchronize pings or
ensembles to external signals. Only the RS-232 configuration has wiring to allow both Trigger-in and
Trigger-out. The Sentinel V Real-Time RS-422 and Ethernet configurations do not have trigger capability.
The trigger signal uses 3.3V TTL Logic levels for trigger-in/out across the external trigger pins (see Figure
32 page 82 for wiring). The valid logic levels are <0.7V for LOW and 2.0V to 3.3V for HIGH.
Pulse signals
should be between 10ms and 40ms long, but ideally 20-30ms.
The Sync/Trigger Commands SA, SM, and ST commands control triggering.
•
SM2 command must be sent first to turn on triggering. SM2 enables the SA and ST commands.
•
ST sets the amount of time the ADCP will wait to hear a synch pulse before proceeding on its
own (default 60 seconds). If the ADCP times out, it will automatically ping according to the CF,
TP, TE, WP, and BP command settings. This is a fail-safe mechanism designed to allow the
ADCP to proceed on its own should communications with the synch pulse fail. Setting ST to zero
tells the ADCP to wait indefinitely.
•
SA command controls when the ADCP pings.
Command
Description
SA00
Send (wait for) pulse before a ping.
SA01
Send (wait for) pulse before ensemble.
To send the trigger commands:
1. Use Sentinel V RT Utilities to connect to the ADCP. Click Start.
2. Use the Wizard or open a *.plan file. Use the Command tab to enter the S commands into the
Custom Commands box.
3. Click Deploy.
