diff --git a/docs/dvl/dvl-triggering.md b/docs/dvl/dvl-triggering.md index cef87dbb..3122186e 100644 --- a/docs/dvl/dvl-triggering.md +++ b/docs/dvl/dvl-triggering.md @@ -9,16 +9,19 @@ The DVL has different options for triggering acoustic pings to perform a velocit ## Hardware triggering -Use the RS232 RX line of the DVL to send a trigger command after enabling hardware triggering in the [configuration](configuration.md#operating-configurations). +Use the RS232 RX line of the DVL to trigger a ping after enabling hardware triggering in the [configuration](configuration.md#operating-configurations). -Once hardware triggering is enabled, transmit a "NUL" ASCII character (Ctrl + @) to send a ping. The trigger is detected on the falling edge of the signal. +The trigger is detected on the falling edge of the RX signal. The signal must then remain low for approximately 78.1 µs before returning high. - +For a connection configured as 115200 baud, 8N1, this pulse corresponds to transmitting a `"NUL"` ASCII character (`0x00`, Ctrl + @). -You can send this trigger signal as often as needed. If the DVL is already transmitting, it discards the signal. +Because the trigger is defined by its pulse timing, sending a `NUL` character at another baud rate may **not** produce a valid trigger. + +The trigger can be sent as often as needed. If the DVL is already transmitting or receiving, incoming trigger signals are discarded. !!! warning - Acoustics must be enabled. If acoustics are disabled, hardware triggering will not work. + + Acoustics must be enabled. Hardware triggering will not work while acoustics are disabled. ## Software triggering