External recording triggers

2 min read · updated 23 Jul 2026

External triggers allow studio equipment, automation systems, control surfaces or a small microcontroller to start and stop BroadcastLogger without an operator selecting Record.

Configure one trigger method at a time, confirm the correct device or port, then perform a short supervised test before relying on it for unattended recording.

Trigger methodBest suited to
Serial text commandAutomation systems and Arduino-style controllers that can send defined start and stop text over a COM port.
MIDI note or control changeMIDI-capable studio consoles, button panels and class-compliant USB MIDI controllers.
Serial contact closureA relay, opto-isolated interface or supported serial adapter that presents a hardware sense-line state such as CTS.
Run-onKeeps recording active for the selected period after the stop condition is received, preventing the end of audio from being clipped.

TEST FIRST: External triggers can start recording unexpectedly if the wrong COM port, MIDI channel, note number or sense line is selected. Test with a temporary output folder and watch the event log while commissioning the trigger.

Commissioning an external trigger

  1. Select the trigger method, port or MIDI device and matching settings.
  2. Choose a temporary output folder and confirm that normal manual recording works.
  3. Activate the external trigger and verify that REC appears and the elapsed timer advances.
  4. Release or stop the trigger. Confirm that recording continues for the configured run-on period and then closes cleanly.
  5. Open Archive, play the test file and confirm that both the beginning and end of the required audio are present.
  6. Restart BroadcastLogger and the external device, then repeat the test to confirm reliable reconnection.

Quick trigger troubleshooting

SymptomChecks
COM port is missingReconnect the interface, check Windows Device Manager, then reopen Settings. The COM number may change when a device is moved to another USB socket.
Serial commands are ignoredMatch the baud rate and command text exactly. Close serial monitors or other programs that may already be using the port.
MIDI device is not listedConnect and power the MIDI device before starting BroadcastLogger. Confirm that Windows recognises it and try channel any while testing.
Trigger starts but does not stopCheck the stop command, Note Off or zero-value message, or the contact sense state. Reduce Run-on during testing and try Invert for contact closure.

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