How can I program a repetitive BC external trigger input using BusTools/1553 API? I want the BC to wait for an external trigger to start each minor frame.

This is a basic example program that sets up a simple BC message list. This program is just a modification of "example_bc1.c" that adds the repetitive external trigger. A BC list is provided with of two messages, 1-R-1-32 and 2-T-2-32, in a 20ms Minor Frame. This BC list runs until stopped by user input. You can display the data for the 2-T-2-32 message or quit.

The Minor Frame time is meaningless in this case because the BC stops to wait for an external trigger on each frame.

The BC message list consists of two messages and a BC STOP block. This causes the BC to stop executing until the next external trigger input signal is detected, then the process repeats.

This example has been tested with trigger frequencies up to 500Hz.