I have a test environment employing an NCD PR-16-9-10A relay board with an attached Particle Boron. The environment is an exact replica of a production system. I have been using this setup to test firmware modifications before uploading them to the production system.
My firmware reads the status of and controls relay #2 only. There never was and there still is no reference whatsoever to relay #1. Yet I just noticed, by chance, that relay #1 closed, as indicated by its audible click and its associated red LED. Has anyone ever heard of such behavior and, if so, what in the world would cause it?
To make sure that if it happens again, the firmware will turn it back off (open it back up), I added the following two lines of code in the loop:
if (controller.readRelayStatus (1) == 1){ // If relay #1 is closed
controller.turnOffRelay(1); // Open relay #1
}
That will make sure that it won’t happen again (although, since relay #1 isn’t wired to anything, it wouldnt be a problem anyway). But I am curious as to what might be going on. I want to make sure that random operation of relay #2 doesn’'t occur.