I first had triggers set for contact closure, and at first Edge type, but got a random unwanted trigger, so I changed the trigger type to Level, but still got a random trigger days later. Furthermore, I didn’t think Level type would allow the track to maintain playing, even if randomly trigger, but it did, so I’m guessing Level only applies to an Active 3.3V interface. My application cannot allow for random triggers.
Solution 1: use shielded wire for triggers, with shield connected to earth ground.
Solution 2: use Arduino/serial to generate trigger
Solution 3: use Active 3.3 hardware interface with Level type selected.
Which would be considered the most robust option to prevent false triggers?
My inputs are coming from an industrial PLC, which is currently controlling relays to provide contact closure for the Super WAV inputs. If option one is viable, to replace single solid wire conductors with shielded cables, to eliminate any chance of random triggers, I can do this easiest.
I lack any familiarity with Arduino, so am reluctant to interface with this as an option, but will pursue it if this is the highest reliability option.
I am also considering option 3, if I could use something like this:
https://www.amazon.com/8-Channel-Photoe … B07VMFMZFH
Is this a robust option to change the hardware interface to Active and Type to Level?
Unwanted random starts are almost always caused by noise on the trigger inputs. How long are the lines between the PLC and the Tsunami?
If you can allow for it in your PLC programming, using level triggered mode should partially mask the problem, although if you have noise while the track is playing, noise could cause it to re-trigger from the beginning. You could also disable re-triggering. I have no explanation as to why you had a constantly playing track in level mode when the input was low. That should not happen. In any event, noise large enough to cause any triggering is not good.
Do you have anything going on that might generate spikes on the power supply or in the air (electromagnetic radiation)?
If you can’t shorten the wires, the first thing I might try is a stronger pullup resistor at the Tsunami input, say 10K
Thank you for your reply. It turns out that the Level selection that I had made was turned back off for two of the six inputs that I am using. That is because those two tracks require to be in loop mode, which logically isn’t necessary for Level - however it does make them susceptible to RFI, which is most likely what caused my very unfortunate trigger.
I believe that my best option will be to use Contact Closure, but with Invert selected, and then have my logic to hold the trigger low until commanded to play. This should mostly eliminate RFI problem, would it not? Furthermore, I will place the Super WAV inside a SS enclosure to shield it, and use grounded shield cables for my triggers. Hopefully this extra precaution will provide more than enough protection from stray triggers.
FYI, I am designing this for a mass notification system with 5 different WAV files, and one input for a STOP command. It may be unnecessary overkill, but I’m also considering maintaining a STOP input, only removing it on command for any selected broadcast.