ni-3100 I/O sticking

alexsquared

Just got a service call from a customer. They have a system where the ni3100 has door position sensors connected to the i/o ports to give info on partiton status. It is. Large conference/ballroom that can be broken up into 5 small rooms. We just replaced both ni units as they were having the issue with the rs232 capacitors. Now we have an issue (only happened once so far) where regardless of the sensor state, the controller things the i/o I closed. The only thing they could do that clearedit was pull power to the NI. Once it powere up again, it reflected the correct state. I have only seen this once before at a different site. Has any one else seen this? Any thoughts on a soluton other then hardware replacement?

TurnipTruck

Did you try pulling the I/O connection to see if the state opened?

If the I/O state is erroriously closed (LED on) the problem could be numerous things outside of the controller.

DHawthorne

I wonder if it isn't a feedback channel vs. output thing. I've only heard of it happening with relay devices used in a mutually exclusive definition, but there are conditions that can un-sync the two so that the channel feedback doesn't match the actual output of the device.

alexsquared

TurnipTruck wrote: »

Did you try pulling the I/O connection to see if the state opened?

If the I/O state is erroriously closed (LED on) the problem could be numerous things outside of the controller.

Yes, the terminal strip for the I/O's was pulled to no avail. Only thing that cleared it was cycling power. M< WE USED THE AMX power sensing boxes s problem, we used the AMX power sensing boxes (PCS2) to monitor the TV power status. These then feed to the I/O of their NI for discrete control. Same thing...I/O's stuck in the on state. I had to unplug that unit as well for it to clear. I only had it happen on time at that site and this is the first time now at a second site. Makes me a little hesitant to bank on the I/O ports as reliable. I got grilled pretty hard by the customer yesterday as they had a conference using two of the partitioned rooms, but could only get one to work until the unit reset.

DHawthorne

If your ports are unreliable, it's an equipment failure, not an indication you can't depend on the I/O ports in general. I have personally never had them fail like you are describing.

You might want to look at the power consumption on your 12v line coming out of the controller too ... I/O ports are TTL driven, and if something is pulling the buss voltage down too far, it could make them read falsely. I had a similar thing happen to me (not on an AMX controller, but the concept is the same) where I was getting all sorts of false sensor reading, and it turned out the voltage regulator feeding them had failed, and they were getting too much voltage, resulting fluctuations the sensor interpreted as a positive when no such event was happening.

duncanwall

Thanks for this, i've been having intermittent problems with my I/o's for some time now. After reading this I checked my power supply, which was read way over voltage! Replaced it all seems well.