g.mccormick
Lifetime Supporting Member
I ran into a strange issue the other day. System has been up and running for many months.
An analog input channel suddenly reported 0mA. I investigated assuming dead transmitter, wiring failure, etc.
I found that the transmitter was working and there was indeed a signal on the wire. The module lights for all 4 channels were red. I went on-line and the module status said NONE for major or minor faults. Also the module shows configured and Running.
The 4 channels on the module all had a status of 0 and the value for the channel was 0 for channel 0 (where transmitter is wired). I tested all 4 channels with a source and they all showed nothing.
Next, I changed the setting for one of the channels from 0-20ma to 0-10V and when I did, all of the channels starting working again. I was able to set the changed channel back to 0-20ma and everything stayed working. I found one other module that had the exact same behavior. It has all 4 channels as spares (the first effected module had one channel in use). I again had to change the configuration of a channel to get all of the channels reading again.
Neither module showed anything for faults, and both showed .RunMode = true.
Has anyone ran into this before?
An analog input channel suddenly reported 0mA. I investigated assuming dead transmitter, wiring failure, etc.
I found that the transmitter was working and there was indeed a signal on the wire. The module lights for all 4 channels were red. I went on-line and the module status said NONE for major or minor faults. Also the module shows configured and Running.
The 4 channels on the module all had a status of 0 and the value for the channel was 0 for channel 0 (where transmitter is wired). I tested all 4 channels with a source and they all showed nothing.
Next, I changed the setting for one of the channels from 0-20ma to 0-10V and when I did, all of the channels starting working again. I was able to set the changed channel back to 0-20ma and everything stayed working. I found one other module that had the exact same behavior. It has all 4 channels as spares (the first effected module had one channel in use). I again had to change the configuration of a channel to get all of the channels reading again.
Neither module showed anything for faults, and both showed .RunMode = true.
Has anyone ran into this before?