I am using an SM 421 Analog Output Module (432-1HF00-0AB0) and have noticed that CH1 and CH2 output significantly different values than they should. Rather than 0 - 27648: 4-20mA, channel 1 outputs something like -3000 to 8500 4-20mA, and channel 2: -500 to 27600 4-20mA.  CH3-4 seem to work fine, so I'm using those.

Is it normal for these outputs to lose calibration over time? Or is this the sign of faulty electronics? Is this fixable?

Thanks

Hello,

you mean that -3000 to 8500 equals 4-20mA? Never heard of that in a proper running system.

Scott

have u try to deactivate unused channel?

or to ensure the module condition u can also replace it with another module