In our previous two issues, we discussed troubleshooting digital output modules. Troubleshooting analog modules is a bit more complicated, for two reasons: Analog modules aren't on/off, as digital ...

Does the module's output correspond correctly to its input? Determine that by forcing the PLC output to 10%, 25%, 50%, 75%, and 90% and measuring on the output terminals at the corresponding range.

New AC and DC discrete I/O modules include 8-point, 100-120 VAC input and output modules, 8- and 15-point, 3.3-24 VDC input and output modules and high-density, 32-point,12-24 VDC input modules. The I ...