What to Do When Analog Signals Jump, Drop, or Become Infinite During PLC Debugging?
Today, I will present an example of interference from a variable frequency drive (VFD) on a PLC’s analog signal and a solution using a signal isolation module to overcome such interference. 1. Example 1: Phenomenon Description In a Siemens PLC, the AO point outputs a 4-20mA current control signal to a Siemens VFD, but it … Read more