When troubleshooting a PLC controlled machine, what is the first step?

The first step when troubleshooting a PLC (Programmable Logic Controller) controlled machine is to ensure safety by turning off the electric power. This is crucial because it prevents accidental activation of machinery while diagnosing issues. Safety is the top priority in any troubleshooting scenario, particularly with machines that may have moving parts or operate under pressure. Ensuring that the equipment is powered down protects the technician from potential hazards, including electrical shock or injury from mechanical movement.

While documenting the issue, checking program settings, and inspecting mechanical parts are all essential parts of the troubleshooting process, they should only be conducted after confirming that the machine is safe to approach. By first turning off the electric power, the technician can then proceed with a detailed investigation of the problem without the risk of unintended operation interfering with their work.