When a cylinder on a PLC controlled machine is moving out of sequence, what should a technician check next?

When troubleshooting a cylinder that is moving out of sequence in a PLC controlled machine, checking the PLC indicators for the correct sequence is crucial. The PLC (Programmable Logic Controller) is responsible for controlling the sequence of operations in the machine, including the timing and activation of various components such as cylinders.

By reviewing the PLC indicators, the technician can determine if there are faults in the programming or if the PLC is not receiving the correct input signals or sending the correct output signals to the actuators. If the PLC is functioning correctly and showing the expected sequence of operations, the technician can then eliminate potential programming errors as the cause of the issue, allowing them to focus on other areas such as mechanical problems or fluid supply issues.

This approach ensures a systematic troubleshooting process, beginning with the control system since it plays a central role in coordinating the machine's operations. This check can quickly reveal whether the root of the problem lies in the control logic or in the physical components of the system.