Questions about Rockwell
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Our company has a Rockwell control system that consists of four separate control units, all controlled by the same PLC. The processes for these four control units are identical; when three of them are started simultaneously, they all operate normally. However, if all four are started at once, it causes the system to trigger an alarm and shut down. Alarms occur randomly, and each alarm is different; they are mostly pump failure alarms. The entire control system consists of two ControlNet networks, 28 frequency converters, and 9 field cabinets. The 28 inverter rooms are located separately in the power distribution room. The wires that connect the 9 field cabinets to the power distribution room consist only of 220V and 24V power supplies as well as communication wires, all of which are arranged in a cable tray. The system is also connected to a separate ground wire. What could be the possible reasons for this? All communication cables are routed separately from high-voltage cables, and shielding is used at all points where they intersect!
First, confirm whether the PLC shuts down or encounters an error after a system alarm is triggered. If the PLC is operating normally, it is either a problem with the application software or with the wiring hardware; in the case of a pump alarm, the relevant information should be checked. For debugging instructions, flag bits for each stage can be added to determine the program’s execution. For reference only.
The wires have been replaced, and the inverter is also controlled via ControlNet – could this have an impact on the control system?
What is ControlNet? Who can give an explanation?