The CPU error display (= = = =) means that a communications error has occurred between PLCs and the Programming Console.

Sometimes the CPU error display will appear even when the CPU Unit and the Programming Console are functioning normally. The possible reasons for this follow. Check each point to identify the problem.

When the Power to an Expansion Rack Has Been Interrupted

• If using an Expansion Rack, disconnect the Expansion Rack and turn ON the power to only the CPU Rack.
• Check to be sure the power supply to the Expansion Rack is operating properly.

When the Switch Setting Is Incorrect

• Check whether the pin 7 on the DIP switch on CQM1H Programmable Controllers are OFF.
• Check whether the pin 4 on the DIP switch on CS/CJ-series Programmable Controllers are OFF.

Other CPU Unit models do not have switch settings, so this does not need to be checked.

When There Is a Power Supply Failure

• Check the power supply on the primary side. If there is no problem, change the Power Supply Unit and check again.

Of course, it is possible that the Programming Console itself has failed, so check to see whether or not it will operate properly on another CPU Unit.

This applies to C200H-PRO27-E, CQM1-PRO01-E, and CQM1H-PRO01-E Programming Consoles.