What does error code E41 on a Series Three PLC mean?
November 27th, 2018
Error code E41 is displayed when the Series Three CPU detects a change in I/O module configuration or if an error occurs when transferring data between I/O modules and the CPU. It is normal for this error code to appear whenever I/O modules are added or removed from the system, or when I/O modules are relocated from one slot to another in the base unit. In most circumstances, an E41 error can be cleared by placing the key switch on the front of the Series Three CPU in the RUN 1 position and pressing the SET key. If this procedure fails to clear the error, a fault may be present in the hardware of the CPU, one or more I/O modules, or the base unit. Our technical support staff will be glad to assist you in pinpointing the source of this and other Series Three PLC errors. We can be reached by phone at or through email to. For information on other error codes, please refer to "Series Three Error Code Definitions" available on the Series Three documentation page.