If an error occurs immediately upon power-up, it is likely a Hardware/Wiring issue. If it occurs during movement, it is likely a Parameter/Mechanical issue (e.g., following error). Software Limits:
Festo CMMO-ST-C5-1-DIOP is a compact stepper motor controller designed for point-to-point and interpolating motion. When a fault occurs, the device displays a hexadecimal error code on its 7-segment display
Overvoltage in the logic power supply. The 24V DC input exceeds acceptable tolerances (+15%).
Errors on the CMMO-ST series are generally categorized by their prefix and impact on operation: Code Prefix Action Level Immediate stop; requires a reset (CCON.RESET). Informational; does not necessarily stop movement. Parameterization Setup issue; check FCT (Festo Configuration Tool) settings. 2. Frequent Error Codes & Troubleshooting
Exceeding load limits or operating outside the 0–50°C ambient temperature range. Troubleshooting Steps cmmo-st-c5-1-diop error codes
The difference between the setpoint and actual position is too large.
Look for "Warnings" that occur before a "Fault". For example, you may see Warning: Overtemperature followed 5 seconds later by Fault: Overtemperature . This tells you that cooling is insufficient, not that the sensor is broken.
Validate timeout settings ( CCON.RESET ), inspect RJ45 connectors, and check shield grounds. (Under/Overvoltage)
Connect via Ethernet to view the full error buffer with detailed timestamps and descriptions. Web Browser: If an error occurs immediately upon power-up, it
Re-download a known, working parameter set or upload the factory default settings for your specific motor (e.g., EMMS-ST) and recalibrate.
The is a compact, closed-loop stepper motor controller designed to drive stepper motors like the Festo EMMS-ST series using digital I/O (PNP switching) logic. When system faults occur, the controller indicates issues through diagnostic LEDs, binary output patterns, and hexadecimal fault codes within the Festo Configuration Tool (FCT) software.
The CMMO-ST-C5-1-DIOP employs a three-tier classification system for diagnostic messages. These classifications can be parameterized using the Festo Configuration Tool (FCT).
Adjust your position window and acceptable following error tolerances in the FCT parameterization menu. When a fault occurs, the device displays a
The variance between the target position and actual position exceeds the software threshold. Increase the following error limit in the FCT parameter cloud, check the encoder cable connection on the [X2] port, or reduce physical machine load.
: CMMO-ST-C5-1-DIOP identifies a stepper motor controller ( ST ) with a 5A nominal current ( C5 ), 24V DC input ( 1 ), and a PNP digital I/O interface ( DIOP ).
4 flashes ( Excess position error )
The CMMO-ST-C5-1-DIOP is a robust controller, but effective troubleshooting depends on interpreting the diagnostic LEDs and using the FCT software to identify specific hexadecimal errors. By addressing power, motor connections, and configuration, most errors can be resolved quickly. To help you specifically, are you seeing: A specific error code in the FCT software (e.g., )? The issue happening during power-up or during movement? Knowing this will allow me to narrow down the exact cause. Share public link
or interpreted from the 7-segment display on the device front. Common Error Categories