Ensure all motor cables and encoder cables are properly shielded, and the shielding is correctly grounded to the chassis or mounting plate. Electromagnetic interference (EMI) can result in seemingly random encoder errors or communication faults.
| Error Code (Hex) | Description | Troubleshooting Steps | | :--- | :--- | :--- | | | Motor Temperature Fault | 1. Motor is overheated. Allow it to cool. 2. If motor is cold, check the wiring of the temperature sensor (PTC/KTY) to the controller. 3. Verify parameter settings match the actual motor type. | | 0x8501 | Short Circuit (Output Stage) | 1. WARNING: Do not reset immediately. Disconnect motor cables. 2. Check for short circuits between U/V/W phases or to ground. 3. If wiring is good, the internal IGBTs may be blown. | | 0x8600 | Following Error (Lag Error) | The motor cannot reach the target position. 1. Mechanical Load: Check for jamming or increased friction. 2. PID Tuning: Increase Position Gain (Kp) or Velocity Gain. 3. Torque: The motor may be undersized for the application. | | 0x8700 | Limit Switch Triggered | 1. The axis hit a physical limit switch unexpectedly. 2. Move the axis away from the limit manually (jogging) before resetting. 3. Check the logic of the limit switch wiring (NC vs NO). | | 0x8xxx | Stall Detected | 1. The motor stopped moving while voltage was applied. 2. Check for mechanical blockages. 3. Increase motor current limit (if thermal safe). 4. Check the "Stall Detection Threshold" parameter. |
| Error Code | Name | Description | Immediate Action | | :--- | :--- | :--- | :--- | | | Under-voltage | DC link voltage < 18 V DC (nominal 24 V) | Check power supply capacity; measure at X1 terminals. | | 0x1200 | Over-voltage | DC link voltage > 32 V DC (regenerative braking issue) | Add external braking resistor; decelerate ramp longer. | | 0x1300 | Short Circuit | Phase-to-phase or phase-to-ground short in motor cable | Disconnect motor; test windings for resistance (<1 ohm indicates short). | | 0x1400 | Over-current | Instantaneous peak current > 5 A (software limit) | Reduce acceleration (object 0x6083h) or torque limit. |
Unlike simple drives, the CMMO-ST-C5-1-DIOP exposes internal registers via ISDU (Indexed Service Data Units). To predict failures before they become error codes: cmmo-st-c5-1-diop error codes
The Festo Configuration Tool (FCT) provides detailed history and exact error codes that simple blinking lights cannot show. Reset Errors: Try resetting the error using the input at the DIOP interface or through the software.
Run a manual jog of the axis (using either a PLC interface or FCT) to ensure smooth, unhindered mechanical travel end-to-end. Essential Maintenance and Best Practices
If the error returns within 10 seconds, it is a persistent fault, not a transient glitch. Ensure all motor cables and encoder cables are
: The sequence finishes with a two-digit specific code (e.g., 30 , 41 ). Sequence Example : If you see E →right arrow 04 →right arrow 10 repeating, the controller is throwing error 04-10 . Primary Diagnostic Groups and Error Codes Group 01: Power Supply and Voltage Faults
The internal memory has detected corrupted or missing motor configuration parameters. This often happens after a failed firmware update, an abrupt power loss during writing, or a hardware memory fault. Troubleshooting Steps:
Fix : Check for mechanical obstructions, guide rail binding, or a faulty holding brake that fails to release. If the mechanics move freely, connect the system to a PC using the Festo Configuration Tool via Ethernet and adjust the position controller stiffness (P-gain) or scale up the allowed tracking window. 4. Communication and Command Failures (Group 47 & 64) Motor is overheated
Here is a structured checklist to guide you through general troubleshooting steps.
The controller can be programmed to react to errors in several ways, defined by code letters from A to G. These parameters are set using the FCT.