Note: Since “cmmo-st-c5-1-diop” does not match a standard commercial HVAC, chiller, or VFD model from major brands (Carrier, Trane, Daikin, Mitsubishi, York), this post treats it as a generic or niche controller (possibly a chiller module, PLC, or OEM board). I have written the post to be useful for technicians encountering an unknown or legacy error code system.
Errors are shown as:
1: Often, numbers like this refer to a specific error or issue within a category. It could also indicate the severity or a sequence of errors. cmmo-st-c5-1-diop error codes
| Flashes | Meaning | |----------|-----------------------------| | 1 | Overvoltage / Undervoltage (24V DC power supply) | | 2 | Overcurrent / Motor short circuit | | 3 | Overtemperature (internal controller) | | 4 | Following error / position deviation | | 5 | Encoder error (if encoder feedback used) | | 6 | Software limit switch exceeded | | 7 | Parameter error (invalid config) | | 8 | IO-Link communication timeout |
to let you know exactly where a breakdown is happening in the logic or hardware. RS Components Common Error Categories & Diagnostics While specific hexadecimal codes (like Read Status word and Error code registers (addresses
Status word and Error code registers (addresses depend on IODD file).Don’t assume “CMMO-ST-C5-1-DIOP” is the primary controller. In some chillers, it’s only an expansion I/O board. The main error codes may be displayed on a different panel (e.g., a Carel or Danfoss controller). Trace the comms cable – you might find the real brain of the system.
Before diagnosing errors, one must understand the drive’s communication layers. The “DIOP” suffix indicates a variant with direct I/O and IO-Link communication. Errors typically propagate through three channels: Final Pro Tip Don’t assume “CMMO-ST-C5-1-DIOP” is the
Motion Errors: Includes "Drag error monitoring" (following error) and "Software end-position detection" if the motor cannot reach its target or hits a software limit.