Port status: NO_DEVICE / COM_ERR IFM — IO-Link communication lost (device not responding)
At a glance
- Severity
- WARNING
- Domain
- INSTRUMENTATION
- Reference standard
- IEC 61131-9 / IO-Link Specification V1.1
- Product / context
- Port communication error — AL1100/AL1350 IO-Link Master
What it means
The IO-Link master reports loss of communication with a device connected on a port. The device appears as unreachable, process data is not updated, and the master uses the configured substitute values. The port status LED on the master flashes red.
Probable causes
- Faulty M12 cable, crushed or with connector not properly tightened.
- Maximum IO-Link cable length exceeded (20m standard, unshielded).
- IO-Link device faulty or locked up (requires power cycle).
- IO-Link version incompatibility between master (V1.1) and device (V1.0) or IODD parameterization not matching the physical device.
Where to start
Check the status LED on the IO-Link device. Is the power LED on (device powered)?
Full guided diagnosis in the app
The diagnostic tree for this fault has 7 guided steps with measurements, checks and resolutions. You'll find it in ElectraIQ, one of the five IndexOS apps: free, works offline.
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The same fault on other brands
More IFM codes
- Signal quality warning — Noisy analog signal (electromagnetic interference)
- OOS — I/O Signal Out of Specification