Beckhoff TwinCAT 3 (XAR/XAE) with EtherCAT fault ADS 6: Target port not found (0x6, ERR_TARGETPORTNOTFOUND)
Beckhoff: target port not found – the ADS server is not started, not reachable or not installed. The route to the target machine works (otherwise the error would be 7), but nothing is registered on the AMS port the client addressed, for example port 851 when PLC runtime 1 has no running PLC project.
Diagnose this with AI
Try Free PLC Fault Diagnostic Upload a keypad photo, the fault history or a parameter export from your Beckhoff TwinCAT 3 (XAR/XAE) with EtherCAT. InduQT compares the evidence and suggests the next useful checks.
When it happens
- When an HMI, SCADA or ADS client connects after a TwinCAT restart or download
- When the target is in CONFIG mode or the PLC project is not loaded
Likely causes and checks
1Wrong AMS port in the client
- Points to it
- Client uses 801 (TwinCAT 2) or another runtime port; the target is TwinCAT 3 with PLC runtime 1 on 851.
- Check
- Compare the client’s port with the ADS port of the PLC project (851 = TC3 PLC runtime 1, 852 = runtime 2…).
2No PLC project running on that port
- Points to it
- Target in CONFIG mode, no boot project, or the PLC was not started after activation.
- Check
- Check the TwinCAT state (RUN/CONFIG) and that the PLC project is loaded and running on the target.
3ADS server (e.g. an optional TwinCAT function) not installed on the target
- Points to it
- Error only on a non-PLC port (e.g. a TF server port); the PLC port works.
- Check
- Check the function is installed and licensed on the target and listed in the AMS port table.
Telling it apart
- ADS 7 means the target machine (AMS NetId / route) was not found; ADS 6 means the machine answered but nothing listens on that port.
- ADS 18 (port disabled) means the TwinCAT system service itself is not started on the target.
Relevant parameters
| Parameter | Name | Why it matters |
|---|---|---|
| AMS port | Target ADS port | TC3 PLC runtime 1 = 851, runtime 2 = 852; NC = 500; system service = 10000. |
Evidence to collect
- Client AMS NetId and port settings
- TwinCAT state of the target (RUN/CONFIG) and running PLC projects
- Logger output on the target around the connection attempt
- TwinCAT build of target and client
Work on fuel trains, burners, pressure vessels and electrical equipment must be done by qualified personnel following the manufacturer’s documentation and local codes. Never bypass a safety device or interlock.
Related
- Beckhoff TwinCAT 3 (XAR/XAE) with EtherCAT ADS 7: Target machine not found (0x7, ERR_TARGETMACHINENOTFOUND)
- Beckhoff TwinCAT 3 (XAR/XAE) with EtherCAT ADS 18: Port disabled (0x12, ERR_PORTDISABLED)
- Beckhoff TwinCAT 3 (XAR/XAE) with EtherCAT ADS 1861: Timeout, remote terminal not responding (0x745, ADSERR_CLIENT_SYNCTIMEOUT)
- All Beckhoff TwinCAT 3 (XAR/XAE) with EtherCAT fault codes