Beckhoff TwinCAT 3 ADS Error 18 (0x12) after boot, why?
I'm getting an ADS Error 18 (0x12) on my TwinCAT 3 runtime after the PC boots up. The HMI on this machine can't connect to anything. What should I check first?
ADS Error 18 (0x12) indicates that a port is disabled because the TwinCAT system service is not running. This typically occurs right after a PC boot or if the TwinCAT runtime has stopped or failed to start. The error means the local ADS router is not active, preventing any ADS port from being reached.
Likely causes and checks
1TwinCAT system service stopped or not yet started
- Points to it
- The ADS router on the machine is not running, which means no ADS port can be reached. This is common right after booting the PC, before the TwinCAT system service has had a chance to start.
- Check
- Check the TwinCAT system service state on the machine that is returning the error. You can also look for the TwinCAT SysTray icon to see if it's running.
2TwinCAT runtime failed to start
- Points to it
- The TwinCAT runtime might have encountered an issue preventing it from starting correctly, such as real-time not being available on the PC. This would also lead to the ADS system service not running.
- Check
- Read the logger and Windows event log for any TwinCAT start errors on that machine.
Next check: First, verify the status of the TwinCAT system service on the affected machine and check the TwinCAT SysTray icon. If the service is not running, attempt to start it.
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