FAQ - frequently asked questions and answers
In this section frequently asked questions are answered, in order to facilitate your work with the TwinCAT Usermode Runtime. If you have any further questions, please contact our support team at support@beckhoff.com.
- How do I start the TwinCAT Usermode Runtime?
- What does the error message mean: too little memory when using the PLC?
- How can I access the Usermode Runtime remotely?
- How is a collision of the AmsNetId prevented?
How do I start the TwinCAT Usermode Runtime?
You can start the Usermode Runtime via the "start.bat" in your respective ProgramData folder. It can then be selected as a target system via the Automation Interface and can be used in the same way as other systems in terms of Activate Configuration and changing the state.
What does the error message mean: too little memory when using the PLC?
If you get this error when logging in (or through the autostart):
your application requires more memory than the Usermode Runtime provides by default.
A file 3.1/TcRegistry.xml is available in the ProgramData directory of the Usermode Runtime, which you can use to change this configuration. Insert a value "HeapMemSizeMB", which specifies a value in megabytes. Here it is 512 MB:
How can I access the Usermode Runtime remotely?
The Usermode Runtime has its own router component and its own AmsNetId. The Usermode Runtime logs on to the system router component so that it can be reached locally via its own AmsNetId.
If the Usermode Runtime is to be accessible from another system, the file 3.1\StaticRoutes.xml can be extended in its ProgramData directory, as described in the documentation TwinCAT 3 ADS-over-MQTT.
How is a collision of the AmsNetId prevented?
A Usermode Runtime requires a unique AmsNetId on the system. This is saved in the configuration in your ProgramData directory 3.1\TcRegistry.xml.
If a Usermode Runtime has already occupied this AmsNetId at startup, the 2nd byte is incremented: 199.4.42.250.1.1 thus becomes 199.5.42.250.1.1.