ADS driver 3.2.0 and autoparamDriver 2.1.0

[Jure Varlec via Tech-talk <tech-talk at aps.anl.gov>]

Dear all,

I'm pleased to announce that ADS driver 3.2.0 and autoparamDriver 2.1.0 have just been released. I'd like to thank Dennis Hilhorst (High Voltage Engineering) for his work on logging, and Markus Meyer (HZDR) for adding output readback support. And because we didn't post the announcement for the previous releases, I'd also like to thank Freddie Akeroyd and Jack Harper (STFC) for adding support for WIndows and TwinCAT.

The ADS driver is an EPICS module for integrating Beckhoff PLCs. Communication happens over the ADS protocol, decoupling the IOC from PLC's real-time loop, in contrast to the EtherCAT protocol. No special network hardware is needed on the IOC side. This module reads variables from the PLC in batches, offering good performance and low overhead when reading many variables.

autoparamDriver is a C++ class building on top of asynPortDriver. It is most useful for creating asyn drivers that do not know ahead of time which parameters they will have, and rely on the EPICS database to define this. The ADS driver is a good example: the database, not the driver, defines which variables will be read from the PLC.

Both modules and their documentation may be found at https://epics.cosylab.com

Notable changes in the ADS driver:

• Added support for asyn:READBACK. This allows updating output records with the actual value of the ADS variable.
• Only update waveforms when data has changed. This implements the same behavior as for scalar records.
• Major changes to error logging. All missing variables are logged, not just the first one. However, to prevent flooding the logs when name resolution fails completely, errors are not logged on every poll period. In addition, the IOC console is less verbose when no errors are encountered.
• The bundled Bechkoff ADS library was updated.
• PLC connection status is now synced to the connection status of the asyn port. The port is always in autoconnect mode, but the CNTC field of asynRecord does show the actual connection status.
• The waiting period between connection attempts is now configurable.

Notable changes in autoparamDriver:

• Added support for getParam() function to read parameter values.
• Improved port shutdown to use ASYN_DESTRUCTIBLE when available, with fallback to the existing approach for older asyn versions.
• The shutdowPortDriver() function is made available also on older asyn versions, keeping source compatibility.
• The Octet string wrapper is made safer to use by requiring the passed buffers to include null-termination of the string. This was already the case before, but was implicit, and is now explicit.

Best regards,
Jure Varlec