Experimental Physics and
Industrial Control System

I would like to announce the publication of a framework for helping to build EPICS IOCs.  The scope is somewhat in the spirit of Asyn, but the details and implementation are altogether unlike.  Some important differences:

1.       The interface to EPICS is completely synchronous.  Any decoupling of processing needs to be done explicitly and separately from the framework.

2.       The library is based on C99, not C++.  EPICS record type overloading is implemented via slightly scary use of macros (don’t look too closely if you’re of faint heart!)

3.       Device support is provided for the 11 basic EPICS record types (ai, ao, bi, bo, longin, longout, stringin, stringout, mbbi, mbbo, waveform) directly, there is no abstraction layer beyond this.

 

This framework has had a very long gestation.  Its first incarnation was as part of the implementation of Libera EBPM support, at least 8 years ago.  The second incarnation was inspired by work that James Rowland did on what he called “Generic” device support: his code was very concise and to the point, but only provided support for ai/ao records and waveforms of double.  Most recently this framework has been used to build device support for the Libera TMBF (Transverse Multi-Bunch Feedback processor) used at Diamond, and for our own X-ray photon beam position monitors.  This release is the result of extracting this framework as a standalone EPICS support module.

 

This framework depends on epicsdbbuilder, also published today, but is otherwise self contained.  I will shortly be publishing TMBF, which is a large implementation (560 records) using this framework.

 

epics_device can be found at https://github.com/Araneidae/epics_device

epicsdbbuilder can be found at https://github.com/Araneidae/epicsdbbuilder