The State of EPICS V4 (and V3) Development - January 2006

[Ned Arnold <nda@aps.anl.gov>]

With Marty Kraimer no longer available on a day to day basis, the APS 
team had to take a serious look at the EPICS development/support efforts 
in which we are involved.  Below is a summary of the conclusions reached 
 from a meeting with APS developers, APS management, Bob Dalesio, and 
Marty Kraimer.

Upon review of last year's efforts and accomplishments, we have realized 
that EPICS Version 4 is too large of development to successfully 
undertake with the part-time resources that can be leveraged from 
operating facilities.  In addition, the ambitious redesign of major 
portions of EPICS core (database, communications API, device support 
interface) would be a significant impediment for operating facilities to 
migrate to Version 4.

Therefore, under the current EPICS collaborative structure (and funding 
model), we have made a decision to focus on small incremental 
evolutionary steps (3.15, 3.16, etc) rather than revolutionary leaps. 
We will evaluate the desired features of V4 and develop a roadmap for 
incorporating some of these features into Version 3.  More significant 
changes/features will have to wait until new opportunities present 
themselves to fund substantial developments (there are a few ideas on 
the table, however).

Andrew Johnson has taken over responsibility of "keeper of the source". 
His primary emphases will be reliability, maintainability and 
establishing a well-defined forward migration path for existing 
applications as new features are added. Some features already identified 
for possible incorporation into 3.x include enhancement of the build 
system; unbundling BASE into Core, Channel Access, and IOC; variable 
length strings; etc. Because of our limited resources, we will be 
looking for significant assistance in developing these features (i.e. 
the timeline for delivery is directly proportional to available resources).

Some V4 research and development will continue, but not led or 
coordinated by Argonne. One effort will include investigation of 
hierarchical records, "devices", and emerging protocols. An initial 
implementation of some of these ideas will be in a Java IOC (Marty 
Kraimer is working on this development).  Another emerging development 
effort is the Control System Studio (a.k.a EPICS Office) and IOC 
redundancy driven by DESY.  Any successes in these areas will be 
considered for integration somewhere in the future. Contact Bob Dalesio 
or Matthias Clausen if you are interested in these activities.


  Ned Arnold (for The APS Team)