Experimental Physics and
Industrial Control System

Open source and a large community of developer’s and uses may be an important factor for a scientific facility that needs to run for 25 years. I don’t know about the other two, but EPICS has a very active and supportive community with companies and scientific facilities that offer support to others in the community.

Look at the V4 web site for ideas about a road map. We are becoming clear on what is needed to support high level experiment control, data acquisition, data analysis, model based control, and standard services and prototypes of all of them are either deployed or in development.

It may be useful to attend an EPICS meeting if you are truly interested in the completeness of this table.

Bob Dalesio

 

 

Dear Madam/Sir

I am researching a subject of decoupling hardware and software components in small and medium sized astronomical observatories (up to 2.0 m): removing single point of failures (USB, RS232), introducing new standards and increasing the reliability and availability of observatories. I am software developer and architect for Project Solaris (4 autonomous observatories on 3 continents) and a start-up company working on control software. After a long research and many discussions within the community, we ended up with three solutions on the table:

-          DDS,

-          OPC UA,

-          EPICS.

 

My personal opinion can be summarized in this small table:

	DDS	OPC UA	EPICS
learning curve	steep	steep	steep
price for start-up	good	high	free
feature set	large	very large	very large
Support (community/commercial)	very good	very good	good
market share	high	very high	low
internet of things/future	well established	very well established	unknown
low memory/CPU devices support	good	very good	fair
Roadmap	clear	Clear	unknown

 

The table doesn’t show the clear winner but emphasizes that the DDS and OPC UA have brighter future, higher market share and better support. However I am not very familiar with EPICS, so I am probably missing a few points. Could you point me to the sources or give me more information on the comparison DDS vs OPC UA vs EPICS? During the last SPIE conference in Montreal I finished with votes (projects working and being happy with) 3 for OPC UA, 2 for DDS, 1 for EPICS and 1 for ZeroMQ.

 

I would be grateful for pros and cons of each technology that you can provide (our typical astronomical observatory consist of tens of devices, some of them redundant, real time communication is not required but quick event propagation and QoS is welcomed, some devices are simple sensors, some simple actuators, there are few devices that can produce bursts of data, for example CCD camera can produce 200 MB in one second, the data doesn’t have to be propagated through the system immediately, but shouldn’t choke the communication, some kind of prioritization is welcomed).

 

Best regards

Piotr Sybilski