Re: New standards for small and medium sized astronomical observatories

[Jitendra Kodilkar <jkodilkar@gmail.com>]

Hi Piotr,

Useful discussion and info on how wide the EPICS technology being used among the Industry and Research organisations. I would like to update that the Giant Meterewave Radio Telescope (GMRT), India is being upgraded for wide-band observing capacity at low frequency (100 to 1500 MHz). We also planed to use the EPICS framework for the GMRT control and monitoring system. Around ~180 subsystems located at 30 antennas geographically distributed over 30 km^2 of area. Project active life for the Control and Monitoring system will be 2016 to 2030. For further information about the GMRT refer   http://www.gmrt.ncra.tifr.res.in. 

To evaluate the EPICS technology, we used two approaches, one is scenario based approach in which PoC (Proof of Concept) prototype-system is developed by considering the set of functional and non-functional requirements of the GMRT production version of M&C system. In another approach, the technologies were assessed on the basis of Usability, Sustainability and Maintainability criteria. Quantitative Assessment table is attached with email.

​The GMRT is operated by the National Centre For Radio Astrophysics(NCRA)​, Pune India. 

For more details about Experience with EPICS, refer paper by Martin R. Kraimer et al.  http://accelconf.web.cern.ch/accelconf/pac97/papers/pdf/5C003.PDF

With the Regards,

Jitendra

On 8 July 2014 20:13, Piotr Sybilski <sybilski@sybillatechnologies.com> wrote:

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

 

Attachment: QuantitativeAsessment.pdf
Description: Adobe PDF document