Re: PV value logging

[Bruce Hill <bhill@slac.stanford.edu>]

Hi Vikram,
If you're not familiar with camonitor, you might want to
try it for a quick and simple logger.
It's built when you build base and installed in the same
directory as caget, i.e. $(EPICS_BASE)/bin/<host_arch>

It doesn't satisfy your criteria for always running when the ioc runs,
or long term archival, but just running "camonitor <pv_name>"
will print a msg to stdout each time the PV updates.

Regards,
- Bruce

On 05/17/2013 02:51 PM, Ralph Lange wrote:

Hi Vikram,

OK, then you're basically looking for two different things.

A) CaPutLog
Facility that you hook into the AccessSecurity layer. [1]
Then you can configure records for CA Put logging, i.e. any Channel Access put operation will be logged with timestamp, user, host, channel, old value, new value. By default logging is done through a TCP connection, so you can set up one server, and all your IOCs can log into that machine.

B) Archiving
Long term logging of values with timestamps is usually called archiving in the EPICS context.
There are a whole bunch of solutions, you can pick one.
Channelarchiver [2]: the traditional EPICS archiver, written in C, fast, stable, binary file format, clients retrieve data through XMLRPC.
CSS-Archiver [3]: written in Java, easier to configure, more analysis tools, good integration into CSS, archives into RDB (Oracle, MySQL, PostgreSQL).
Archive Appliance [4]: Java web service, easiest to configure, scales well, lightning fast (especially for retrieval), binary file format (pluggable).

[There are more solutions. The keyword lists for the three choices I suggested are far from complete and just to give a first idea.]

Well ... now it's your turn to check things out and make up your mind.

Cheers,
~Ralph

ps. If a Debian-based Linux distribution is ok for you: epics-base, caputlog and channelarchiver are available as Debian binary packages and will get you started very fast and easy. [5]

[1] http://www-csr.bessy.de/control/SoftDist/caPutLog/
[2] http://epicschanarch.sourceforge.net/
[3] http://sourceforge.net/apps/trac/cs-studio/wiki/RDBArchive
[4] http://epicsarchiverap.sourceforge.net/
[5] http://epics.nsls2.bnl.gov/debian/



On Fri May 17 2013 14:17:05 GMT+0200 (CEST), Vikram Bhagat <vbhagat@rocketmail.com> wrote:

Hi Ralph,

--What do you want to log?    I want to log value with Timestamp. My record scanning rate is 1 Second and i want to log at same rate. I also have some PV having I/O Intr. in that case at the time of value change.   

For outputs:  Value change by operator.  and want to log the changed value with time.

-- How long do you want to log? (just during a test setup? over long periods? forever?)   It should be log value it IOC run.  we can say forever.

-- What do you want to do with the information? (use it for debugging? create plots of values over time?)   - it can be used for analysis and create plots.

-- Where do you want to log? (local on IOC console? remote on a different, maybe central, server?)   locally may be in some file etc.

Thank you very much.

---

From: Ralph Lange <Ralph.Lange@gmx.de>
To: Vikram Bhagat <vbhagat@rocketmail.com>
Cc: EPICS Tech Talk <tech-talk@aps.anl.gov>
Sent: Friday, May 17, 2013 1:42 PM
Subject: Re: PV value logging

On Fri May 17 2013 11:22:27 GMT+0200 (CEST), Vikram Bhagat <vbhagat@rocketmail.com> wrote:

Hi,

      How i can enable logging of EPICS PV value?  For example logging input PV (record type ai or bi)  and even set PV (record type ao or bo) also.   

I have used Asyn driver for my application.

Thanks

The answer depends on:

- What do you want to log? (value? timestamp? alarm status? For outputs: also who changed it? from where? old and new value?)
- How long do you want to log? (just during a test setup? over long periods? forever?)
- What do you want to do with the information? (use it for debugging? create plots of values over time?)
- Where do you want to log? (local on IOC console? remote on a different, maybe central, server?)

If you supply a more complete specification of your request, people will be able to point you to the best solution.

Thanks,
~Ralph

-- 
Bruce Hill
Member Technical Staff
SLAC National Accelerator Lab
2575 Sand Hill Road M/S 10
Menlo Park, CA  94025