Experimental Physics and
Industrial Control System

Wang Xiaoqiang <[email protected]> · Mon, 29 Aug 2016 15:35:41 +0200

Hi,

Yes. The scan value can be arbitrary, and each PV has its own scan thread.

If you have many PVs to poll, you can instead poll them sequentially in

a thread.

	def __init__(self):
            Driver.__init__(self)
            tid = threading.Thread(target=self.poll)
            tid.setDaemon(true)
            tid.start()

        def poll(self):
            # get values from the device
            <<get value1>
            <<get value2>
            <<get value3>
            # set to the pv database
            self.setParam("value1", value1)
            self.setParam("value2", value2)
            self.setParam("value3", value3)
            # post the monitor event
            self.updatePVs()

Then you don't need to set the scan field, and omit the read method.

Such an example is here

https://github.com/paulscherrerinstitute/pcaspy/blob/master/example/simscope.py.

It runs a simulation task and publish the results periodically.

On 08/29/2016 02:22 PM, Silver wrote:

hi, xiaoqiang:

Thanks a lot for your letter. In fact, pcaspy is very convinent and
helpful for me, thanks for your work.

I have another question, can scan field be set to a arbitrary value such
as 0.001? If it can work, corresponding, the server.process(0.01) will
be set instead of server.process(0.1)?

------------------------------------------------------------------------
Best wishes
Geyang 2016-08-29

    *发件人：* Wang Xiaoqiang <mailto:[email protected]>
    *发送时间：* 2016-08-29 15:34
    *收件人：* geyang <mailto:[email protected]>; tech-talk
    <mailto:[email protected]>
    *主题：* Re: question about pcaspy
    Hi,
    According to
    http://www.aps.anl.gov/epics/base/R3-14/12-docs/CAref.html#Configurin2,
    you can set EPICS_CAS_SERVER_PORT
    # on the server side
    $ export EPICS_CAS_SERVER_PORT=5078
    $ python dummy.py
    # on the client side
    $ export EPICS_CA_SERVER_PORT=5078
    $ caget MTEST:RAND
    MTEST:RAND 0.000 (SEVR:INVALID STAT:UDF)
    But if the same driver is instantiated for many devices, you can create
    the database with different prefixes.
    if __name__ == '__main__':
          ...
          prefix = sys.argv[1]
          server.createPV(prefix, pvdb)
          ...
    Then to run the server for each device
    $ python dummy MTEST1:
    $ python dummy MTEST2:
    Best
    Xiaoqiang
    On 08/28/2016 02:45 AM, geyang wrote:
     > hi,
     >
     >    I would like to ask if  SimpleServer's port can be changed to
    others
     > in code, such as 5066/5068? For example, I have a device driver
    written
     > by pcaspy, I want to implement the same driver for many same type
     > devices on one machine, then I need to set them different server
    ports.
     >    thanks a lot for your help.
     >
     >
     > Best wishes
     > Geyang 2016/8/28
     >
     >
     >

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System