Experimental Physics and Industrial Control System

Here is a simple example. It monitors a PV ‘catest’ and synchronise its value to `MTEST:PROXY’

######
from pcaspy import Driver, SimpleServer
from CaChannel import ca, CaChannel

prefix = 'MTEST:'
pvdb = {
    'PROXY': {
    }
}

class myDriver(Driver):
    def __init__(self):
        Driver.__init__(self)
        self.chan = CaChannel('catest')
        self.chan.searchw()
        self.chan.add_masked_array_event(None, None, None, self.value_callback)

    def value_callback(self, epics_args, user_args):
        self.setParam('PROXY', epics_args['pv_value'])
        self.updatePVs()

if __name__ == '__main__':
    server = SimpleServer()
    server.createPV(prefix, pvdb)
    driver = myDriver()

    while True:
        # process CA transactions
        server.process(0.1)
#######

> On 30 Mar 2017, at 17:45, lzf neu <[email protected]> wrote:
> 
> Thank you! 
> 
> I have a new question to consult you:
> 
> I want to get the return value of caget('some PV name') by writing Pcaspy script. I have no idear what command to use in the script. 
> Any suggestions will be appreciated ! 
> 发件人: Kasemir, Kay <[email protected]>
> 发送时间: 2017年3月29日 12:46:30
> 收件人: lzf neu
> 抄送: [email protected]
> 主题: Re: Question about PV name by using pcaspy
>  
> 
>> On Mar 29, 2017, at 3:37 AM, lzf neu <[email protected]> wrote:
>> 
>> Hi,
>> 
>> I want to fulfill a goal that when running camonitor command, PV name TEST:PING in the terminal window print "Disconnect!" or "OK!" alternatively.
>> 
>> However, I failed, "self.setParam('PING',a)"  seems only run once in the code and in terminal window only print one result.
>> 
>> I have posted the code in the following lines.
>> 
>> Could you give me some suggestions and any help will be appreciated.
> 
> 
> You’re missing a call to
>    self.updatePVs()
> 
> -Kay
> 
> 
>> 
>> Zhefu
>> 
>> #===============================
>> #!/usr/bin/env python
>> import os
>> import threading
>> import time
>> 
>> from pcaspy import Driver, SimpleServer
>> prefix = 'TEST:'
>> pvdb = {
>>     'PING' : {
>>          'type':'enum',
>>          'enums':['Disconnect!','OK!']
>>     },
>> }
>> 
>> class myDriver(Driver):
>>     def __init__(self):
>>         super(myDriver, self).__init__()
>>         tid=threading.Thread(target=self.determine)
>>         tid.setDaemon(True)
>>         tid.start()
>> 
>>     def determine(self):
>>         a=os.system("ping -c 1 -w 1 127.0.0.1")
>>         if (a==0):
>>           while True:
>>              self.setParam('PING',a)
>>              a=not a
>>              time.sleep(5)
>> 
>> if __name__ == '__main__':
>>     server = SimpleServer()
>>     server.createPV(prefix, pvdb)
>>     driver = myDriver()
>> 
>>     # process CA transactions
>>     while True:
>>         server.process(0.1)
> 

References:

Question about PV name by using pcaspy lzf neu

Re: Question about PV name by using pcaspy Kasemir, Kay

答复: Question about PV name by using pcaspy lzf neu

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