Experimental Physics and
Industrial Control System

"Troup, Euan \(CASS, Marsfield\) via Tech-talk" <tech-talk at aps.anl.gov> · Tue, 9 Feb 2021 05:00:02 +0000

Hi tech-talk,

I’m not sure if t his is the right forum, but I have a bit of a problem with a caproto-based IOC and alarms. The problem is if I have a PV that is updated with an alarm, a separate PV seems to inherit the alarm value when the second PV is updated.  If this is due to write-combining for efficiency, is there a way to turn it off? I have based the IOC on the io_interrupt.py example from the caproto package. The IOC code is below, and also some output from camonitor showing the alarms on the 2 PVs:

cheers,

Euan

import threading
import time

from caproto.server import pvproperty, PVGroup, ioc_arg_parser, run

def start_monitor(nv_callback):
    f = 1.0
    while True:
        time.sleep(1.0)
        nv_callback(f)
        f = (f + 1) % 20

class IOInt(PVGroup):
    stringv = pvproperty(value = '', record='stringin', max_length = 10)
    floatv = pvproperty(value = 0.0, record = 'ai', upper_alarm_limit = 18.0)

    @floatv.startup
    async def floatv(self, instance, async_lib):
        queue = async_lib.ThreadsafeQueue()
        thread = threading.Thread(target = start_monitor, daemon = True, kwargs = dict(nv_callback = queue.put))
        thread.start()

        while True:
            value = await queue.async_get()
            await self.stringv.write(str(value))
            await self.floatv.write(value)

if __name__ == '__main__':
    ioc_options, run_options = ioc_arg_parser(default_prefix = 'tio:', desc = 'test i/o interrupt')
    ioc = IOInt(**ioc_options)
    run(ioc.pvdb, **run_options)

camonitor -S tio:floatv tio:stringv
tio:floatv                     2021-02-09 15:48:12.750651 13  
tio:stringv 2021-02-09 15:48:12.750228 13.0  
tio:stringv 2021-02-09 15:48:13.751457 14.0  
tio:floatv                     2021-02-09 15:48:13.755341 14  
tio:stringv 2021-02-09 15:48:14.752766 15.0  
tio:floatv                     2021-02-09 15:48:14.753228 15  
tio:stringv 2021-02-09 15:48:15.753765 16.0  
tio:floatv                     2021-02-09 15:48:15.754194 16  
tio:stringv 2021-02-09 15:48:16.754858 17.0  
tio:floatv                     2021-02-09 15:48:16.755291 17  
tio:stringv 2021-02-09 15:48:17.755992 18.0  
tio:floatv                     2021-02-09 15:48:17.756392 18 HIHI MAJOR
tio:stringv 2021-02-09 15:48:17.755992 18.0 HIHI MAJOR
tio:stringv 2021-02-09 15:48:18.757027 19.0 HIHI MAJOR
tio:floatv                     2021-02-09 15:48:18.757424 19 HIHI MAJOR
tio:stringv 2021-02-09 15:48:19.758113 0.0 HIHI MAJOR
tio:floatv                     2021-02-09 15:48:19.758522 0 LOLO MAJOR
tio:stringv 2021-02-09 15:48:19.758113 0.0 LOLO MAJOR
tio:stringv 2021-02-09 15:48:20.759297 1.0 LOLO MAJOR
tio:floatv                     2021-02-09 15:48:20.759772 1  
tio:stringv 2021-02-09 15:48:20.759297 1.0  
tio:stringv 2021-02-09 15:48:21.760480 2.0  
tio:floatv                     2021-02-09 15:48:21.760907 2  

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System