Re: [EXTERNAL] PVXS and Phoebus

["Kasemir, Kay via Tech-talk" <tech-talk at aps.anl.gov>]

"Boolean" PVs like those created by bi, bo records don't serve "boolean" data as one might expect.

They instead serve enumerated data like this:

epics:nt/NTEnum:1.0

    enum_t value (0) OK

        int index 0

        string[] choices [OK, Error]

Phoebus as a generic operator interface/client decodes the types provided by the IOC.

It's not prepared to handle any arbitrary data that custom clients might generate.

Having said that, I think it's a good idea to be more lenient and also support "boolean" data, even if no IOC at this time will generate it, so  I've added that to the list: https://github.com/ControlSystemStudio/phoebus/issues/2410

-Kay

---

From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Florian Feldbauer via Tech-talk <tech-talk at aps.anl.gov>
Sent: Wednesday, October 5, 2022 10:40 AM
To: tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
Subject: [EXTERNAL] PVXS and Phoebus

 

Hey all,

I have written a small program using the PVXS library. Trying to access
the PVs with Phoebus release 4.7.0 I encountered an issues:

I'm using a boolean button widget in Phoebus to access a NTScalar with
boolean type and get the message "Cannot decode ..."

In the shell I get the message:

2022-10-05 16:24:10 WARNING [org.phoebus.pv] Cannot decode
'PND:LMD:RUNCTRL:SHUTDOWN' [CID 2, SID 117768961 CONNECTED] =
epics:nt/NTScalar:1.0
     boolean value false
     alarm_t alarm [NO_ALARM]
         int severity 0
         int status 0
         string message
     time_t timeStamp [2022-10-05 16:23:26.000318114]
         long secondsPastEpoch 1664979806
         int nanoseconds 318114
         int userTag 0
java.lang.Exception: Expected struct with scalar 'value', got
epics:nt/NTScalar:1.0
     boolean value false
     alarm_t alarm [NO_ALARM]
         int severity 0
         int status 0
         string message
     time_t timeStamp [2022-10-05 16:23:26.000318114]
         long secondsPastEpoch 1664979806
         int nanoseconds 318114
         int userTag 0
     at
org.phoebus.pv.pva.PVAStructureHelper.decodeScalar(PVAStructureHelper.java:148)
     at
org.phoebus.pv.pva.PVAStructureHelper.getVType(PVAStructureHelper.java:99)
     at org.phoebus.pv.pva.PVA_PV.handleMonitor(PVA_PV.java:88)
     at
org.epics.pva.client.MonitorRequest.decodeValueUpdate(MonitorRequest.java:236)
     at
org.epics.pva.client.MonitorRequest.handleResponse(MonitorRequest.java:198)
     at
org.epics.pva.client.MonitorHandler.handleCommand(MonitorHandler.java:40)
     at
org.epics.pva.client.MonitorHandler.handleCommand(MonitorHandler.java:21)
     at
org.epics.pva.common.CommandHandlers.handleCommand(CommandHandlers.java:66)
     at
org.epics.pva.client.ClientTCPHandler.handleApplicationMessage(ClientTCPHandler.java:331)
     at org.epics.pva.common.TCPHandler.handleMessage(TCPHandler.java:394)
     at org.epics.pva.common.TCPHandler.receiver(TCPHandler.java:294)
     at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
     at
java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
     at
java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
     at java.base/java.lang.Thread.run(Thread.java:833)

Is the boolean type not implemented in Phoebus? In that case I would
switch to an int value.


Cheers,
Florian


--
Ruhr-Universität Bochum
AG der Experimentalphysik I
Dr. Florian Feldbauer
NB 2/131 / Fach 125
Universitätsstr. 150
D-44801 Bochum

Office: NB 2/134
Phone:  (+49)234 / 32-23563
Fax:    (+49)234 / 32-14170
https://paluma.ruhr-uni-bochum.de