Re: How to configure waveform record to read remote PV via PVAccess in EPICS

[Michael Davidsaver via Tech-talk <tech-talk at aps.anl.gov>]

On 3/30/26 8:29 AM, Varuna Crishan Meddage wrote:

Hi Michael,

Which address list you mean ? (there are multiple address lists)

"$EPICS_PVA_ADDR_LIST".  So what you show below is what I was asking about, and it looks consistent with your CLI session configuration.

Looking back, I forgot to ask which version of PVXS you are running.  If it is <= 1.4.0, then I can explain the issue you see as a bug which was fixed in 1.4.1.

* ioc: PVA link respect environment variables.  Previously defaults always used.

https ://epics-base.github.io/pvxs/releasenotes.html#aug-2025

Meanwhile I included following lines in my st.cmd file 

=================================================================================================================================

epicsEnvSet("EPICS_PVA_ADDR_LIST","239.128.1.6,8@eno1 10.200.21.28 10.200.21.29 10.200.12.73 10.200.16.47 10.200.16.40 10.200.16.58 10.200.16.59")

epicsEnvSet("EPICS_PVAS_INTF_ADDR_LIST","239.128.1.6")

epicsEnvSet("EPICS_PVAS_AUTO_BEACON_ADDR_LIST","NO")

epicsEnvSet("EPICS_PVA_AUTO_ADDR_LIST","NO")

EpicsEnvSet("EPICS_PVAS_BEACON_ADDR_LIST","239.128.1.7,10")

================================================================================================================================

After running the st.cmd file, I ran the pvxsr command and the output is

================================================================================================================================

epics> pvxsr

EPICS_PVAS_AUTO_BEACON_ADDR_LIST=NO

EPICS_PVAS_BEACON_ADDR_LIST=239.128.1.7:5076,10

EPICS_PVAS_BROADCAST_PORT=5076

EPICS_PVAS_IGNORE_ADDR_LIST=

EPICS_PVAS_INTF_ADDR_LIST=239.128.1.6:5075,-1 0.0.0.0

EPICS_PVAS_SERVER_PORT=42011

Source: __builtin prio=-1 

Source: __server prio=-1 

Source: acnet prio=0 

Source: qsrvSingle prio=0 

Source: qsrvGroup prio=1 

===============================================================================================================================

And still my subscribed PV is undefined

===================================================

epics> dbpr PIP2:CTRL_MPS:acq2106_347_follower

AMSG:               ASG :               DESC:               DISA: 0             

DISV: 1             NAME: PIP2:CTRL_MPS:acq2106_347_follower                    

NAMSG:              SEVR: INVALID       STAT: UDF           SVAL: 0             

TPRO: 0             VAL : 0             

==================================================

Where

record(longin, "$(acc):$(sys)_$(group):$(XRM-ID)_follower") {

    #field(INP, {pva:{pv:"$(acc):$(sys)_$(group):$(XRM-ID)_counter", "proc":"CP"}})

    field(INP, {pva:{pv:"acq2106_347:1:AI:WF:17:TH", "proc":"CP"}})

    #field(INP, "acq2106_347:1:AI:WF:17:TH CP")

}

Varuna

---

From: Michael Davidsaver <mdavidsaver at gmail.com>
Sent: Monday, March 30, 2026 12:03 AM
To: Varuna Crishan Meddage <vmeddage at fnal.gov>
Cc: kasemirk at ornl.gov <kasemirk at ornl.gov>; tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
Subject: Re: How to configure waveform record to read remote PV via PVAccess in EPICS

 

[EXTERNAL] – This message is from an external sender

On 3/26/26 9:09 AM, Varuna Crishan Meddage wrote:

Hi Michalel

Following is the output after printing out ENV variables.

It looks to me as if the address list is different between the two cases.  I suggest setting the full address list in the IOC environment.

==============================================================================

iocdev1$ env | grep EPICS_PVA
EPICS_PVA_ADDR_LIST=239.128.1.6,8@eno1 10.200.21.28 10.200.21.29 10.200.12.73 10.200.16.47 10.200.16.40 10.200.16.58 10.200.16.59
EPICS_PVAS_INTF_ADDR_LIST=239.128.1.6
EPICS_PVAS_AUTO_BEACON_ADDR_LIST=NO
EPICS_PVA_AUTO_ADDR_LIST=NO
EPICS_PVAS_BEACON_ADDR_LIST=239.128.1.7,10

==============================================================================

=============================== INSIDE EPICS SESSIION =============================

epics> pvxsr
EPICS_PVAS_AUTO_BEACON_ADDR_LIST=NO
EPICS_PVAS_BEACON_ADDR_LIST=239.128.1.7:5076,10
EPICS_PVAS_BROADCAST_PORT=5076
EPICS_PVAS_IGNORE_ADDR_LIST=
EPICS_PVAS_INTF_ADDR_LIST=239.128.1.6:5075,-1 0.0.0.0
EPICS_PVAS_SERVER_PORT=40515
Source: __builtin prio=-1
Source: __server prio=-1
Source: acnet prio=0
Source: qsrvSingle prio=0
Source: qsrvGroup prio=1

================================================================================

---

From: Michael Davidsaver <mdavidsaver at gmail.com>
Sent: Wednesday, March 25, 2026 7:47 PM
To: Varuna Crishan Meddage <vmeddage at fnal.gov>
Cc: kasemirk at ornl.gov <kasemirk at ornl.gov>; tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
Subject: Re: How to configure waveform record to read remote PV via PVAccess in EPICS

 

[EXTERNAL] – This message is from an external sender

On 3/25/26 1:54 PM, Varuna Crishan Meddage wrote:

Hi,

I created the following PV

===========================================

record(waveform, "PIP2:CTRL_MPS:acq2106_current")

{

  field(INP, {pva:{pv:"acq2106_347:1:AI:WF:17", "proc":"CPP"}})

  field(FTVL, "DOUBLE")

  field(NELM, "4096")

  field(SCAN, "1 second")

}

===========================================

But it complains that input PV is disconnected.

...

iocdev1$ pvxget acq2106_347:1:AI:WF:17

Is your IOC running with the same PVA configuration (environment variables) as your shell session?

fyi. At the IOC shell, run "pvxsr" to see the effective configuration (after auto address list expansion).

epics> pvxsr
EPICS_PVAS_AUTO_BEACON_ADDR_LIST=NO
EPICS_PVAS_BEACON_ADDR_LIST=192.168.1.255 10.127.127.255
EPICS_PVAS_BROADCAST_PORT=5076
EPICS_PVAS_IGNORE_ADDR_LIST=
EPICS_PVAS_INTF_ADDR_LIST=0.0.0.0
EPICS_PVAS_SERVER_PORT=5075

eg. If I run one instance of softIocPVX with

record(calc, "counter") {

    field(SCAN, "1 second")

    field(CALC, "VAL+1")

}

And a second with

record(longin, "follower") {
    field(INP, {pva:{pv:"counter", "proc":"CP"}})
}

I see that the "follower" record subscribes to the "counter"

epics> dbgf follower  
DBF_LONG:           59 = 0x3b  
epics> dbgf follower  
DBF_LONG:           60 = 0x3c