Hello Ignacio,
It depends on exactly what you want to achieve. If you want to create a Normative Types PV from your regular EPICS database, you might want to use the PV groups [1].
You also can do a lot by using PVA links [2] in your database records.
In the example below you would read from PVA to a longin record:
record(longin, "$(P)$(R)DBRInput") {
field(DESC, "Copy of PVAInput")
field(INP, {pva:{pv:"$(P)$(R)PVAInput",proc:true}})
}
You can also do the other way around and write to a Normative Types PV:
record(longout, "$(P)$(R)DBROut") {
field(DESC, "write using PVA")
field(OUT, {pva:{pv:"$(P)$(R)PVAOut"}})
}
PVA links are available in the pva2pva library that is part of EPICS Base already, and soon will be also in PVXS (QSRV2).
But if you need at a more "complex" integration, I would definitively go for PVXS inside you IOC [3]. You can use the aSub record to read from your regular DBR PVs (records) and from there you can use the SharedPV class from PVXS to do whatever you want. Bruno
Martins has a very nice example [4]. If your "old" IOC runs EPICS Base 7+ and QSRV is enabled, it is already producing Normative Types PVs that could be accessed by a PVXS client context via read (get) and subscription (monitor) operations inside the same
IOC.
[1] - https://epics-base.github.io/pva2pva/qsrv_page.html#qsrv_group_def
[2] - https://epics-base.github.io/pva2pva/qsrv_page.html#qsrv_link
[3] - https://indico.fnal.gov/event/58280/contributions/264559/
[4] - https://github.com/brunoseivam/tabulator/blob/main/stackerApp/src/stackerSup.cpp
Kind regards,
João Paulo Martins
European Spallation Source ERIC