Experimental Physics and
Industrial Control System

Mark Rivers via Core-talk <core-talk at aps.anl.gov> · Tue, 15 Jun 2021 17:40:30 +0000

> > Does this make sense in terms of IDL being built with an old version of base?
> Does this mean that IDL is using libca circa Base 3.13?
> Or does it have an independent implementation of the CA protocol?

Sorry, I should have said "Does this make sense in terms of ezcaIDL being built with an old version of base?", not IDL.  IDL does not have any built-in Channel Access support.  It is provided through 3 libraries in EPICS extensions, plus EPICS base.

- ezca https://github.com/epics-extensions/ezca

- EzcaScan https://github.com/epics-extensions/EzcaScan

- ezcaIDL https://github.com/epics-extensions/ezcaIDL

These get linked into a shareable library (Linux) or DLL (Windows) that is dynamically loaded at run-time by IDL.

I initially wrote ezcaIDL in 1995 and ran it on UNIX and VMS.  I added Windows support in 1998, and support for 3.14 in 2003.  So there were definitely versions of the DLL that used 3.13 and maybe it was one of those very old versions that was still in use at NSLS-II.

Mark

________________________________
From: Michael Davidsaver <mdavidsaver at gmail.com>
Sent: Tuesday, June 15, 2021 12:28 PM
To: Mark Rivers
Cc: Zimoch Dirk (PSI); core-talk at aps.anl.gov
Subject: Re: CA incompatibilities?

On 6/15/21 10:25 AM, Mark Rivers wrote:
> The report I received (indirectly) from the NSLS-II controls group was:
>
>
> "The new EPICS version on the IOC server will not process
> CA_PROTO_SEARCH request without first seeing a CA_PROTO_VERSION
> request (CA protocol actually requires this). The IDL packets do not
> contain the required CA_PROTO_VERSION (16 bytes)."
>
> Does this make sense in terms of IDL being built with an old version of base?

Yes.

Does this mean that IDL is using libca circa Base 3.13?
Or does it have an independent implementation of the CA protocol?

(obviously I've never looked at IDL before)

> Mark
>
>
> ________________________________
> From: Core-talk <core-talk-bounces at aps.anl.gov> on behalf of Michael Davidsaver via Core-talk <core-talk at aps.anl.gov>
> Sent: Tuesday, June 15, 2021 11:20 AM
> To: Zimoch Dirk (PSI)
> Cc: core-talk at aps.anl.gov
> Subject: Re: CA incompatibilities?
>
> On 6/15/21 8:39 AM, Zimoch Dirk (PSI) via Core-talk wrote:
>> One of my customers complained that his EPICS 3.13.2 client cannot connect any longer since the IOC has been upgraded
>> from 3.14.12 to 7.0.5.
>
> I checked and 'caget' from the current 3.14 works with 'softIoc' from current 7.0.
>
>> (Don't tell me that  he should upgrade, please.)
>
> I won't tell you that he _must_ upgrade, but I will certainly say that he _should_.
>
>> Searching the release notes, I found that support for clients < V4 (< EPICS R3.12.0-beta1) are not supported any longer
>> since 3.16.1. But the client is question reports V4.8.
>> Was there another CA compatibility drop since 3.16.1?
>
> No.  Though, my change which dropped support for < 3.12 actually seems
> to have dropped support for < 3.13.  I have no way to test anything
> before 3.14, so I'm not certain of this.
>
> https://github.com/epics-base/epics-base/pull/141#discussion_r602439829
>
> While I don't anticipate any further deprecation of older CA protocol
> versions, it should be noted that interoperability with older versions
> is getting little to no testing.  It is inevitable that regressions
> will creep in unless those with a continuing interest regularly test
> the latest developments with these oldest versions.
>

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System