Experimental Physics and
Industrial Control System

Ralph Lange <[email protected]> · Fri, 07 Jun 2013 10:36:33 +0200

On 07.06.2013 10:01, [email protected] wrote:
> From: [email protected] [mailto:tech-talk-
>> We would like to set a SCAN field on several lower level BO records, at
>> the same time, and the value of these SCAN fields should reflect the
>> value of the single higher level record SCAN field.
>>
>> For the control of these lower level SCAN fields another, higher level
>> record, would be used. If a user wishes to set individual lower level
>> record SCAN fields, she is allowed. OTOH, when changing the SCAN of the
>> higher level record, ALL lower lever BO records would get their SCAN
>> field set too.
>>
>> Is it possible to get this done without using a sequencer?
> I suggest an alternative architecture:
>
> 1. Have a single controlling record with controllable SCAN.
>
> 2. Set all your low level records to SCAN='Passive'
>
> 3. Use a chain of fanout records to force processing of the low level records
>
> 4. Use the FLNK of the controlling record to trigger the fanout.

Note, though, that this solution does not fulfill the requirement "OTOH,
when changing the SCAN of the higher level record, ALL lower lever BO
records would get their SCAN field set too." Once a BO has been set to a
different SCAN, it has to be changed back manually to "Passive" to get
scanned by the higher level SCAN period.

If you want the forced reset behaviour, you will have to replace the
fanouts by seq records that forward the high level SCAN to each of the
BO SCAN fields. Point some input link of the first seq to the higher
level SCAN field and make it CP to start the SCAN fanout chain whenever
the high level SCAN changes.

~Ralph

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System