Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Tue, 22 Nov 2016 11:21:54 -0600

Hi Bo,

On 11/22/2016 02:24 AM, Bo Jakobsen wrote:
> It is still unclear to me if the problem is to get the ao record to
> process the value or if it is simply not possible to define the HIGH and
> LOW fields as CA links.

The HIGH and LOW fields of an ao record are just doubles, you can't make
them into links like you want to.

However, what types of records are your two $(P):SUBCRYO_SETP_MIN and
$(P):SUBCRYO_SETP_MAX limit records? If these are also ao records with a
soft-channel device support whose OUT fields are not already in use then
you could just point those OUT fields (which _are_ links) to point to
the $(P):SUBCRYO_SETP_S.LOW and $(P):SUBCRYO_SETP_S.HIGH fields
respectively, which would update them automatically whenever the user
modifies the source values.

If the OUT fields are already in use I would suggest using a SEQ record
to copy the values from those two into the LOW and HIGHT fields — a
calcout record can only copy one value so you'd have to have two of
them, whereas a single SEQ record can copy many values in a single
process operation.

- Andrew

> On 2016-11-21 15:12, Steiner, Mathias wrote:
>>
>> The brute force approach would be to use a calcout...
>>
>>  
>>
>> record(calcout, "$(P):SUBCRYO_SET_LOW") {
>>
>>   field(INPA, "$(P):SUBCRYO_SETP_MIN.VAL CP")
>>   field(CALC, “A”)
>>
>>   field(OUT , "$(P):SUBCRYO_SETP_S.LOW PP")
>> }
>>
>> ..and similar for .HIGH.
>>
>>  
>>
>> It’s the opposite of elegant but it’ll work.
>>
>>  
>>
>> cheers -mathias
>>
>>  
>>
>>  
>>
>> *From:*[email protected]
>> [mailto:[email protected]] *On Behalf Of *Bo Jakobsen
>> *Sent:* Monday, November 21, 2016 09:01
>> *To:* [email protected]
>> *Subject:* Linking a HIGH and LOW field to a PV
>>
>>  
>>
>> Hi
>>
>> I am trying to get "limits" to work on a "Soft Channel" record.
>> The challenge is that I have the limit values in another record, and
>> want to make a link between the two records.
>>
>> I would therefore like to something like this:
>>
>> record(ao, "$(P):SUBCRYO_SETP_S") {
>>   field(DESC, "Huginn Sub-cryostat system setpoint")
>>   field(DTYP, "Soft Channel")
>>   field(VAL, "300")
>>   field(PREC, "3")
>>   field(EGU, "K")
>>   field(PINI, "YES")
>>   field(HSV, "MINOR")
>>   field(LSV, "MINOR")
>>   field(LOW, "$(P):SUBCRYO_SETP_MIN.VAL CP")
>>   field(HIGH, "$(P):SUBCRYO_SETP_MAX CP")
>> }
>>
>>
>> which, however, does not work.
>> It this possible, and in that case how.
>>
>> Thanks in advance.
>>     Bo
>>
> 

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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System