Experimental Physics and
Industrial Control System

Maren Purves <[email protected]> · Mon, 28 Feb 2005 11:53:48 -1000

Thanks to Marty and Paul.
Maren
(won't be able to test this for another week - 10 days)
Paul Sichta wrote:

The Calcout record (and some other records) have IVOA and IVOV fields
that force a user-specified output value if the record's status (or INP
links if MS is specified) goes to INVALID. So, you could follow Marty's
concept but get away with only one new record.
-ps

----- Original Message ----- From: "Marty Kraimer" <[email protected]>
To: "Maren Purves" <[email protected]>
Cc: <[email protected]>
Sent: Monday, February 28, 2005 8:13 AM
Subject: Re: calc record question

Maren Purves wrote:
Hi all,
I need/partly have the following application:
An IOC provides a (floating point, if that matters) number that
depends on something in this IOC to another IOC where it needs
to be added into a calc record. We do this in other places, and
in itself it isn't a problem. The question I have is:
What happens if the first IOC is switched off?
(The number it contributes should be switched to 0.0 before it
is turned off. This IOC may be switched off for months at a
time.)
Will the calc record treat the non-existing input as a 0?
Will it also do so when it is rebooted?
Thanks,
Maren
(trying to avoid putting in a switch)

The calc record will continue to use the value it last obtained or 0.0
if it never got a value from the other ioc. If you specify MS on the
link the calc record will go into alarm if the other IOC is down.
Here is a way to do what you require. Create the following two
additional records
record(ai,"<actualLink>") {
   field(INP,"<pvInOtherIOC> CP MS")
}
record(calc,"<checkStatus>") {
   field(INPA,"<actualLink> ")
   field(INPB,"<actualLink>.SEVR")
    #SEVR=3 means INVALID_ALARM
   field(CALC,"(B=3)?0.0:A")  }

Than have your original calc record link to <checkStatus> instead of
<pvInOtherIOC>, e.g.

field(INP<X>,"<checkStatus> PP")
Perhaps someone can think of a more clever way that does not require
two additional records.
Marty Kraimer

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System