Experimental Physics and Industrial Control System
Hi all,
As part of the "ca.py - Throws error - workaround" thread there was some
discussion whether a CA client should call ca_clear_subscription when it
detects that a server has disconnected and presumably re-subscribe when
the server re-connects.
Although the CA library automatically maintains the subscription, wouldn't
it be better that when the PV re-connects, the client should do a ca_get
(or ca_get_array or ca_get_array_callback) and a new ca_create_subscription.
I would do this because the nature of a PV might have changed and a new
ca_get would ensure that the client has the latest associated data
(e.g. precision, EGU, enumeration values), and a new subscription because
the field type and/or number of elements may have changed as well.
Although such PV changes are relatively rare, they do occur.
Any counter arguments?
--
Andrew Starritt | Principal Controls Engineer | Australian Synchrotron
p: (03) 8540 4164 | f: (03) 8540 4200
[email protected] | www.synchrotron.org.au
800 Blackburn Road, Clayton, Victoria 3168
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