Experimental Physics and Industrial Control System
At the last collaboration meeting (during ICALEPCS) there was a
lengthly discussion during Jeff's talk on the "Portable CA Server
status" that dealt with the relationship between CA, PCAS, and cdev.
I recall a statement being made that the functionality of the CA
client API may be reduced in future releases (4.0+?) under the
assumption that most client applications will be using a cdev layer to
reach CA.
Does this still reflect current thinking? I'm interested since I may
have to interface an existing system with one under development that
uses CA (and possibly cdev).
Also during the discussion, the following table of implementation cases
was drawn up - although this only covers the generalities.
Case/Implementation: New Service/PCAS
Server I/F: PCAS + I/F to PCAS (database-like)
Client I/F: CA
Notes: only needs server I/F to PCAS.
Case/Implementation: New Service/cdev
Server I/F: new connection management layer (CA-like)
Client I/F: cdev + cdev service layer
Notes: coding required for both client and server
Case/Implementation: Old Service/PCAS
Server I/F: old service + new I/F to PCAS (database-like)
Client I/F: CA
Notes: subject to constraints of CA API
Case/Implementation: Old Service/cdev
Server I/F: old service
Client I/F: cdev + cdev service layer
Notes: only needs cdev service layer
The conclusions drawn from the above discussion seemed to be that
1) it's simpler to interface a new service to PCAS (and use the CA +
cdev? on the client side), but
2) it's simpler to interface an old service to cdev.
Aloha,
Peregrine
-------------------------------------------------------------------------------
Peregrine M. McGehee http://www.cfht.hawaii.edu/~mcgehee
Telescope Control Systems Group Canada-France-Hawaii Telescope
(808) 885-3178 P.O. Box 1597, Kamuela, Hawaii 96743
- Replies:
- Re: CA API: Future directions? Jeff Hill
- Navigate by Date:
- Prev:
Re: Capfast 3.02.23 and CALC records Nick Rees
- Next:
Re: New GPIB docs on line!!! John R. Winans
- Index:
1994
1995
<1996>
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
- Navigate by Thread:
- Prev:
Re: Capfast 3.02.23 and CALC records Nick Rees
- Next:
Re: CA API: Future directions? Peregrine McGehee
- Index:
1994
1995
<1996>
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024