Experimental Physics and
Industrial Control System

Ralph Lange <[email protected]> · Fri, 20 Feb 2009 10:51:43 +0100

Good points.

I didn't think about external CA links, though.

As nowadays using CA/CP links is the only way to link records without

forcing them into the same lock set, it's a pity that this doesn't work

for PINI processing.

Idea: Why not introduce an additional PINI sweep, and change the PINI

field to be a three-option choice?

"NO", "YES", "UP": NO and YES yield the classical behaviour, while "UP"

puts the record into the second PINI phase, that runs *after* the CA

client and server are started (I.e., when the IOC is UP).

Should be compatible, shouldn't break existing stuff, allows CA/CP in

PINI processing.

For the Redundant IOC , it has the interesting side effect that you can

select if the record should be processed at boot time, or after the IOC

has become active.

(If the IOC switches back and forth between active and inactive, would

UP records be processed whenever it gets active? Do we need to

distinguish between "Once UP" and "Whenever UP"?)

Ralph

On 18.02.2009 16:59 Andrew Johnson wrote:

On Wednesday 18 February 2009 06:56:57 Ralph Lange wrote:

This sounds like a fix could be feasible and/or an issue on Andrew's
list, doesn't it?

Unfortunately I just realized that doing so would break the Redundant IOC

interface. Those xxxRun() calls are in iocRun() whereas the initialProcess()

call is in iocBuild(), so in a redundant IOC the PINI processing happens at

start-up but the CA links don't get connected until the redundancy executive

says "go" (which could be weeks or even months later). I'm not sure if the

initialProcess() call could/should be moved, but doing so would change the

meaning of some of our initHooks.

The other thing that worries me is that I think the act of connecting up the

CA links probably also enables any CP or CPP input links to start processing,

so it's possible that they could pre-empt the PINI processing (especially if

they're pointing at an external IOC which is already running).

- Andrew

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System