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<== Date ==> <== Thread ==>

Subject: Re: CSS Boy Write PVs to file
From: "Konrad, Martin" <[email protected]>
To: Kay Kasemir <[email protected]>
Cc: "[email protected]" <[email protected]>
Date: Thu, 22 Sep 2016 12:57:46 +0000
Hi Kay,
> The PV needs to connect. If you get the value right away, you’ll
> receive a null because the PV has not connected and not received the
> initial value, yet.
Thanks for clarifying. So this makes it a bit more unpredictable than I
thought... Waiting thus might not be reliable :-(

> Overall, performing logic like data acquisition should not be handled
> in the user interface.
There are a couple of use cases that do not require any complex logic.
For example saving a snapshot of a waveform PV into a file. For many use
cases it makes more sense to save this file to a client machine.
Example: Reading/writing firmware via waveform PVs. The FPGA engineer
might not even have access to the IOC's file system...

> Better would be to add a listener to the PV which gets notified as 
> values arrive.
Sounds reasonable. Can you point us to an example/documentation?

Thanks,

Martin

-- 
Martin Konrad
Control System Engineer
Facility for Rare Isotope Beams
Michigan State University
640 South Shaw Lane
East Lansing, MI 48824-1321, USA
Tel. 517-908-7253
Email: [email protected]


Replies:
RE: CSS Boy Write PVs to file Iain Marcuson
References:
Re: CSS Boy Write PVs to file Konrad, Martin

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