Re: Process aSub record on arrival of data

[Ralph Lange via Tech-talk <tech-talk at aps.anl.gov>]

On Thu, 27 Jul 2023 at 21:24, Andrew Johnson via Tech-talk <tech-talk at aps.anl.gov> wrote:

Hi Matt,

On 7/27/23 1:33 PM, Matt Rippa via Tech-talk wrote:

I have 2 aSub records: Tx on IOC  A and Rx on IOC B.

IOC A and B are on different machines on my network.

I want Tx to send an array to Rx over CA (or PVA). Once the data arrives is there a stock method to trigger Rx to process? IIUC, using the CPP attribute in Tx.OUTA will not cause the Rx to process since these records are on different IOC's. I'm using another OUT link in Tx to write to Rx.PROC.

Is that the most efficient way to do this?

The standard and most efficient way would be to have RX.INPA be a CA link to the TX.VALA field with the CPP link flag set, then every time TX updates its VALA field the CA monitor event will update the RX.A array and process that record immediately. If you want to make that processing conditional there are a couple of different ways to do that, but that's a different question for a different email.

Another advantage of this "monitor" style is that the receiving end Rx gets notified when the connection to Tx on IOC A goes down.

Writing data from Tx in "push" style is a fire-and-forget operation: neither side is notified if it fails.

Proper error handling for such setups is yet another question for yet another mail.

Cheers,
~Ralph