Experimental Physics and
Industrial Control System

Hinko Kocevar <[email protected]> · Mon, 17 Sep 2012 19:07:54 +0200

Hi Andrew,

On 09/17/2012 05:12 PM, Andrew Johnson wrote:

Hi Hinko,

On 2012-09-17 Hinko Kocevar wrote:

If I understand the use of aSub correctly, it does not need allow DTYP
being set. Since I can't bind any device to it, I was hoping that INPx
field(s) might be set to point to INST_IO based link type, something like :

Sorry, I didn't realize you were using the waveform for I/O as well; in that
case you probably still need the waveform record.

No problem, at least I know how is aSub supposed to be used.

@param(PARAM1=abc PARAM2=123)

but that does not seem to work as expected. The problem I see when
trying to get link value (this is from init() at IOC startup):

rec->inpa.value.instio.string ==>> '@param(PARAM1=abc'

   ONLY half of string.. where is the other half?

You can't do that.  The code must look at the inpa.type field before examining

I can do inpa.type field check too.. but I guess that EPICS code does

its part in determining what the input link should be, before I can get

to its value first.

Does this mean that my INP link value was modified or its just that I'm

not looking at the right place?

Another thing I could bo is change the format of @param() not to include

spaces :)

Will I still in the "you can't do that" zone?

OTOH, since these parameters are meant for the device, I'll probably

resort to an extra "info" field added to the records, that will hold my

@param. With other standard records like ai, bi, ao, bo I could store

this info into INP/OUT field and got away with it, so I was hoping this

holds true for aSub too.

You'll have to read in the array from the waveform using an INP link, process
it, then output it again using an OUT link.

Since we are on the subject of aSub, I was planning on using it for some

other types of data, that would not require INPx links at all - is this

doable?

For that case, all I need is for data to be seen on the OUTx links. What

I was planning to do is, update the outx members of aSub with the data

read from the the device - this would be done in process(). This way I

actually do not need INPx and corresponding waveform records that would

serve INPx. Why I want to avoid waveforms? To avoid copying data from

one buffer to another, since the instrument is quite complex and capable

of providing large amounts of data at high rates (> 100 Hz). Every CPU

cycle wasted, is sought for ..

I'll test the stuff above myself, but I also want to know how my

solution complies with the EPICS way of doing things.

Thanks,
Hinko

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System