Re: streamdevice and input strings

[Maren Purves via Tech-talk <tech-talk at aps.anl.gov>]

Thank you Dirk.

Still being stuck in the days of drvascii/drvserial we just went to
reading devices that returned a few values by format, like skip until
you get to here, read that, and skip the rest. That may work with asyn
as well if you're not expecting too many values or at too fast a rate.
For us it was/is mostly the weather station.
I'm glad things have moved forward from that even if I am unlikely to
get to that here.

Aloha,
Maren

On Tue, Apr 16, 2024 at 7:26 PM Zimoch Dirk via Tech-talk
<tech-talk at aps.anl.gov> wrote:
>
> Hello Pierrick,
>
> StreamDevice uses Separator only for array records (waveform, aai, aao). There, it reads alternating the format and the separator. But the format %s only stops at a space, not at your separator. Thus, the first %s gets the complete string and there is no separator left to read. Here, with redirections to multiple scalar records, the Separator is not used at all. Still the %s consumes as much as it can, that is everything.
> What you need is %[^,] instead of %s (that reads strings up to comma) and explicit commas in between:
> in  "%(\$1:G1Name)[^,],%(\$1:G2Name)[^,], %(\$1:G3Name)[^,],%(\$1:G4Name)[^,]";
>
> Also, one of the formats (I suggest the last) can be without redirection if the corresponding G*Name record (G4 in this case) is the one which calls this protocol.
>
> Best regards,
> Dirk
>
> > Am 17.04.2024 um 01:24 schrieb Pierrick M Hanlet via Tech-talk <tech-talk at aps.anl.gov>:
> >
> > Hi all,
> > I'm on a linux box with AL9.3, base 7.07, and StreamDevice 2.8.24.
> > I have a string input, which the controller gives as: A1,A2,B1,B2.
> > I want to read them individually as separate names, i.e. separate records.
> >
> > My protocol is:
> > get_names {
> >     separator=",";
> >     out "CID";
> >     in  "%(\$1:G1Name)s%(\$1:G2Name)s%(\$1:G3Name)s%(\$1:G4Name)s";
> > }
> >
> > although, I've also tried as:
> > get_names {
> >     separator=",";
> >     out "CID";
> >     in "%(\$1:G1Name)s,%(\$1:G2Name)s,%(\$1:G3Name)s,%(\$1:G4Name)s";
> > }
> >
> > or as:
> > get_names {
> >     out "CID";
> >     in "%(\$1:G1Name)s,%(\$1:G2Name)s,%(\$1:G3Name)s,%(\$1:G4Name)s";
> > }
> >
> > Of course, it works perfectly if I have:
> > get_names {
> >     out "CID";
> >     in "%(\$1:G1Name)2c,%(\$1:G2Name)2c,%(\$1:G3Name)2c,%(\$1:G4Name)2c";
> > }
> > However, the name can be up to 8 characters long.
> >
> > I don't understand why separator doesn't work as I'm using it.
> > Thank you,
> > Pierrick
> >
> >
> > --
> > Pierrick Hanlet
> > Fermi National Accelerator
> > Accelerator Front End Controls
> > +1-630-840-5555 -- lab
> > +1-312-687-4980 -- mobile
> >
> > "Whether you think you can or think you can't, you're right" -- Henry Ford
> >