Re: streamdevice to find the last match

[Dirk Zimoch <dirk.zimoch@psi.ch>]

On 23.08.2013 16:11, Dirk Zimoch wrote:
> Dehong,
>
> I am not sure if the payload data is the first number or the P= number
> or both.
>
> In any case with a %*/.*BOS*/ you should be able to find the last BOS in
> your input. After that start reading your data. If P= is your data it
> would look like this:
>
> in "%*/.*BOS/*d,P=%dEOS\r\n";
Typo.

in "%*/.*BOS/%*d,P=%dEOS\r\n";

> BTW: ExtraInput = Ignore is almost always a bad idea. Use it only if
> absolutely necessary.
>
> Dirk
>
>
> On 23.08.2013 09:55, Dirk Zimoch wrote:
> > Hello Dehong,
> >
> > Is your record "I/O Intr"? I assume so because your STATUS protocol does
> > not have any out command.
> >
> > In that case and if you set InTerminator = CR LF, you should actually
> > get 2 messages and the record should be processed twice. Thus at the
> > end, your record will have the correct value.
> >
> > Skipping intermediate results is tricky on the protocol level, because
> > how should StreamDevice know that no more input is about to come? What
> > if the gap between the messages is sometimes so big, that you actually
> > get 2 messages?
> >
> > But In case you really always get a double message as below and want to
> > read the second value only you can skip the first one:
> >
> > in "BOS%*d,P=%*dEOS\r\nBOS%d,P=%(otherrecord)dEOS\r\n"
> >
> > In case you may have an arbitrary number of messages connected and
> > always want to skip all but the last, things become tricky. I have to
> > make up a PCRE. The idea is to do a greedy search for everything up to
> > "BOS" and then read the data. I will send you the PCRE later.
> >
> > Dirk
> >
> >
> >
> > On 22.08.2013 21:17, Zhang, Dehong wrote:
> > > Hi Dirk and Friends,
> > >
> > > (Sorry if you get this 2 times. I had a wrong address with my previous
> > > send)
> > >
> > > I run into 2 little problems: I wait for the hardware to send a
> > > message like
> > > "BOS123456,P=987654EOS\r\n".
> > > Here BOS is my starting label and EOS the ending label.
> > >
> > > Due to timing, which I cannot control, sometimes I would receive 2
> > > messages
> > > together, like:
> > > "BOS123456,P=987654EOS\r\nBOS345,P=987649EOS\r\n".
> > > Here the first one was sent when the state was still changing, the
> > > second one
> > > was sent when the state stablizes. But the time in between is so short
> > > that the
> > > 2 messages just come out as one. How can I skip the first match, only
> > > get the
> > > second/last match?
> > >
> > > My protocal is like:
> > > InTerminator = CR;
> > > OutTerminator = CR LF;
> > > ReplyTimeout = 800;
> > > ReadTimeout = 100;
> > > WriteTimeout = 100;
> > > ExtraInput = Ignore;
> > >
> > > # Reports from the controller
> > > STATUS { ReplyTimeout = 50; ReadTimeout = 10; InTerminator =; in
> > > "%.1/BOS([0-9,P=]*EOS)/"; }
> > >
> > > I tried to use the "$" anchor, but cannot get it to work -- maybe
> > > because "$" is a special
> > > character in streamdevice.
> > >
> > > Related to this, sometimes the time in between is not so short that
> > > the 2 messages
> > > do come out separately, but the time in between is short enough so
> > > that my stringin
> > > record misses the second message. How can I avoid this? Tune the
> > > ReplyTimeout,
> > > ReadTimeout and InTerminator?
> > >
> > > Thank you for your advice. Best regards,
> > > Dehong