Experimental Physics and
Industrial Control System

"Zhang, Dehong" <[email protected]> · Thu, 22 Aug 2013 12:17:37 -0700

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

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System