Experimental Physics and
Industrial Control System

From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of "tech-talk at aps.anl.gov" <tech-talk at aps.anl.gov>
Reply-To: "Mooney, Tim M." <mooney at anl.gov>
Date: Thursday, April 8, 2021 at 11:52 AM
To: "tech-talk at aps.anl.gov" <tech-talk at aps.anl.gov>
Subject: StreamDevice mbbi format-converter problem

Dear folks,

I have an mbbi record with streamDevice support, and the following protocol:

get_units { out "REMOTE; CHAN \$1; UNITS?";  in "%{cm|in|%%}"; }

Here is the record definition:

record(mbbi, "$(device):UNITS")

When the device response is "cm" or "in" it is handled correctly, but when the response is "%" the record value doesn't change, even though the asyn trace output shows that the character received actually was "%"

2021/04/08 10:03:28.517 164.54.115.98:4266 write 23

(Three characters are received because the input terminator is "interminator  = CR LF;")

Originally, I had the protocol wrong because I didn't realize the "%" would be treated as a format converter:

get_units { out "REMOTE; CHAN \$1; UNITS?";  in "%{cm|in|%}"; }

But then I tried changing the protocol file to this:

get_units { out "REMOTE; CHAN \$1; UNITS?";  in "%{cm|in|\%}"; }

followed by streamReload(), which didn't work, and finally to this:

get_units { out "REMOTE; CHAN \$1; UNITS?";  in "%{cm|in|%%}"; }

followed by streamReload(), which also didn't work.

I'm using StreamDevice-2-8-9.  I can't figure out what I'm doing wrong.