StreamDevice mbbi format-converter problem

["Mooney, Tim M. via Tech-talk" <tech-talk at aps.anl.gov>]

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")

{

    field(DESC, "Units")

    field(DTYP, "stream")

    field(INP,  "@cryomagLM510.proto get_units($(chan)) $(port)")

    field(ZRST, "cm")

    field(ONST, "in")

    field(TWST, "%")

    field(SCAN, "Passive")

}

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

REMOTE; CHAN 1; UNITS?

2021/04/08 10:03:28.617 164.54.115.98:4266 read 3

%

(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.

Tim Mooney (mooney at anl.gov) (630)252-5417
Beamline Controls Group (www.aps.anl.gov)
Advanced Photon Source, Argonne National Lab