RE: Streams format converters question ( how to convert 10100 to 1.0E+00, 10011 to 1.0E-11)

[Zimoch Dirk via Tech-talk <tech-talk at aps.anl.gov>]

Hi Susheng

 

Nice format. People always invent something new.

 

I would try to pre-process the format with regular _expression_ substitution (%#/regex/subs/) so that it fits the normal %f format.

 

We need to keep one digit, then insert a period dot, then take the next digit, insert an “e”, convert a 0 to a – and a 1 to a + and then copy the next two digits. The sign magic is the nasty part.

 

This may do the trick: (I have not tested it yet)

 

in "%#/([0-9])([0-9])0([0-9][0-9])/\1.\2e-\3/%#/([0-9])([0-9])1([0-9][0-9])/\1.\2e+\3/%f";

 

Output too?

 

 

From: Tech-talk <tech-talk-bounces at aps.anl.gov> On Behalf Of Peter Sx via Tech-talk
Sent: Donnerstag, 27. März 2025 14:54
To: tech-talk at aps.anl.gov
Cc: sxin at bnl.gov
Subject: Streams format converters question ( how to convert 10100 to 1.0E+00, 10011 to 1.0E-11)

 

Hi EPICS Specialists:

 

I've run into a problem converting data to exponential readings. I have a device that outputs messages and data in the same channel. I have separated the readings from messages with data by using the following records and protocol. 

I am wondering whether I can add some arguments in the protocol and convert the data through calcout, but I am new to Streams and can't figure out the details.

Data format:  ppsee (p.p * 10see):

Symbols   Description

pp        Mantissa of the reading (1.0 to 9.9)

s         Sign of the exponent (0 = negative, 1 = positive)

ee        Exponent (00 to 11)

record(ai, "$(Sys)$(Dev)Ch1_Reading")
{
    field(DESC, "Ch1 Reading")
    field(DTYP, "stream")
    field(INP, "@Televac.proto get_Ch1_reading($(Sys)$(Dev)Ch1message) $(PORT)")
    field(SCAN, ".1 second")
}
record(stringin, "$(Sys)$(Dev)Ch1message")
{
}

 

get_Ch1_reading {
    out "S101";
    in "%f";
    @mismatch {in "%(\$1)39c";}
}

Current channel readback examples:

[sxin@eic-905-pc01 ~]$ caget 905-HC1-Televac:Ch5_Reading    device panel reading 1.0E-11
905-HC1-Televac:Ch5_Reading    10011
[sxin@eic-905-pc01 ~]$ caget 905-HC1-Televac:Ch6message   
905-HC1-Televac:Ch6message     OFF

Thank you!

Susheng