Experimental Physics and
Industrial Control System

According to the streamDevice_version file I seem to have 2.6.

I'll try upgrading it.

thanks so far.

William Kirstaedter (PP&B)
Fritz-Haber-Institut der MPG
Faradayweg 4-6
14195 Berlin
Tel: 030 8413 5405
Mail: [email protected]

Am 14.12.2018 um 09:31 schrieb Dirk Zimoch via Tech-talk:

Hi William,

I tested your template and protocol with several EPICS versions.

3.14.12:
While loading the template, an error is generated:
 Bad Field value  dbPutString received a string that is too long

Can't set "CRYVISIL:LEED:getEN.INP" to "@leed.proto readModule(EN,CRYVISIL:LEED:ENgain,CRYVISIL:LEED:ENoffset,CRYVISIL:LEED:ENvalue,CRYVISIL:LEED:ENmonitorU,CRYVISIL:LEED:ENmonitorI) terminal"

Error at or before ")" in path "."  file "longlink.db" line 4

And then StreamDevice complaines about the link:

2018/12/14 09:19:10.227713 _main_ CRYVISIL:LEED:getEN: Empty I/O link. Forgot the leading '@' or confused INP with OUT or link is too long ? 2018/12/14 09:19:10.227732 _main_ CRYVISIL:LEED:getEN: Record initialization failed

This is expected because of the limitation of EPICS 3.14. But StreamDevice tells you what is wrong.

3.15.5, 3.16.1, 7.0.1:
No problem loading the template.
StreamDevice sees the full link and successfully initializes the record.
Processing the record works.

This is what streamDevice sees of the protocol:

> streamReportRecord CRYVISIL:LEED:getEN

CRYVISIL:LEED:getEN: leed.proto readModule(EN,CRYVISIL:LEED:ENgain,CRYVISIL:LEED:ENoffset,CRYVISIL:LEED:ENvalue,CRYVISIL:LEED:ENmonitorU,CRYVISIL:LEED:ENmonitorI) terminal

active command=none flags=0x0000
readModule {
  extraInput    = error;
  lockTimeout   = 5000; # ms
  readTimeout   = 100; # ms
  replyTimeout  = 1000; # ms
  writeTimeout  = 100; # ms
  pollPeriod    = 1000; # ms
  maxInput      = 0; # bytes
  inTerminator  = "\r";
  outTerminator = "\r";
  separator     = "";

    out "REN";

    in "REN\x0d\x00\x0aEN%(CRYVISIL:LEED:ENgain)f%(CRYVISIL:LEED:ENoffset)f%(CRYVISIL:LEED:ENvalue)f%(CRYVISIL:LEED:ENmonitorU)f%(CRYVISIL:LEED:ENmonitorI)f";

}

Everything is OK.

Maybe you are using an older version of StreamDevice, where the buffers were still limited to 80 chars?

The current version 2.8.8 is available here:
https://github.com/paulscherrerinstitute/StreamDevice

Dirk


On 13.12.2018 14:56, Dirk Zimoch via Tech-talk wrote:

Hi William,

Even though the INP Length in EPICS 7 is not unlimited, StreamDevice may nor be able to read it. 78 bytes was the effective limit of INP/OUT in EPICS 3.14. Meanwhile I have changed my buffers from 80 to 256 bytes but not yet to "unlimited" (which is a bigger change).

However your string is cur at 78 chars like in EPICS 3.14.

I will check this with EPICS 7....

Dirk

On 13.12.2018 09:46, William Kirstaedter via Tech-talk wrote:

unlimited cant be the case, unfortunately. I'm running EPICS7 and facing the following error when starting the IOC:

2018/12/13 09:42:51.409543 _main_ Missing ')' after substitutions 'readModule(EN,CRYVISIL:LEED:ENgain,CRYVISIL:LEED:ENoffset,CRYVISIL:LEED:ENvalue,LEED_01' 2018/12/13 09:42:51.409621 _main_ CRYVISIL:LEED:getEN: Protocol parse error 2018/12/13 09:42:51.409642 _main_ CRYVISIL:LEED:getEN: Record initialization failed

with these records and streamprotocol:

# Energy
record(stringin, "$(P):$(R):getEN") {
field(DTYP,"stream")

field(INP,"@leed.proto readModule(EN,$(P):$(R):ENgain,$(P):$(R):ENoffset,$(P):$(R):ENvalue,$(P):$(R):ENmonitorU,$(P):$(R):ENmonitorI) $(PORT)")

}
record(ai, "$(P):$(R):ENgain") {
field(DESC,"Energy Gain")
field(EGU,"eV")
field(PREC,"2")
}
record(ai, "$(P):$(R):ENoffset") {
field(DESC,"Energy Offset")
field(EGU,"eV")
field(PREC,"2")
}
record(ai, "$(P):$(R):ENvalue") {
field(DESC,"Energy Value")
field(EGU,"eV")
field(PREC,"2")
}
record(ai, "$(P):$(R):ENmonitorU") {
field(DESC,"Energy Voltage Monitor")
field(EGU,"eV")
field(PREC,"2")
}
record(ai, "$(P):$(R):ENmonitorI") {
field(DESC,"Energy Current Monitor")
field(PREC,"2")
field(EGU,"A")
}
------------
OutTerminator= CR;
InTerminator= "\r\000\n>";
readModule{
# $1 : Module Name -> REN (read energy)
out"R\$1";

# answer: R $1 r NUL n $1 (what out "typed in" plus return) $1|SP|GAIN|SP|OFFSET|SP|VALUE|SP|U-monitor|SP|I-monitor (the actual answer)

# >REN
# EN +0 +500 +500 +500.85 +1.5653E-06
in"R\$1\r\000\n\$1%(\$2)f%(\$3)f%(\$4)f%(\$5)f%(\$6)f";
}

William Kirstaedter (PP&B)
Fritz-Haber-Institut der MPG
Faradayweg 4-6
14195 Berlin
Tel: 030 8413 5405
Mail:[email protected]

Am 12.12.2018 um 17:29 schrieb Johnson, Andrew N.:

On 12/12/18 8:59 AM, William Kirstaedter via Tech-talk wrote:

Short Question:

Whats the maximum length of a record field? how many chars?

record(ai,"record_name"){

    field(DESC, "I_mean_this")
    field(INP, "how_long_can_this_be")

}

Longer answer:

That depends on the field definition for the record type. DESC is defined in dbCommon.dbd  (a kind of super-class used by all record types) as:

        field(DESC,DBF_STRING) {
                prompt("Descriptor")
                promptgroup("10 - Common")
                size(41)
        }

That means it's a DBF_STRING and the size() entry says it can hold up to 41 characters, but there must be a zero-byte terminator so the limit is really 40 (which matches the Channel Access dbr_string_t typedef).

For something like the ZRST field of the mbbi record which defines an enumeration string, the size is given as 26 which is the size of the enumeration strings that Channel Access can send in a struct dbr_gr_enum.

An INP or OUT field is a link and for these the maximum length depends on the version of EPICS you're running; it might be 40 for older versions, 80, 256 for some or unlimited for EPICS-7.

HTH,

- Andrew
--
Arguing for surveillance because you have nothing to hide is no
different than making the claim, "I don't care about freedom of
speech because I have nothing to say." -- Edward Snowdon

----------------------------------------------------------------------
Das FHI verarbeitet, speichert und loescht Daten im Rahmen seiner
Geschaeftstaetigkeit gemaess der Datenschutz-Grundverordnung (DSGVO)
[General Data Protection Regulation (GDPR)] der Europaeischen Union.

References:

record field max length? William Kirstaedter via Tech-talk

Re: record field max length? Johnson, Andrew N. via Tech-talk

Re: record field max length? William Kirstaedter via Tech-talk

Re: record field max length? Dirk Zimoch via Tech-talk

Re: record field max length? Dirk Zimoch via Tech-talk

Navigate by Date:

Prev: Re: record field max length? Dirk Zimoch via Tech-talk

Next: Re: record field max length? Dirk Zimoch via Tech-talk

Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  <2018>  2019  2020  2021  2022  2023  2024 

Navigate by Thread:

Prev: Re: record field max length? Dirk Zimoch via Tech-talk

Next: motor R6-11 released Peterson, Kevin M. via Tech-talk

Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  2017  <2018>  2019  2020  2021  2022  2023  2024