Re: record field max length?

[William Kirstaedter via Tech-talk <tech-talk@aps.anl.gov>]

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: kirstaedter@fhi-berlin.mpg.de

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:kirstaedter@fhi-berlin.mpg.de
> > >
> > > 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

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