Re: problem in communicating to the gpib device with asyn4-6

[Eric Norum <norume@aps.anl.gov>]

On Aug 3, 2007, at 10:25 PM, zhangdemin99 wrote:

> dear Norum,
>   Tanks for your reply.
>   I have set like what you suggested:
> {&DSET_SO,GPIBWRITE,IB_Q_LOW,NULL,"DISP:TEXT \"%s\"",0,200,NULL, 
> 0,0,NULL,NULL,NULL}
> {&DSET_SI,GPIBREAD,IB_Q_LOW,"DISP:TEXT?","%39[^\r\n]",0,200,NULL, 
> 0,0,NULL,NULL,NULL}
>   asynOctetSetInputEos("L0",-1,"\LF")
>   asynOctetSetOutputEos("L0",-1,"\LF")
>
> but there are also some problems:
> epics>2007/08/04 10:18:38.879 /dev/ttyS0 write 18
> DISP:TEXT \"abcd\"L
> epics>2007/08/04 10:18:45.263 /dev/ttyS0 write 11
> DISP:TEXT?L
> 2007/08/02 10:18:50.266 display-query read status ""nin 0
> 2007/08/02 10:18:50.266 display-query error.
>
> At the same time ,thanks Mayssat for your suggestion.
> I am sure the message terminators for the device are"LF".

I think that there may be a language problem here.  It is quite  
likely that the terminator for your device is a single <linefeed>  
character.  The documentation probably refers to this as LF and you  
are making the assumption that the terminator is literally 'LF'.

Try changing the end-of-string commands to the following and see what  
happens:
  asynOctetSetInputEos("L0",-1,"\n")
  asynOctetSetOutputEos("L0",-1,"\n")


> Demin Zhang
>
>
> 劲 爆 150 万 同 时 在 线，众 人 追 捧 梦 幻 西 游

--
Eric Norum <norume@aps.anl.gov>
Advanced Photon Source
Argonne National Laboratory
(630) 252-4793