End or Identify (EOI) character ?
 

Hi

I was wondering how does one detect the above character. It is returned by
an instrument I am controlling via GPIB.

Thanks.

Re: End or Identify (EOI) character ?
 

"Madhusudan Singh" <spammers-go-here@spam.invalid> wrote in message
news:432cb8fd$0$18650$14726298@news.sunsite.dk...
> Hi
>
> I was wondering how does one detect the above character. It is returned
> by
> an instrument I am controlling via GPIB.

EOI = chr(n) # where n is ASCII number of the character.
# then whenever later
if gpid_in == EOI: #do whatever

Terry J. Reedy

Re: End or Identify (EOI) character ?
 

In article <mailman.552.1127021597.509.python-list@python.org>,
"Terry Reedy" <tjreedy@udel.edu> wrote:

> "Madhusudan Singh" <spammers-go-here@spam.invalid> wrote in message
> news:432cb8fd$0$18650$14726298@news.sunsite.dk...
> > Hi
> >
> > I was wondering how does one detect the above character. It is returned
> > by
> > an instrument I am controlling via GPIB.
>
> EOI = chr(n) # where n is ASCII number of the character.
> # then whenever later
> if gpid_in == EOI: #do whatever

Which begs the question, what is the ASCII number of the
character? I was curious enough to feed GPIB and EOI into
a search engine, and from what I got back, I believe it is
not a character, but rather a hardware line that may be
asserted or not. GPIB, whatever that is, may support some
configuration options where EOI causes a character output,
but the actual value depends on configuration. The documentation
is probably the place to find out more about this stuff.

Donn Cave, donn@u.washington.edu

Re: End or Identify (EOI) character ?
 

Hallöchen!

Donn Cave <donn@u.washington.edu> writes:

> In article <mailman.552.1127021597.509.python-list@python.org>,
> "Terry Reedy" <tjreedy@udel.edu> wrote:
>
>> "Madhusudan Singh" <spammers-go-here@spam.invalid> wrote in message
>> news:432cb8fd$0$18650$14726298@news.sunsite.dk...
>>
>>> I was wondering how does one detect the above character. It is
>>> returned by an instrument I am controlling via GPIB.
>>
>> [...]
>
> Which begs the question, what is the ASCII number of the
> character? I was curious enough to feed GPIB and EOI into
> a search engine, and from what I got back, I believe it is
> not a character, but rather a hardware line that may be
> asserted or not.

Right. Well, sometimes there are "termination characters" that
denote the end of a message sent from the intrument to the computer
and vice versa, see
<http://pyvisa.sourceforge.net/pyvisa/node17.html>. They are not
EOI though but \r or \n.

Besides, normally you work on an abstraction level where you don't
worry about the EOI line or any termination characters. For
example, you work with <http://pyvisa.sourceforge.net>. ;-)

Tschö,
Torsten.

--
Torsten Bronger, aquisgrana, europa vetus ICQ 264-296-646

Re: End or Identify (EOI) character ?
 

GPIB is an old established industry standard for hardware control of instruments. It is defined in IEE 488. It evolved from HPIB.
EOI is a character that is sent at the end of a command to show it is the end (over GPIB or RS232 or LAN etc.). The original question was sensible in that the EOI can be different, depending on the instument. It is normally Carriage Return\Line Feed but can be either just CR or LF or something else (LF may be sent as '\n' etc. depends on language and OS)
Instruments I know of that are not standard are Agilent8703 and Agilent E5260. You'd think as the inventors of GPIB (Agilent spun off from HP) they would be standard wouldn't you?