You might be able to find more about GPIB under the names IEEE488 and HP-IB. It's a 8-bit parallel communications bus used in lab-automation. But it's been like 10 years since I used it so I don't remember the specifics. I once wrote a driver for it under windows 3.0. Most of the communication is indeed human readable ASCII, but there are some extra lines used. On googling I found: "The five interface management lines (ATN, EOI, IFC, REN, SRQ) manage the flow of control and data bytes across the interface" in this document: http://www.techsoft.de/htbasic/tutgpibm.htm?tutgpib.htm
This means that EOI isn't an ASCII character, because it's not transmitted on any of the data lines. You'll probably need to access some specific adress in the GPIB controller, or use it's driver, to get/set the state of the management and the handshake lines. >>>Donn Cave <[EMAIL PROTECTED]> 09/19/05 6:33 pm >>> In article <[EMAIL PROTECTED]>, "Terry Reedy" <[EMAIL PROTECTED]> wrote: >"Madhusudan Singh" <[EMAIL PROTECTED]> wrote in message >news:[EMAIL PROTECTED] >>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, [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
