Hi,
I have several questions concerning USBTMC/USB488 protocols and I would
be grateful if someone points me to a more appropriate mail list or
a forum for discussion of these issues.
There is another USBTMC driver written by Stefan Kopp that is suggested
at the Agilent web site. It has a trick with setting End Of File after
every read. It allows e.g. to read the device with /bin/cat or fread(3).
Since usbtmc is a quite special device and the driver discards the data
that does not fit to the read(2) buffer, I consider the trick with EOF
as useful.
I can control a USB488 device and can obtain data from it, but I do not
like that after a typo in a command and an attempt to read the device,
it requires special ioctl's to restore the device state. Is there a way
to check whether some data available for reading?
I have noticed only Message Available (MAV) bit of the status byte
(USB 488 specification, section 4.3.1.3). Unfortunately, it seems that
READ_STATUS_BYTE request has not been implemented in the USBTMC driver.
Actually I am looking for a way to control USB488 devices from a
scripting language. Tcl does not have ioctl at all, python has it, but
I should say that sending the similar commands other a tcp socket is
easier since unavailable data lead just to a timeout.
Thanks.
--
Maxim Nikulin
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