25 Feb
2007
25 Feb
'07
12:41 p.m.
Tony Duell wrote:
Is this docuemtned anywhere? I can't see it in the 9872 operating/service
manual, but as I said I've not seen the 98130 (9815 plotter interface)
manual.
My guess, and it's only a guess, is that it
works something like this :
At power-up, if the 9815-mode line is asseeted, the plotter goes into
^^^^^^^^^
listen mode (the HPIB talk/listen modes can be
controlled from the
^^^^^^^^^^^ ^^^^
plotter's microcontroller, this is also used
for self-tests on the HPIB
interface, as it is on the 7245...). The 9815 talks and sends it data.
^^^^^ ^^^^^ ^^^^
If the poltter gets a command that should output
data (say a digitise
command), it goes into talk mode automatically and sends said data. The
^^^^ ^^^^ ^^^^^^^^^^^^^ ^^^^^ ^^^^
9815 side of things knows it's just sent such
a command and goes into
listen mode to recieve said data.
^^^^^^^^^^^ ^^^^^^^ ^^^^
Good for you, you've finally got it. As I said previously: un-addressed talk/listen
HPIB-style data transfer.
HPIB-style, but not HPIB!. It may use the HPIB lavels, it may use the
same 3 wire handshake, but it's not HPIB if it changes direction like
that without any commands fromt he controller. That's what confused me.
You kept on insisting it was HPIB, I still claim that, strictly, it can't be.
-tony