© National Instruments
|
B-5
GPIB-140A User Manual
Case 2: Talker Is HS488-Capable, But Listener Is Not
HS488-Capable
Figure B-4 and the following steps describe a typical sequence of events in an HS488 data
transfer in which the Talker is HS488-capable, but the Listener is not.
Figure B-4.
HS488-Capable Talker
Steps 1-6 are identical to steps 1-6 in
Case 1: Talker and Listener Are HS488-Capable
. The
Listener ignores the HSC message from the Talker.
Then, the IEEE 488.1 Listener enters ACDS and asserts NRFD. As a result, the Talker
determines that the addressed Listener is not HS488-capable. The Talker sources bytes using the
IEEE 488.1 protocol.
Low-going tr
a
n
s
ition on ~NRFD
indic
a
te
s
th
a
t not
a
ll receiving
device
s
a
re high-
s
peed c
a
p
ab
le.
High-
s
peed c
a
p
ab
le
s
ign
a
l
~ATN
~DIO1
8
(compo
s
ite)
~DAV
~NFRD
~NDAC
T1
