S Mode Functions
Chapter 5
GPIB-232CT User Manual
5-38
© National Instruments Corp.
rsp - Request (Conduct) a Serial Poll
Type:
Serial Poll function
Syntax:
rsp
alist
<CR>
Purpose:
You
use
rsp
if you wish to conduct a serial poll to obtain
device-specific status information from one or more devices.
Remarks:
The
argument
alist
is a list of
addrs
that are separated by
commas or spaces.
addrs
are device addresses that specify
the GPIB addresses you wish to poll.
A device address consists of a primary address and an
optional secondary address. The secondary address is
separated from the primary address by a plus sign (
+
).
Only the lower five bits of each address are significant. These
bits can be in the range from 0 through 30 for both the
primary and the secondary addresses. Therefore, the binary
value 01100010 (decimal 98) is interpreted as decimal 2.
The following examples all specify a primary address of 0 and
a secondary address of 2. The listen address is 32, the talk
address is 64, and the secondary address is 2 or 98, which are
equivalent.
0+2
or
0+98
or
32+98
or
0+\x62
rsp
serially polls the specified devices to obtain their status
bytes. If bit 6 (the hex 40 or RQS bit) of a device's response
is set, its status response is positive; that is, that device is
requesting service. Before
rsp
completes, all devices are
unaddressed.
The interpretation of each device's response, other than the
RQS bit, is device specific. For example, the polled device
might set a particular bit in the response byte to indicate that it
has data to transfer, and another bit to indicate a need for
reprogramming. Consult the device documentation for
interpretation of the response byte.
