HP 34401A, User Manual

Page: 160 / 236

Using Device Clear to Halt Measurements
Device clear is an
IEEE-488
low-level bus message which can be used to
halt measurements in progress. Different programming languages and
IEEE-488
interface cards provide access to this capability through their
own unique commands. The status registers, the error queue, and all
configuration states are left unchanged when a device clear message is
received. Device clear performs the following actions.
•
All measurements in progress are aborted.
•
The multimeter returns to the trigger “idle state.”
•
The multimeter’s input and output buffers are cleared.
•
The multimeter is prepared to accept a new command string.
For
RS-232
operation, sending the < Ctrl-C > character will perform
the equivalent operations of the
IEEE-488
device clear message.
The multimeter’s
DTR
(data terminal ready) handshake line will be true
following a device clear message. See “DTR/DSR Handshake Protocol,”
on page 151 for further details.
TALK ONLY for Printers
You can set the address to “31” which is the talk only mode. In this
mode, the multimeter can output readings directly to a printer without
being addressed by a bus controller (over either
HP-IB
or
RS-232
).
For proper operation, make sure your printer is configured in the
listen always mode. Address 31 is not a valid address if you are
operating the multimeter from the
HP-IB
interface with a bus controller.
If you select the
RS-232
interface and then set the
HP-IB
address to the
talk only address (31), the multimeter will send readings over the
RS-232
interface when in the local mode.
Chapter 4 Remote Interface Reference
Using Device Clear to Halt Measurements
160