Enabling Local Control; Triggering Devices - HP 9000 Series 300 Tutorials Manual

Enabling Local Control
During system operation, it may be necessary to place certain devices in
local state for direct operator control such as when making special tests or
troubleshooting. The GO TO LOCAL command returns all devices currently
addressed as listeners to their local state.
For example, the following code segment places devices at bus addresses 3 and
5 in local state.
command[O]
=
63;
command[1]
=
32
+
3;
command[2]
=
32
+
5;
command[3]
=
1;
hpib_send_cmnd{eid.
Triggering Devices
1*
the UNLISTEN command*1
1*
listen address for device at address
3*1
1*
listen address for device at address
5*1
1*
the GO TO LOCAL command*1
command. 4);
The HP-IB TRIGGER command tells devices currently addressed as
listeners
to
initiate some
device-d~p~iident
action. A typical use is triggering
a measurement cycle on a digital voltmeter. Since device response to a
TRIGGER command is strictly device-dependent, HP-IB has no direct control
over the type of action being initiated.
The following code triggers the device at bus address 5:
command[O]
=
63;
1*
UNLISTEN command*1
command[1]
=
32
+
5;
1*
listen address for device at address
5*1
command[2]
=
8;
1*
TRIGGER command*1
hpib_send_cmnd{eid. command. 3);
3-26 Controlling the HP-IB Interface