User`s manual

32 Configuring the Agilent E8462A Multiplexer
Initial Operation
You must download the Agilent E8462A SCPI driver into the Agilent
E1405/E1406 Command Module to perform the initial operation.
At power-on or following a reset of the module (
*RST command), all 256
channels are open. A
*RST command invalidates the current scan list (that
is, you must specify a new scan list). Command parameters are set to the
default conditions as shown below.
Execute
SCAN:PORT ABUS to enable use of the analog bus for the SCAN
command. The SCPI driver will then automatically open and close the five
analog bus relays during a scan. A
CLOSe command on a channel will also
automatically close the appropriate tree relays for the given
ROUTe:FUNCtion (see Page 13 "Figure 1-1. Agilent E8462A Simplified
Schematic" ).
Note Do not execute register writes if you are controlling the module by a high
level driver such as SCPI or VXIplug&play. Changing values in registers
with register writes will confuse the driver because it has a record of the
register states after the last command executed by the driver. The driver
record of register states is not updated by a register write, only the register
value is changed. Therefore, the driver will not know the module state.
However, the SCPI driver will re-sync to the hardware if a
CLOSe? query
is executed.
The following example program was developed with the ANSI C language
using the Agilent VISA extensions. The program was written and tested in
Microsoft
®
Visual C++ but should compile under any standard ANSI C
compiler.
To run the program you must have the Agilent SICL Library, the Agilent
VISA extensions, and an Agilent 82340 or 82341 GPIB module installed
and properly configured in your PC. An Agilent E1406 Command Module
is required.
Parameter Default
Value
Description
ARM:COUNt 1 Number of scanning cycles is one.
TRIGger:SOURce IMM Advances through a scanning list
automatically.
INITiate:CONTinuous OFF Continuous scanning disabled.
OUTPut[:STATe] OFF Trigger output from EXT, TTL, or ECL
sources is disabled.
[ROUTe:]FUNC WIRE2 Operating mode is set to WIRE2 at power-
on. This mode is NOT changed by *RST.
[ROUTe:]SCAN:MODE NONE Channel list is not set up.
[ROUTe:]SCAN:PORT NONE Analog bus connections are disabled from
channels.