Keysight E1412A, Руководство пользователя и руководство по программированию SCPI, Страница: 22 / 243

xxii Keysight E1412A Digital Multimeter User Guide
Keysight E1412A Multimeter Module Setup Interrupt Priority
Interrupt Priority
The E1412A Multimeter is a VXIbus interrupter. However, there is no interrupt
priority level setting to be made on the module. Interrupt priority level, setup,
and activation are configured on the resource manager which is the interface to
the VXIbus and contains any instrument drivers required to communicate with a
VXI module. Your resource manager could be a VXI command module,
embedded PC controller, the PC-based VXLink Interface (ISA-to-VXI), the Series
700 workstation VXI-MXIbus interface or another VXI controller. To configure the
interrupt priority on the E1405B and E1406A Command Modules, you would use
the
DIAGnostic:INTerrupt command subsystem. Refer to your resource manager's
documentation for information on setting the system's interrupt priority.
Setting the Line Frequency Reference
You must set the line frequency reference to the line frequency of the power
source to your mainframe for maximum normal mode rejection (NMR). NMR is
the multimeter's ability to reject power line frequency noise in a DC voltage or
ohms measurement. You should set the multimeter's line frequency reference to
the exact power line frequency (50, 60 or 400Hz). Failure to set the line
frequency reference to that of your source will cause reading errors.
You use the CALibration:LFRequency command to set the line frequency
reference. The default setting at power-on is 60Hz. If you use 50Hz or 400Hz you
need to set the line frequency reference for maximum NMR. Specifying 400Hz
actually sets the line frequency reference to 50Hz since 50Hz is a sub harmonic
of 400Hz. Executing a
CALibration:LFRequency? will return
+50
after executing
CAL:LFR 400 to set the line frequency reference to 400Hz.
The line frequency reference setting is also useful when the device being
measured operates at a different frequency than the multimeter. For example, if
the multimeter has a power line frequency reference of 60Hz and the device
being measured has a power line frequency of 50Hz, maximum NMR is achieved
by setting the multimeter's reference frequency to 50Hz by executing:
CAL:LFR 50
Checking the Line Frequency Reference
The CALibration:LFRequency? command returns the present setting of the power
line frequency reference. The command returns
+50
or
+60
. For a setting of
400Hz,
+50
is returned since 50Hz is a sub harmonic of 400Hz.