Table of Contents
Advertisement
Model 2790 SourceMeter
System channel operation (7702 only)
klqb
The system channel is a closed measurement channel that is internally connected to the
internal DMM Input of the Model 2790. The system channel number is displayed on the
Model 2790. For a 4-wire function (i.e., Ω4), the paired channel for the system channel is
internally connected to DMM Sense. The paired channel is not displayed on the
Model 2790. When triggered, the DMM performs a measurement and displays it on the
Model 2790.
The system channel is selected by closing a measurement channel using the system channel
close keys. These include the
See
"Controlling the system channel," page
Other important points about system channel operation include the following:
•
•
•
•
klqb
2-wire functions
Figure 2-1
of the Model 2790. Assume a Model 7702 switching module is installed in slot 2 of the
mainframe. When channel 201 is closed using the system channel close keys, both the
Channel 1 relay and the backplane isolation relay (Channel 45) close to connect the chan-
nel to the DMM. The complete simplified schematic of the Model 7702 is provided in
Figure
®
Switch System Reference Manual
System channel operation only applies to the Model 7702 switching module. If
not using a 7702 in your test system, you can skip this topic.
There can only be one system channel. This is the 7702 channel that is presently
displayed (and closed) on the Model 2790. When a channel is not displayed, there
is no system channel.
When a measurement channel is closed, the input backplane isolation channel also
closes to connect the system channel to DMM input. For a 4-wire function, the
paired channel and the sense backplane isolation channel also close to make the
sense connections to the DMM.
When a different measurement channel is closed, the previous system channel
opens. The newly closed (and displayed) measurement channel becomes the
system channel.
The system channel close keys can only close measurement channels that will
automatically connect to the DMM. Non-measurement channels cannot be closed
by the system channel close keys.
Use the VIEW option of the CARD menu to display all closed channels in the
mainframe (see
"CARD menu," page
shows an example of how the system channel is connected to the DMM Input
2-13.
and
keys or the CLOSE key (SINGLE menu option).
2-9, for details.
2-26).
2-7
Advertisement
Table of Contents
