Keithley 2700, User Manual, Page: 61 / 500

2-6 Close/Open Switching Module Channels Model 2700 Multimeter/Switch System User’s Manual
System channel operation
The system channel is a closed measurement channel that is internally connected to the
internal DMM Input of the Model 2700. The system channel number is displayed on the
Model 2700. For a 4-wire function (i.e.,
Ω
4), the paired channel for the system channel is
internally connected to DMM Sense. The paired channel is not displayed on the
Model 2700. When triggered, the DMM performs a measurement and displays it on the
Model 2700.
The system channel is selected by closing a measurement channel using the system
channel close keys. These include the
and keys, or the CLOSE key (SINGLE menu
option). See “Controlling the system channel,” page 2-9 , for details.
Other important points about system channel operation include the following:
• There can only be one system channel. This is the channel that is presently
displayed (and closed) on the Model 2700. 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.
NOTE
Use the VIEW option of the CARD menu to display all closed channels in the
mainframe (see
“CARD menu,” page 2-29 ).