Dual Independent Multiplexers (7702 Only) - Keithley SourceMeter 2790 Reference Manual

Model 2790 SourceMeter

Dual independent multiplexers (7702 only)

klqb
Using multiple channel operation, the 7702 module can be configured as two independent
multiplexers. The 7702 is normally used as a single 1 × 40 multiplexer, but it can also be
configured as two 1 × 20 multiplexers.
The 7702 module is configured as two multiplexers by using multiple channel operation to
close the 2-pole/4-pole relay. The 7702 is configured as two independent multiplexers by
closing channel 43. As shown in
Multiplexer A (channels 1 through 20) from Multiplexer B (channels 21 through 40).
For the dual multiplexer configuration, only Multiplexer A channels can be internally con-
nected to the DMM of the Model 2790. Closing channel 45 allows channels 1 through 20
to be measured by the DMM.
When using the dual multiplexer configuration, the sense backplane isolation relay (chan-
nel 44) must be kept open to isolate Multiplexer B channels from the sense terminals of
the DMM
Figure 2-8
Dual multiplexer configuration (7702)
Multiplexer A
(1x20)
Multiplexer B
(1x20)
®
Switch System Reference Manual
The following discussion only applies to the 7702 switching module. If not using
a 7702 in your test system, you can skip this topic.
(Figure 2-8).
HI
Ch 1
LO
Channels
2–19
HI
Ch 20
LO
HI
Ch 21
LO
Channels
22–39
HI
Ch 40
LO
Figure 2-8, the closed position of channel 43 isolates
Ch 45
Ch 43
(Closed)
Ch 44
For the dual multiplexer configuration,
Ch 43 must be closed and Ch 44 must
remain open.
2-21
HI
Input
LO
To
Model 2790
DMM
HI
Sense
LO