Keithley 7021 Instruction Manual page 24

Figure 2-11 shows an example of input expansion. Each
Model 7021 card is configured with dual 1 × 12 and 1 × 18
multiplex banks. By connecting the banks together (via the
Model 7001/7002 analog backplane), the resultant multi-
plexer system has 24 inputs for bank A and 36 inputs for
bank B. Notice that if all the bank-to-bank jumpers (for both
cards) were installed, the result would be a single 1 × 60
multiplexer.
Mixing card types
Different types of cards can be used together to create some
unique switching systems. For example, you could have a
Model 7021 multiplexer-digital I/O card installed in one slot
and a Model 7022 matrix-digital I/O card installed in an ad-
jacent slot.
1 6
2 7
Bank A
3 8
4 9
Bank B
5 10
Figure 2-11
Multiplexer input expansion example
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Card 1
7021
11 16 21 26
12 17 22 27
13 18 23 28
14 19 24 29
15 20 25 30
Dual 1x24 and 1x36 Multiplexer
Figure 2-12 shows a possible switching system using a ma-
trix and a multiplexer. The backplane jumpers for both the
matrix and multiplexer must be installed. This allows matrix
rows to be connected to multiplex banks. On the multiplex
banks, the bank-to-bank jumpers must be removed to main-
tain isolation between the matrix rows. See the instruction
manual for the Model 7022 for complete information on the
matrix.
7001/7002
Analog Backplane
1
2
3
4
5
Backplane
Jumpers
Installed
Multiplexer Configuration
Card 2
7021
6 11 16 21 26
7 12 17 22 27
8 13 18 23 28
9 14 19 24 29
10 15 20 25 30
2-7