Keithley 7022, Instruction Manual

Page: 71 / 107

Service Information
6-3
Channel resistance tests
Referring to Figure 6-1, perform the following steps to verify
that each contact of every relay is closing properly and that
the resistance is within specification.
1. Turn off the Model 7001/7002 if it is on.
2. As shown in Figure 6-1, connect all terminals of matrix
columns 1-6 together to form one common terminal.
3. Set the Model 2000 to the 100
Ω
range and connect four
test leads to the INPUT and SENSE
Ω
4 WIRE input.
4. Short the four test leads together and zero the Model
2000. Leave zero enabled for the entire test.
5. Connect INPUT HI and SENSE
Ω
4 WIRE HI of the
Model 2000 to the common terminal. It is recommended
that the physical connections be made at columns 1 and
6 as shown in the illustration.
6. Connect INPUT LO and SENSE
Ω
4 WIRE LO to the
high (H) terminal of row A.
7. Install the Model 7022 in slot 1 (CARD 1) of the Model
7001/7002.
8. Turn on the Model 7001/7002 and program it to close
channel 1!1 (row A, column 1). Verify that the resistance
of this channel is <1.25
Ω
.
9. Open channel 1!1 and close 1!6. Verify that the resis-
tance of this channel is <1.25
Ω
.
10. Open channel 1!6 and close 1!11. Verify that the resis-
tance of this channel is <1.25
Ω
.
11. Repeat the basic procedure of opening and closing chan-
nels to check the resistance of row A high (H) terminal
paths for columns 4 through 6 (channels 1!16, 1!21, and
1!26).
12. Turn off the Model 7001/7002 and connect the INPUT
LO and SENSE
Ω
4 WIRE LO test leads of the Model
2000 DMM to the low (L) terminal of row A.
13. Repeat steps 8 through 11 to check the low (L) channel
paths of row A.
14. Turn off the Model 7001/7002 and repeat the basic pro-
cedure in steps 7 through 13 for rows B, C, D, and E.
Figure 6-1
Path resistance testing
HI
LO
POWER
A
B
C
1 3 4 5 6 2
Model 7022
Model 2000
Jumpers
Sense
Ω
4 Wire HI
Input HI
Input LO
Sense
Ω
4
Wire LO
(Measure 4-Wire Ohms)
Setup shown is configured
to test the high (H) terminal
of row A through crosspoints
1!1, 1!6, 1!11, 1!16,
1!21, and 1!26.
Rows
Columns
D
E
Note:
H
L
H
L
H
L
H
L
H
L
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