Keithley 2002 Repair Manual page 114

Test 412.9 — Frequency, phase 9
Type
Fault message
Description
Drawing reference
Bit patterns
Test 412.10 — Frequency, phase 10
Type
Fault message
Description
Drawing reference
Bit patterns
Pass/Fail
Frequency counter circuit
This test uses the same setup as test 412.1 except that shift register U811 on the A/D board sets
up the U816 ASIC to finish reading frequency and transfer the internal counts to the digital
board.
Analog Board; 2002-100
A/D Converter; 2002-160
—U811—
00000000
—U224—
00010111
—U400— —U432—
01001100 11001010
*Bits associated with register IC terminals as follows:
Q Q Q Q
87654321 87654321
IC pins: Q8=11, Q7=12, Q6=13, Q5=14, Q4=7, Q3=6, Q2=5, Q1=4.
Circuit Exercise
None
This test uses the same setup as test 412.1 except that shift register U811 on the A/D board sets
up the U816 ASIC to finish reading frequency and transfer the internal counts to the digital
board. The counts are compared to the value obtained when the circuit was switched.
Analog Board; 2002-100
A/D Converter; 2002-160
—U811—
0000100
—U224—
00010111
—U400— —U432—
01001100 11001010
*Bits associated with register IC terminals as follows:
Q Q Q Q
87654321 87654321
IC pins: Q8=11, Q7=12, Q6=13, Q5=14, Q4=7, Q3=6, Q2=5, Q1=4.
Bit pattern*
—U810—
00000000
—U206—
01110000
—U203—
10001110
—U411—
10111000
Q Q Q Q
87654321 87654321
Bit pattern*
—U810—
00000000
—U206—
01110000
—U203—
10001110
—U411—
10111100
Q Q Q Q
87654321 87654321
Troubleshooting
Register
—U809— AD_STB
00000000
—U207— MUX_STB
11001111
—U221— R1_STB
11101001
—U406— R2_STB
11101100
Register
—U809— AD_STB
00000000
—U207— MUX_STB
11001111
—U221— R1_STB
11101001
—U406— R2_STB
11101100
2-101