Keithley 2002 Repair Manual page 110

Bit patterns
Test 412.2 — Frequency, phase 2
Type
Fault message
Description
Drawing reference
Bit patterns
—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 is
configured to set up the U816 ASIC to read frequency.
Analog Board; 2002-100
A/D Converter; 2002-160
—U811—
00001010
—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—
10111000
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
2-97