Troubleshooting
2-24
Bit patterns
Test 200.2 — A/D noise
Type
Pass/Fail
Fault message
Signal conditioning noisy
Description
This test uses the same circuit setup as test 200.1. The A/D is triggered for 10 readings and a
minimum/maximum comparison is done for 50 counts or less. Failing this test indicates A/D
buffer noise or A/D converter circuit noise.
Drawing reference
Analog Board; 2002-140
A/D Converter; 2002-160
Components
A/D buffer or converter noise, power supply or reference supply noise.
Bit patterns
Bit pattern* Register
—U400—
01111011
—U811—
00001101
—U224—
00010111
—U432—
10000000
—U810—
00010111
—U206—
01110000
—U203—
10001110
—U411—
11111011
—U809—
01101111
—U207—
00001111
—U221—
11101001
—U406—
00000100
AD_STB
MUX_STB
R1_STB
R2_STB
*Bits associated with register IC terminals as follows:
QQQQQQQQ
87654321 87654321 87654321 87654321
IC pins: Q8=11, Q7=12, Q6=13, Q5=14, Q4=7, Q3=6, Q2=5, Q1=4.
Bit pattern* Register
—U400—
01111011
—U811—
00001101
—U224—
00010111
—U432—
10000000
—U810—
00010111
—U206—
01110000
—U203—
10001110
—U411—
11111011
—U809—
01101111
—U207—
00001111
—U221—
11101001
—U406—
00000100
AD_STB
MUX_STB
R1_STB
R2_STB
*Bits associated with register IC terminals as follows:
QQQQQQQQ
87654321 87654321 87654321 87654321
IC pins: Q8=11, Q7=12, Q6=13, Q5=14, Q4=7, Q3=6, Q2=5, Q1=4.
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