Keithley 2002 Repair Manual

Troubleshooting
2-95
Bit patterns
Test 411.2 — Filter; variable gain amplifier
Type
Pass/Fail
Fault message Filter
Description REFHI is tied to pin 1 of U420 and buffered to form BUFF. BUFF through R493, K403, K401,
input protection, and Q421 is tied to the input buffer Q418 and U423. The buffered BUFF signal
(AMP IN) is tied to the FWR, and, being positive, follows the non-inverting, X1 path R452,
Q412, Q411, U417, R453, U410, Q404, and U419 to the filter through U412. Output of the filter
R435, R446, R447, C433, C434, C432, and U426 is tied to U414 pin 5, and the output of U414
is tied to the A/D buffer through buffer U403, R434, R462, and U222. The A/D buffer is config-
ured for X1 gain.
Drawing reference Analog Board; 2002-100
Components U410, U412, U417, U419, U420, U423, U426, and associated components.
Bit patterns
Bit pattern* Register
—U400—
01011001
—U811—
00001101
—U224—
00010111
—U432—
11000000
—U810—
00000011
—U206—
01110000
—U203—
10001110
—U411—
10111001
—U809—
11100111
—U207—
11001111
—U221—
11101001
—U406—
10101110
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—
01011001
—U811—
00001101
—U224—
00010111
—U432—
10000000
—U810—
00000011
—U206—
01110000
—U203—
10001110
—U411—
11111001
—U809—
11100111
—U207—
11001111
—U221—
11101001
—U406—
10101110
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.

Keithley 2002 Specifications

General

Resolution	8.5 digits
DC Voltage Accuracy	±0.0006%
Maximum DC Voltage	1000 V
Maximum AC Voltage	750 V
Maximum DC Current	3 A
Maximum AC Current	3 A
Connectivity	GPIB, RS-232
DC Voltage Range	100 mV to 1000 V
AC Voltage Range	100 mV to 750 V
Resistance Range	10 Ω to 1 GΩ
Model	2002
Category	Multimeter
Interface	GPIB, RS-232
AC Current Accuracy	±0.1%
Frequency Range	0.1Hz to 300kHz
Display	VFD
Type	Digital
Power Supply	100-240V AC, 50/60Hz
Current Range (DC)	100 μA to 3 A
Current Accuracy (DC)	±0.01%
Current Range (AC)	100 μA to 3 A
Current Accuracy (AC)	±0.1%
DC Current Range	100 μA to 3 A
AC Current Range	100 μA to 3 A