Keithley 2001 Repair Manual

Troubleshooting
2-21
Table 2-12
R2_STB control registers
Register Bit Pin Control Description
U505 Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
4
5
6
7
14
13
12
11
DCF
SELFTEST
SELFTESTEN
SHORT
REL1
REL2
REL3
REL4
0 = U526 (divider) closed and U526 (ACA) open.
1 = Q518 off, U513 arms U503, and U522 (control pin 9) open.
1 = Arms U513 (pin 5) for SELFTEST.
0 = U526 closed (common to AC Buffer).
1 = Q504 on; closes relay K502 (ACV).
1 = Q519 on; closes relay K503 (SELFTEST).
1 = Opens U510 and turns on Q500 which closes relay K501 (pins
4 and 5).
1 = Q502 on; closes K500 (Q503 on).
U500 Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
4
5
6
7
14
13
12
11
750V
ACLOW
RANGE
/PEAK
/RSTPK
TRIG9
TRIGLEV
SEL
0 = U526 on (/500 AC divider).
0 = Q513 on and Q516 off, 1 = Q513 off and Q516 on.
1 = U515 closed and Q508 on (x10 rectiÞer).
0 = Q533 off; disables peak circuit.
0 = U510 (pin 9) closed and U510 (pin 16) open.
0 = Q520 off; increases DAC resolution (1/512).
0 = U515 closed and Q542 on.
0 = Hold DAC B, 1 = hold DAC A.
U530 Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
4
5
6
7
14
13
12
11
TRIG8
TRIG7
TRIG6
TRIG5
TRIG4
TRIG3
TRIG2
TRIG1
Bit DB0 of DAC U531 (LSB).
Bit DB1 of DAC U531.
Bit DB2 of DAC U531.
Bit DB3 of DAC U531.
Bit DB4 of DAC U531.
Bit DB5 of DAC U531.
Bit DB6 of DAC U531.
Bit DB7 of DAC U531 (MSB).
U501 Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
4
5
6
7
14
13
12
11
SEL1
SEL2
SEL3
FREQ
RMS
DAC
nc
nc
SEL1, SEL2 and SEL3 control lines
determine which MUX switch (U511)
is closed (see Table 2-13).
1 = Arms U508 and closes U522.
0 = U532 (pin 9) closed and U510 open.
0 = U532 (pin 1) closed; DAC V to AC Buffer.
x
x

Keithley 2001 Specifications

General

Brand	Keithley
Model	2001
Category	Multimeter
Language	English