Keithley 2001 Repair Manual

Troubleshooting
2-20
Table 2-11
R1_STB control registers
Register Bit Pin Control Description
U307 Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
4
5
6
7
14
13
12
11
OHM FA
OHM FB
4W OHM
/OHM CAL
/4 DIGIT
OHM FD
/LOV/OHM, BSCOM
/2M
U332 ohms range select (LSB).
U332 ohms range select (MSB).
0 = U323 closed, 1 = U323 open.
0 = OHM CAL to A/D Buffer (via U320).
0 = BSCOM or common (via U317) to A/D Buffer
(U319 closed).
1 = U332 Inhibit (INH); all channels off.
1 = Q333 off, 0 = Q333 on to connect signal to BSCOM.
0 = Q329 on (10MΩ range).
U305 Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
4
5
6
7
14
13
12
11
4 DIGIT
OHM
VLO, /VLO
HI OHM, /HI OHM
/HIV
/DIVIDER, BSCOM
OHM SELECT, /4W
OHM, BSCOM
/200M
0 = Common to A/D Buffer (via U317).
1 = K300 closed (OHMS relay).
1 = U336 and U337 turns on Q337-Q340.
1 = Q320 and Q312 off, Q324 on.
1 = Q328 off; opens divider common.
1 = Q525 off, 0 = Q525 on to connect divider signal to
BSCOM.
0 = U323 closed and Q331 on to connect signal to
BSCOM.
0 = U323 closed (/16 gain for 4.4nA ohms source).
U302 Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
4
5
6
7
14
13
12
11
/ACA
/ACAL
/200µA
/2mA
/20mA
/200mA
/2A
nc
0 = U320 (ACA) and U522 (ACBS) closed.
0 = U323 closed.
0 = U317 closed (1kΩ shunt).
0 = U317 closed (100Ω shunt).
0 = Q311 on (10Ω shunt).
0 = Q309 and Q307 on (1Ω shunt).
0 = Q310 and Q305 on (0.1Ω shunt).
x

Keithley 2001 Specifications

General

Model	2001
Category	Multimeter
Manufacturer	Keithley
Type	Digital Multimeter
Digits of Resolution	7.5
DC Voltage Range	100 mV to 1000 V
AC Voltage Range	100 mV to 750 V
Frequency Range	3 Hz to 500 kHz
Connectivity	GPIB, RS-232
Display	VFD
Resistance Accuracy	0.008% + 2.0 mΩ
Frequency Accuracy	±0.01%
DC Current Range	10 μA to 3 A
AC Current Range	10 μA to 3 A
Power Supply	100 V to 240 V AC, 45 Hz to 66 Hz