Keithley 182 User manual

Model 182 Sensitive Digital Voltmeter
Quick Reference Guide
A GREATER MEASURE OF CONFIDENCE

1
INTRODUCTION
This quick reference guide includes summary
information on front panel operation and IEEE-488
operationfortheModel182SensitiveDigitalVoltmeter.
Fordetailed Model 182 information,consult the Model
182 Instruction Manual.
©1990, Keithley Instruments, Inc.
All Rights Reserved
Cleveland, Ohio, U.S.A.
Document Number: 182-903-01 Rev. B

2
TABLE OF CONTENTS
SAFETY PRECAUTIONS ....................................... 3
CONTROL SUMMARY ........................................... 8
TEST CONNECTIONS ......................................... 14
DEVICE DEPENDENT COMMANDS ...................15
DATA FORMATS ................................................... 23
SRQ MASK AND SERIAL POLL BYTE................. 25
ALTERNATE OUTPUT WORD FORMATS ........... 26

3
SAFETY PRECAUTIONS
The following safety precautions should be observed
before using this product and any associated instru-
mentation. Although some instruments and accesso-
ries would normally be used with non-hazardous volt-
ages,thereare situations where hazardous conditions
may be present.
This product is intended for use by qualified person-
nelwho recognize shock hazards andare familiar with
the safety precautions required to avoid possible in-
jury. Read the operating information carefully before
using the product.
The types of product users are:
Responsible body is the individual or group respon-
sible for the use and maintenance of equipment, for
ensuring that the equipment is operated within its
specifications and operating limits, and for ensuring
that operators are adequately trained.
Operators use the product for its intended function.
They must be trained in electrical safety procedures
and proper use of the instrument. They must be pro-
tected from electric shock and contact with hazard-
ous live circuits.
Maintenancepersonnelperformroutineprocedureson
the product to keep it operating, for example, setting
the line voltage or replacing consumable materials.
Maintenanceproceduresare described in themanual.
The procedures explicitly state if the operator may
perform them. Otherwise, they should be performed
only by service personnel.
Service personnel are trained to work on live circuits,
andperform safe installations andrepairs of products.

4
Only properly trained service personnel may perform
installation and service procedures.
Keithley products are designed for use with electrical
signals that are rated Installation Category I and In-
stallationCategory II, as describedin the International
Electrotechnical Commission (IEC) Standard IEC
60664. Most measurement, control, and data I/O sig-
nals are Installation Category I and must not be di-
rectlyconnectedtomainsvoltageortovoltagesources
withhightransientover-voltages. Installation Category
IIconnectionsrequireprotectionforhightransientover-
voltages often associated with local AC mains con-
nections. The user should assume all measurement,
control, and data I/O connections are for connection
to Category I sources unless otherwise marked or
described in the Manual.
Exercise extreme caution when a shock hazard is
present. Lethal voltage may be present on cable con-
nector jacks or test fixtures. The American National
Standards Institute (ANSI) states that a shock hazard
exists when voltage levels greater than 30V RMS,
42.4Vpeak,or60VDCarepresent.Agoodsafetyprac-
tice is to expect that hazardous voltage is present in
any unknown circuit before measuring.
Users of this product must be protected from electric
shock at all times. The responsible body must ensure
thatusers are prevented accessand/orinsulated from
every connection point. In some cases, connections
must be exposed to potential human contact. Product
users in these circumstances must be trained to pro-
tect themselves from the risk of electric shock. If the
circuit is capable of operating at or above 1000 volts,
no conductive part of the circuit may be exposed.

5
Do not connect switching cards directly to unlimited
power circuits. They are intended to be used with im-
pedance limited sources. NEVER connect switching
cards directly toAC mains. When connecting sources
to switching cards, install protective devices to limit
fault current and voltage to the card.
Before operating an instrument, make sure the line
cord is connected to a properly grounded power re-
ceptacle. Inspect the connecting cables, test leads,
and jumpers for possible wear, cracks, or breaks be-
fore each use.
When installing equipment where access to the main
power cord is restricted, such as rack mounting, a
separate main input power disconnect device must
be provided, in close proximity to the equipment and
within easy reach of the operator.
For maximum safety, do not touch the product, test
cables, or any other instruments while power is ap-
plied to the circuit under test.ALWAYS remove power
fromthe entire testsystem and discharge anycapaci-
tors before: connecting or disconnecting cables or
jumpers, installing or removing switching cards, or
making internal changes, such as installing or remov-
ing jumpers.
Do not touch any object that could provide a current
path to the common side of the circuit under test or
power line (earth) ground. Always make measure-
ments with dry hands while standing on a dry, insu-
lated surface capable of withstanding the voltage be-
ing measured.
The instrument and accessories must be used in ac-
cordancewith its specifications andoperating instruc-
tions or the safety of the equipment may be impaired.

6
Do not exceed the maximum signal levels of the in-
struments and accessories, as defined in the specifi-
cations and operating information, and as shown on
theinstrument or test fixturepanels, or switching card.
When fuses are used in a product, replace with same
type and rating for continued protection against fire
hazard.
Chassisconnections must only be usedas shield con-
nections for measuring circuits, NOT as safety earth
ground connections.
If you are using a test fixture, keep the lid closed while
power is applied to the device under test. Safe opera-
tion requires the use of a lid interlock.
If a screw is present, connect it to safety earth ground
using the wire recommended in the user documenta-
tion.
The symbol on an instrument indicates that the user
should refer to the operating instructions located in
the manual.
Thesymbol on aninstrument shows that it can source
or measure 1000 volts or more, including the com-
bined effect of normal and common mode voltages.
Use standard safety precautions to avoid personal
contact with these voltages.
TheWARNINGheading in a manualexplainsdangers
that might result in personal injury or death. Always
read the associated information very carefully before
performing the indicated procedure.
The CAUTION heading in a manual explains hazards
that could damage the instrument. Such damage may
invalidate the warranty.

7
Instrumentation and accessories shall not be con-
nected to humans.
Before performing any maintenance, disconnect the
line cord and all test cables.
To maintain protection from electric shock and fire,
replacement components in mains circuits, including
thepowertransformer,testleads, and input jacks, must
be purchased from Keithley Instruments. Standard
fuses, with applicable national safety approvals, may
be used if the rating and type are the same. Other
components that are not safety related may be pur-
chasedfromother suppliers as long as theyareequiva-
lenttothe original component. (Note that selectedparts
shouldbepurchased only through Keithley Instruments
to maintain accuracy and functionality of the product.)
If you are unsure about the applicability of a replace-
mentcomponent, call aKeithley Instruments officefor
information.
Tocleananinstrument,usea damp cloth or mild, water
based cleaner. Clean the exterior of the instrument
only. Do not apply cleaner directly to the instrument or
allow liquids to enter or spill on the instrument. Prod-
uctsthatconsistofacircuitboardwithnocase or chas-
sis (e.g., data acquisition board for installation into a
computer) should never require cleaning if handled
according to instructions. If the board becomes con-
taminated and operation is affected, the board should
be returned to the factory for proper cleaning/servicing.

8
CONTROL SUMMARY
RANGE
Use UP and DOWN to manually select desired mea-
surement range; 3mV, 30mV, 300mV, 3V, or 30V.
Present range is displayed on status line.
PressAUTOtoturnauto-rangeonoroff.Unitupranges
atoverflowpoint (±3,029,999counts)anddownranges
at 9.33% of full range when AUTO is enabled.
Use FILTER to enable or disable both digital and ana-
log filters simultaneously (actual filter configuration or
response depends on MENU FILTER selections).
REL
Press REL READING to store current reading as
baseline. Subsequent readings will be the difference
between the applied signal and the stored baseline.
Press REL OUTPUT to store current analog output
value as analog output baseline. Analog output value
will be the difference between the normal, non-relative
output value and the stored analog output baseline.
TRIG
Press SETUP to program TRIGGER MODE, TRIG-
GER SOURCE, TRIGGER DELAY, AND TRIGGER
INTERVAL.

9
Use ▲or ▼to scroll through selections, ENTER to
select, or ESC to cancel selection.
TRIGGERMODE:selectmultiple(continu-
ouswithone trigger) or one-shot(oneread-
ing per trigger).
TRIGGER SOURCE: select external,
manual, disabled, or IEEE-488 X, GET or
talk triggers.
TRIGGER DELAY: program desired trig-
ger delay (time between trigger and read-
ing in one-shot trigger mode): 0sec-
999.999sec.
TRIGGER INTERVAL: program desired
trigger interval (time between individual
readings in multiple trigger mode): 0.01
sec-999.999sec.
BUFFER
Use STORE to start/stop buffer data storage. Store
sizeof1-1024selects linear buffer(storagestopswhen
size limitation is reached); store size of 0 selects cir-
cular buffer (buffer wraps around and overwrites old
dataafter 1024 readings arestored). Unit stores read-
ings at programmed trigger interval in multiple trigger
mode or one reading per trigger in one-shot trigger
mode.
Press RECALL to access stored buffer readings and
buffer statistics. Readings include buffer location and
time stamp. Statistics include number of samples,
buffer average, maximum, minimum, and standard
deviation.

10
SELECTION
Use ▲or ▼to scroll through MENU, SETUP, and RE-
CALL selections. Press ENTER to choose displayed
selection and move down one menu level (where ap-
plicable).PressESC to cancel displayed selectionand
move up one menu level (where applicable).
Use MENU to access operating modes summarized
below.
MENU Message Description
FILTER Set digital filter response,
analog filter on/off
INTEGRATION Set A/D integration period
TIME (3msec, line cycle, or
100msec)
DISPLAY Set display resolution to
RESOLUTION 3 1/2, 4 1/2, 5 1/2, or 6 1/2
digits
READING REL Program reading relative value
OUTPUT Set analog output gain and
relative value
SETUP Save user setup, recall user or
factory default setup
SET IEEE Select IEEE-488 primary
ADDRESS address (0-30)
CALIBRATE Display test, calibrate Model
182, configure analog output
for normal or source

11
Press LOCAL to cancel remote (REM on) when the
instrument is used over the IEEE-488 bus. LOCAL
will be locked out when the bus LLO command is in
effect.
FACTORY DEFAULT CONDITIONS
Description Default State
Range 30V, auto-range off
Reading relative Off, value =0V
Analog Filter Off
Digital Filter On, medium response
Buffer Off, size = 0000 (wrap around)
Analog Output Relative off, value: 0V, gain: 1.0,
normal output, source value
= 0V
Primary Address 7
Integration Period Line cycle (16.67msec @ 60Hz,
20msec @ 50Hz)
Display Resolution 6 1/2 digits
Trigger Mode Multiple
Trigger Source External (MANUAL key also
operative)
Trigger Interval 0.25sec
Trigger Delay 0sec
Calibration Lock On (calibration locked)
NOTE: All listed operating states except buffer status, primary address,
and calibration lock status can be saved as user configuration using
MENU save user setup selection. Primary address can be saved using
MENU SET IEEE ADDRESS selection.

12
ERROR MESSAGES
U1 Bit Display Message Description Type
Number*
0** INVALID COMMAND Invalid Device-Dependent Momentary
Command
1** INVALID OPTION Invalid Device-Dependent Momentary
Command Option
2** INVALID FORMAT Invalid Device-Dependent Momentary
Command Format
3** NOT IN REMOTE Unit not in remote when Momentary
programmed
4 TRIGGER OVERRUN Unit triggered while processing Momentary
reading (one-shot only)
5 OVERFLOW Input signal too large Momentary
for range
6 NVRAM ERROR NVRAM error found during Latching
self-test
7 RAM ERROR RAM error found during Latching
self-test
8 UNCALIBRATED Unit not calibrated Latching
Press a key to continue

13
U1 Bit Display Message Description Type
Number*
9 CAL RUNNING Invalid command or operation Momentary
when calibration unlocked
10 CAL LOCKED Calibration attempted with Momentary
calibration locked
11 CAL ERROR Improper calibration value Latching
Press a key to continue for applied signal
12 Reserved
13 Reserved
14
FRONT PANEL FAILURE
Front panel microcontroller Latching
communications failure
15 A/D COMM FAILURE A/D microcontroller Latching
communications failure
16 TRIGGER NOT READY Unit not ready for trigger Momentary
*
Number corresponds to bit position in U1 error word.
** IEEE-488 bus-only errors. INVALID FORMAT and INVALID OPTION commands display error type on
lower line.

14
TEST CONNECTIONS
KEITHLEY
182 SENSITIVE DIGITALVOLTMETER
182.3165 mV
Range 300mV
TRG
SRC
REM
TALK
LSTN
POWER RANGE REL TRIG BUFFER SELECTION INPUT
UP AUTO
DOWN FILTER
01 2 3 4
56 7 8 9
.
READING
OUTPUT
SETUP
MANUAL
STORE
RECALL
MENU
ENTER
LOCAL
ESC
CAL
LO 350V
MAX INPUT
30V MAX
Note: Use only clean copper-to-copper
connections to minimize thermals
Low thermal cable
(Model 1506 or Equivalent)
Red
Black
Voltage being
measured
Caution
Maximum Input: 35V continuous
120V for 10 seconds
WARNING: Maximum common-mode
voltage: 350V peak
Figure 1. Typical Test Connections

15
DEVICE DEPENDENT
COMMANDS
NOTE: Corresponding lower-case command letters
may be used in place of upper-case command letters.
Display ASCII String
A0 Restore display to normal
A1, string Display string
A2, string Display string and store in EEROM
A3 Display string stored in EEROM
Display Resolution
B0 5 1/2 digit resolution
B1 6 1/2 digit resolution
B2 3 1/2 digit resolution
B3 4 1/2 digit resolution
NOTE: String must be surrounded by single quotes.

16
Measure and Analog Output Source Calibration
C0, value Calibrate measure positive full scale
C1, value Calibrate measure negative full scale
C2 Calibrate measure zero offset
C3, value Calibrate divider full scale
C4 Calibrate divider zero
C5 Select positive full scale output
C6, value Calibrate positive full scale output
C7 Select zero output value
C8, value Calibrate zero output with value
Filter Damping
D0 Turn filter damping off (same as P2)
D1 Turn filter damping on (same as P3)
Reading Source
F0 Latest reading fromA/D converter
F1 One reading from buffer
F2 All readings in buffer
F3 Maximum value in buffer
F4 Minimum value in buffer

17
Reading Format
G0 Reading only
G1 Reading with prefix
G2 Reading with buffer location
G3 Reading with buffer location and prefix
G4 Reading with time stamp
G5 Reading with time stamp and prefix
G6 Reading with time stamp and location
G7 Reading with time stamp, location, and prefix
Immediate Trigger and Self-test
H0 Initiate manual trigger
H1 Perform memory test
Buffer Configuration
I0 Disable buffer
I1, value Buffer on, linear length=value
I2 Buffer on, circular length=1024
Analog Output Relative
J0 Disable analog output relative
J1 Enable analog output relative using next
reading
J2, value Enable analog output relative using value
J3 Enable analog output relative, use present
value

18
EOI, Bus Hold-off on X
K0 Enable EOI, enable bus hold-off on X
K1 Disable EOI, enable bus hold-off on X
K2 Enable EOI, disable bus hold-off on X
K3 Disable EOI, disable bus hold-off on X
Save and Recall Setup
L0 Save current setup as power-on
L1 Recall factory default setup
L2 Recall power-on setup
SRQ Mask
M0 Disable SRQ
M1 Reading done
M2 Buffer half full
M4 Buffer full
M8 Reading overflow
M16 Ready for command
M32 Error
M128 Ready for trigger
Enable/Disable Analog and Digital Filters
N0 Filters off
N1 Filters on

19
Analog Filter Configuration
O0 Configure analog filter off
O1 Configure analog filter on
Digital Filter Configuration
P0 Configure digital filter off
P1 Configure fast response
P2 Configure medium response
P3 Configure slow response
Trigger Interval
Qvalue Interval=value in msec (10-999 999msec)
Range
R0 Enable auto-range
R1 3mV range
R2 30mV range
R3 300mV range
R4 3V range
R5 30V range
R6 No function
R7 No function
R8 Disable auto-range