This quick reference guide includes summary
information on front panel operation and IEEE-488
operation for the Model 182 Sensitive Digital Voltmeter .
For detailed Model 182 information, consult the Model
182 Instruction Manual.
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
2
SAFETY PRECAUTIONS
The following safety precautions should be observed
before using this product and any associated instrumentation. Although some instruments and accessories would normally be used with non-hazardous voltages, there are situations where hazardous conditions
may be present.
This product is intended for use by qualified personnel who recognize shock hazards and are familiar with
the safety precautions required to avoid possible injury. 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 protected from electric shock and contact with hazardous live circuits.
Maintenance personnel perform routine procedures on
the product to keep it operating, for example, setting
the line voltage or replacing consumable materials.
Maintenance procedures are described in the manual.
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,
and perform safe installations and repairs of products.
3
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 Installation Category II, as described in the International
Electrotechnical Commission (IEC) Standard IEC
60664. Most measurement, control, and data I/O signals are Installation Category I and must not be directly connected to mains voltage or to voltage sources
with high transient over-voltages. Installation Category
II connections require protection for high transient overvoltages often associated with local AC mains connections. 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 connector jacks or test fixtures. The American National
Standards Institute (ANSI) states that a shock hazard
exists when voltage levels greater than 30V RMS,
42.4V peak, or 60VDC are present. A good safety practice 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
that users are prevented access and/or insulated from
every connection point. In some cases, connections
must be exposed to potential human contact. Product
users in these circumstances must be trained to protect 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.
4
Do not connect switching cards directly to unlimited
power circuits. They are intended to be used with impedance limited sources. NEVER connect switching
cards directly to AC 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 receptacle. Inspect the connecting cables, test leads,
and jumpers for possible wear, cracks, or breaks before 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 applied to the circuit under test. AL W A YS remove power
from the entire test system and discharge any capacitors before: connecting or disconnecting cables or
jumpers, installing or removing switching cards, or
making internal changes, such as installing or removing 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 measurements with dry hands while standing on a dry, insulated surface capable of withstanding the voltage being measured.
The instrument and accessories must be used in accordance with its specifications and operating instructions or the safety of the equipment may be impaired.
5
Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and operating information, and as shown on
the instrument or test fixture panels, or switching card.
When fuses are used in a product, replace with same
type and rating for continued protection against fire
hazard.
Chassis connections must only be used as shield connections 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 operation 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 documentation.
The symbol on an instrument indicates that the user
should refer to the operating instructions located in
the manual.
The symbol on an instrument shows that it can source
or measure 1000 volts or more, including the combined effect of normal and common mode voltages.
Use standard safety precautions to avoid personal
contact with these voltages.
The WARNING heading in a manual explains dangers
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.
6
Instrumentation and accessories shall not be connected 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
the power transformer, test leads, 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 purchased from other suppliers as long as they are equivalent to the original component. (Note that selected parts
should be purchased only through Keithley Instruments
to maintain accuracy and functionality of the product.)
If you are unsure about the applicability of a replacement component, call a Keithley Instruments office for
information.
T o clean an instrument, use a 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. Products that consist of a circuit board with no case or chassis (e.g., data acquisition board for installation into a
computer) should never require cleaning if handled
according to instructions. If the board becomes contaminated and operation is affected, the board should
be returned to the factory for proper cleaning/servicing.
7
CONTROL SUMMARY
RANGE
Use UP and DOWN to manually select desired measurement range; 3mV, 30mV, 300mV, 3V, or 30V.
Present range is displayed on status line.
Press AUT O to turn auto-range on or off. Unit upranges
at overflow point (±3,029,999 counts) and downranges
at 9.33% of full range when AUTO is enabled.
Use FILTER to enable or disable both digital and analog 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, TRIGGER SOURCE, TRIGGER DELAY, AND TRIGGER
INTERVAL.
8
Use ▲ or ▼ to scroll through selections, ENTER to
select, or ESC to cancel selection.
TRIGGER MODE: select multiple (continuous with one trigger) or one-shot (one reading per trigger).
TRIGGER SOURCE: select external,
manual, disabled, or IEEE-488 X, GET or
talk triggers.
TRIGGER DELAY: program desired trigger delay (time between trigger and reading 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
size of 1-1024 selects linear buffer (storage stops when
size limitation is reached); store size of 0 selects circular buffer (buffer wraps around and overwrites old
data after 1024 readings are stored). Unit stores readings 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.
9
SELECTION
Use ▲ or ▼ to scroll through MENU, SETUP, and RECALL selections. Press ENTER to choose displayed
selection and move down one menu level (where applicable). Press ESC to cancel displayed selection and
move up one menu level (where applicable).
Use MENU to access operating modes summarized
below.
MENU MessageDescription
FILTERSet digital filter response,
analog filter on/off
INTEGRATIONSet A/D integration period
TIME(3msec, line cycle, or
100msec)
DISPLAYSet display resolution to
RESOLUTION3 1/2, 4 1/2, 5 1/2, or 6 1/2
digits
READING RELProgram reading relative value
OUTPUTSet analog output gain and
relative value
SETUPSave user setup, recall user or
factory default setup
SET IEEESelect IEEE-488 primary
ADDRESSaddress (0-30)
CALIBRATEDisplay test, calibrate Model
182, configure analog output
for normal or source
10
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
DescriptionDefault State
Range30V, auto-range off
Reading relativeOff, value =0V
Analog FilterOff
Digital FilterOn, medium response
BufferOff, size = 0000 (wrap around)
Analog OutputRelative off, value: 0V, gain: 1.0,
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.
C0, valueCalibrate measure positive full scale
C1, valueCalibrate measure negative full scale
C2Calibrate measure zero offset
C3, valueCalibrate divider full scale
C4Calibrate divider zero
C5Select positive full scale output
C6, valueCalibrate positive full scale output
C7Select zero output value
C8, valueCalibrate zero output with value
Filter Damping
D0Turn filter damping off (same as P2)
D1Turn filter damping on (same as P3)
Reading Source
F0Latest reading from A/D converter
F1One reading from buffer
F2All readings in buffer
F3Maximum value in buffer
F4Minimum value in buffer
16
Reading Format
G0Reading only
G1Reading with prefix
G2Reading with buffer location
G3Reading with buffer location and prefix
G4Reading with time stamp
G5Reading with time stamp and prefix
G6Reading with time stamp and location
G7Reading with time stamp, location, and prefix
Immediate Trigger and Self-test
H0Initiate manual trigger
H1Perform memory test
Buffer Configuration
I0Disable buffer
I1, valueBuffer on, linear length=value
I2Buffer on, circular length=1024
Analog Output Relative
J0Disable analog output relative
J1Enable analog output relative using next
J2, valueEnable analog output relative using value
J3Enable analog output relative, use present
reading
value
17
EOI, Bus Hold-off on X
K0Enable EOI, enable bus hold-off on X
K1Disable EOI, enable bus hold-off on X
K2Enable EOI, disable bus hold-off on X
K3Disable EOI, disable bus hold-off on X
Save and Recall Setup
L0Save current setup as power-on
L1Recall factory default setup
L2Recall power-on setup
SRQ Mask
M0Disable SRQ
M1Reading done
M2Buffer half full
M4Buffer full
M8Reading overflow
M16Ready for command
M32Error
M128Ready for trigger
Enable/Disable Analog and Digital Filters
N0Filters off
N1Filters on
18
Analog Filter Configuration
O0Configure analog filter off
O1Configure analog filter on
Digital Filter Configuration
P0Configure digital filter off
P1Configure fast response
P2Configure medium response
P3Configure slow response
Trigger Interval
Qvalue Interval=value in msec (10-999 999msec)
Range
R0Enable auto-range
R13mV range
R230mV range
R3300mV range
R43V range
R530V range
R6No function
R7No function
R8Disable auto-range
19
Integration Period
S0Line cycle integration period
S13msec integration period
S2100msec integration period
Trigger Mode and Source
T0Multiple on talk
T1One-shot on talk
T2Multiple on GET
T3One-shot on GET
T4Multiple on X
T5One-shot on X
T6Multiple on external
T7One-shot on external
T8Multiple on manual (MANUAL key or H0X)
T9One-shot on manual (MANUAL key or H0X)
T10Disable all triggers
20
Alternate Output
U0Send machine status
U1Send error conditions
U2Send firmware revision
U3Send buffer length
U4Send buffer average
U5Send buffer standard deviation
U6Send reading relative value
U7Send analog output relative value
U8Send analog output gain value
U9Send trigger interval
U10Send trigger delay
U11Send calibration constants
U12Send calibration lock status
U13Send Model 181-like machine status
U14Send ASCII text string
Analog Output Mode, Gain, and Output Value
V0, gainNormal mode, gain (.001-999 999.999)
V1, valueSource mode, output=value (-3.3 to +3.3)
Z0Disable reading relative
Z1Enable reading relative using next reading
Z2, valueEnable reading relative using value
Z3Enable reading relative, use present value
22
DATA FORMATS
Prefix
(G1, G3, G5, G7)
Mantissa Exponent
Buffer
Location
(G2, G3, G6, G7)
Time
Stamp
(G4, G5, G6, G7)
NDCV+1.820000E+00, 0000, 000000.000<term+EOI>
Field Separators
DCV = Normal Reading
MAX = Maximum buffer reading (F3)
MIN = Minimum buffer reading (F4)
N = Normal
O = Overflow
R = Relative enabled
Notes : 1. Buffer location and time stamp
fields show all 0s for all
readings (F0).
2. Time stamp is elapsed time
from first trigger after buffer
is enabled.
Figure 2. Reading Format
23
PrefixMantissa Exponent
Buffer
Location
Time
Stamp
NMAX+1.820000E+00, 0001, 000000.00<term+EOI>
Notes : 1. G7 reading format shown. Presence of
prefix, buffer location, and time stamp
depends on selected data format.
2. Buffer location and time stamp values
are at location of maximum buffer reading.
Figure 3. Maximum Buffer Value Format
PrefixMantissa Exponent
Buffer
Location
Time
Stamp
NMIN+1.820000E+00, 0001, 000000.00<term+EOI>
Notes : 1. G7 reading format shown. Presence of
prefix, buffer location, and time stamp
depends on selected data format.
2. Buffer location and time stamp values
are at location of minimum buffer reading.
0 = EOI, hold-off on
1 = EOI off, hold-off on
2 = EOI on, hold-off off
3 = EOI off, hold-off off
S (Integration)
0 = Line cycle
1 = 3msec
2 = 100msec
F (Data Source)
0 = A/D
1 = Single Buffer
2 = Full Buffer
3 = Maximum Buffer
4 = Minimum Buffer
Note: Default values shown
M (SRQ)
000 = Disabled
001 = Reading Done
002 = Buffer half full
004 = Buffer full
008 = Reading overflow
016 = Ready for command
032 = Error
128 = Ready for trigger
T (Trigger)
00 = Multiple on talk
01 = One-shot on talk
02 = Multiple on GET
03 = One shot on GET
04 = Multiple on X
05 = One-shot on X
06 = Multiple on external
07 = One-shot on external
08 = Multiple on manual
09 = One-shot on manual
10 = All triggers disabled
Figure 6. U0 Word Format (Machine Status)
26
G (Data Format)
0 = Reading only
1 = Prefix
2 = Location
3 = Location prefix
4 = Time stamp
5 = Time stamp, prefix
6 = Time stamp, location
7 = Prefix, location, and time
stamp
N (Filters)
0 = Off
1 = On
V (Output Configure)
0 = Normal
1 = Source
I (Buffer)
0 = Disabled
1 = Linear
2 = Circular
P (Digital Filter)
0 = Disabled
1 = Fast
2 = Medium
3 = Slow
,
O (Analog Filter)
0 = Off
1 = On
Y (Terminator)
0 = <CR> <LF>
1 = <LF> <CR>
2 = <CR>
3 = <LF>
J (Output Relative)
0 = Disabled
1 = Enabled, use next
reading
2 = Enabled using value
3 = Enabled using present value
0 = Disabled
1 = Enabled using reading
2 = Enabled using value
3 = Enabled using prior
value
K (EOI and Hold-off)
0 = EOI hold-off enabled
1 = EOI disabled, hold-off
enabled
2 = EOI enabled, hold-off
disabled
3 = Both EOI and hold-off off
disabled
Y (Terminator)
: <CR LF> or <LF>
= <LF CR> or CR
5 1 0 1 0 0 6 0 : <Term + EOI>
P (Digital Filter)
0 = Disabled
1 = Fast
2 = Medium
3 = Slow
Figure 19. U13 Word Format (Model 181-Like
D (Damping)
0 = Off
1 = On
M (SRQ)
0 = Disabled
1 = Enabled
Machine Status)
T (Trigger)
0 = Multiple on talk
1 = One-shot on talk
2 = Multiple on GET
3 = One-shot on GET
4 = Multiple on X
5 = One-shot on X
6 = Multiple on
external
7 = One-shot on
external
8 = Multiple on manual
9 = One-shot on manual
A = All triggers
disabled
34
Message
Identifier
String
Stored in EPROM
M S G <string> <term+EOI>
Figure 20. U14 Word Format (ASCII Message
String)
‘
Single Quote
Delimiters
‘
35
36
Specifications are subject to change without notice.
All Keithley trademarks and trade names are the property of
Keithley Instruments, Inc. All other trademarks and trade names
are the property of their respective companies.