Tektronix Series 2281 Precision DC Supply,Battery Simulator Reference manual

Model 2281S-20-6 Precision DC
Power Supply and Battery Simulator

Reference Manual

077114601 / March 2019

tek.com/keithley

*P077114601*

077114601

DC Power Supply and Battery Simulator

Model 2281S-20-6

Reference Manual

© 2019, Keithley Instruments, LLC

Cleveland, Ohio, U.S.A.

All rights reserved.

Any unauthorized reproduction, photocopy, or use of the information herein, in whole or in part,

without the prior written approval of Keithley Instruments, LLC, is strictly prohibited.

These are the original instructions in English.

All Keithley Instruments product names are trademarks or registered trademarks of Keithley

Instruments, LLC. Other brand names are trademarks or registered trademarks of their respective

holders.

Microsoft, Visual C++, Excel, and Windows are either registered trademarks or trademarks of

Microsoft Corporation in the United States and/or other countries.

Document number: 077114601 / March 2019

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 nonhazardous voltages, there are situations where hazardous
conditions may be present.

This product is intended for use by personnel who recognize shock hazards and are familiar with the safety precautions required
to avoid possible injury. Read and follow all installation, operation, and maintenance information carefully before using the
product. Refer to the user documentation for complete product specifications.

If the product is used in a manner not specified, the protection provided by the product warranty may be impaired.
The types of product users are:

Responsible body is the individual or group responsible 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 properly, for example, setting the line
voltage or replacing consumable materials. Maintenance procedures are described in the user documentation. 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, perform safe installations, and repair products. Only properly trained
service personnel may perform installation and service procedures.

Keithley products are designed for use with electrical signals that are measurement, control, and data I/O connections, with low
transient overvoltages, and must not be directly connected to mains voltage or to voltage sources with high transient
overvoltages. Measurement Category II (as referenced in IEC 60664) connections require protection for high transient
overvoltages often associated with local AC mains connections. Certain Keithley measuring instruments may be connected to
mains. These instruments will be marked as category II or higher.

Unless explicitly allowed in the specifications, operating manual, and instrument labels, do not connect any instrument to mains.
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
30 V RMS, 42.4 V peak, or 60 VDC are present. A good safety practice is to expect that hazardous voltage is present in any
unknown circuit before measuring.

Operators of this product must be protected from electric shock at all times. The responsible body must ensure that operators
are prevented access and/or insulated from every connection point. In some cases, connections must be exposed to potential
human contact. Product operators 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 V, no conductive part of the circuit may be exposed.

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, ensure that 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. ALWAYS 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.

For safety, instruments and accessories must be used in accordance with the operating instructions. If the instruments or
accessories are used in a manner not specified in the operating instructions, the protection provided by the equipment may be
impaired.

Do not exceed the maximum signal levels of the instruments and accessories. Maximum signal levels are defined in the
specifications and operating information and shown on the instrument panels, test fixture panels, and switching cards.

When fuses are used in a product, replace with the same type and rating for continued protection against fire hazard.
Chassis connections must only be used as shield connections for measuring circuits, NOT as protective earth (safety 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 protective earth (safety ground) using the wire recommended in the user documentation.

The symbol on an instrument means caution, risk of hazard. The user must refer to the operating instructions located in the
user documentation in all cases where the symbol is marked on the instrument.

The symbol on an instrument means warning, risk of electric shock. Use standard safety precautions to avoid personal
contact with these voltages.

The symbol on an instrument shows that the surface may be hot. Avoid personal contact to prevent burns.

The symbol indicates a connection terminal to the equipment frame.

If this symbol is on a product, it indicates that mercury is present in the display lamp. Please note that the lamp must be
properly disposed of according to federal, state, and local laws.

The WARNING heading in the user documentation explains hazards that might result in personal injury or death. Always read
the associated information very carefully before performing the indicated procedure.

The CAUTION heading in the user documentation explains hazards that could damage the instrument. Such damage may
invalidate the warranty.

The CAUTION heading with the symbol in the user documentation explains hazards that could result in moderate or minor
injury or damage the instrument. Always read the associated information very carefully before performing the indicated
procedure. Damage to the instrument may invalidate the warranty.

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. Standard fuses with applicable national safety
approvals may be used if the rating and type are the same. The detachable mains power cord provided with the instrument may
only be replaced with a similarly rated power cord. 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 to maintain accuracy and functionality of the product). If you are unsure about the applicability of a replacement
component, call a Keithley office for information.

Unless otherwise noted in product-specific literature, Keithley instruments are designed to operate indoors only, in the following
environment: Altitude at or below 2,000 m (6,562 ft); temperature 0 °C to 50 °C (32 °F to 122 °F); and pollution degree 1 or 2.

To clean an instrument, use a cloth dampened with deionized water 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., a 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.

Safety precaution revision as of June 2017.

Introduction .............................................................................................................. 1-1

Table of contents

Welcome .............................................................................................................................. 1-1

Extended warranty ............................................................................................................... 1-1

Contact information .............................................................................................................. 1-2

Product documentation and drivers ..................................................................................... 1-2

Organization of manual sections .......................................................................................... 1-3

Key features ......................................................................................................................... 1-4

Standard accessories ........................................................................................................... 1-5

Optional accessories ............................................................................................................ 1-6

Available services ................................................................................................................ 1-6

General ratings ..................................................................................................................... 1-7

Terminology in this manual .................................................................................................. 1-7

General operation .................................................................................................... 2-1

Front-panel overview ............................................................................................................ 2-1

Rear-panel overview ............................................................................................................ 2-3

Front-panel user interface .................................................................................................... 2-4

Startup screen ........................................................................................................................... 2-4

Home screens ........................................................................................................................... 2-4

Power supply menu overview.................................................................................................. 2-19

Battery test menu overview ..................................................................................................... 2-32

Battery simulator menu overview ............................................................................................ 2-42

Adjusting the backlight brightness and timer ........................................................................... 2-51

Installing the system ........................................................................................................... 2-52

Bumpers .................................................................................................................................. 2-52

Dimensions ............................................................................................................................. 2-53

Power the instrument on and off ............................................................................................. 2-58

Test connections ................................................................................................................ 2-61

Front-panel connector ............................................................................................................. 2-62

Rear-panel output mating connector ....................................................................................... 2-63

Two-wire local sense connection ............................................................................................ 2-63

Four-wire sense connection .................................................................................................... 2-64

Open leads detection .............................................................................................................. 2-66

Reversed sense leads ............................................................................................................. 2-67

Remote communications interfaces ................................................................................... 2-68

Supported remote interfaces ................................................................................................... 2-69

GPIB communications ............................................................................................................. 2-69

LAN communications .............................................................................................................. 2-72

USB communications .............................................................................................................. 2-88

How to install the Keithley I/O Layer ....................................................................................... 2-92

Set voltage and current limit .............................................................................................. 2-93

Constant voltage (CV) and constant current (CC) mode ......................................................... 2-94

Select a measurement function ......................................................................................... 2-96

Table of contents Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual

Power supply ........................................................................................................................... 2-96

Battery test .............................................................................................................................. 2-97

Battery simulator ..................................................................................................................... 2-97

Select a specific measurement range ................................................................................ 2-97

Selecting a specific measurement range ................................................................................ 2-98

Using autoranging for current measurements ......................................................................... 2-99

Protection ......................................................................................................................... 2-100

Overvoltage protection .......................................................................................................... 2-101

Overcurrent protection .......................................................................................................... 2-102

Overtemperature protection .................................................................................................. 2-103

Overprotection error .............................................................................................................. 2-103

Maximum voltage limits ......................................................................................................... 2-104

Saving setups ................................................................................................................... 2-105

Save a user setup ................................................................................................................. 2-105

Recall a user setup ............................................................................................................... 2-106

Specify a default setup .......................................................................................................... 2-107

Using the event log .......................................................................................................... 2-107

Information provided for each event log entry ....................................................................... 2-107

Save the event log to an external flash drive ........................................................................ 2-108

Clear the event log ................................................................................................................ 2-108

System information .......................................................................................................... 2-108

Instrument sounds ............................................................................................................ 2-109

Resets .............................................................................................................................. 2-109

Reset the instrument ............................................................................................................. 2-110

Reset default values .............................................................................................................. 2-110

Functions and features ............................................................................................ 3-1

Instrument access ................................................................................................................ 3-1

Changing the instrument access mode ..................................................................................... 3-2

Changing the password ............................................................................................................ 3-2

Graph ................................................................................................................................... 3-3

Changing the window position and zoom .................................................................................. 3-3

Adjusting the scale and offset of the Y-axis .............................................................................. 3-4

Graphing the battery test function ............................................................................................. 3-6

Graphing the battery simulation function ................................................................................... 3-7

Output delay, slew rate, and source delay ........................................................................... 3-8

Output delay .............................................................................................................................. 3-8

Slew rate ................................ ................................................................ ................................... 3-9

Source delay ........................................................................................................................... 3-10

Data buffer ......................................................................................................................... 3-11

Effects of reset and power cycle on buffer .............................................................................. 3-11

Buffer fill status ........................................................................................................................ 3-12

Setting reading buffer size and buffer mode............................................................................ 3-12

Viewing and saving buffer content .......................................................................................... 3-14

Configuring the statistics applied to data in the buffer ............................................................. 3-18

Clearing the buffer ................................................................................................................... 3-21

Automatically clearing a buffer ................................................................................................ 3-21

Digital I/O ........................................................................................................................... 3-22

Digital I/O port ......................................................................................................................... 3-22

Configuring digital I/O lines ..................................................................................................... 3-27

Trigger model ..................................................................................................................... 3-30

Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual Table of contents

Idle and initiate ........................................................................................................................ 3-31

Arm layer ................................................................................................................................. 3-31

Trigger layer ............................................................................................................................ 3-31

Source, source delay, and measure actions ........................................................................... 3-32

Counter ................................................................................................................................... 3-32

Meter complete ....................................................................................................................... 3-32

Running the trigger model ....................................................................................................... 3-33

Level trigger ....................................................................................................................... 3-35

Configuring a voltage level trigger ........................................................................................... 3-35

Configuring a current level trigger ........................................................................................... 3-37

List operation ...................................................................................................................... 3-39

Configuring a list ..................................................................................................................... 3-40

Importing a list from an external USB flash drive .................................................................... 3-42

Exporting a list to an external USB flash drive ........................................................................ 3-43

Configuring and running a list.................................................................................................. 3-43

Aborting a list .......................................................................................................................... 3-53

Sink operation .................................................................................................................... 3-54

Battery test ......................................................................................................................... 3-55

Battery charging and discharging ............................................................................................ 3-56

Battery discharging test ........................................................................................................... 3-57

Battery charging test ............................................................................................................... 3-59

Generating and editing a battery model .................................................................................. 3-60

ESR measurement .................................................................................................................. 3-63

A-H measurement ................................................................................................................... 3-66

Capacitance measurement ..................................................................................................... 3-69

Battery simulation ............................................................................................................... 3-70

Battery simulation settings ...................................................................................................... 3-70

Simulating a battery ................................................................................................................ 3-71

Measurement optimization ...................................................................................... 4-1

Introduction .......................................................................................................................... 4-1

Optimizing either measurement accuracy or speed ............................................................ 4-1

Resolution ................................................................................................................................. 4-2

NPLC ........................................................................................................................................ 4-4

Autozero measurements ........................................................................................................... 4-5

Displayed digits ......................................................................................................................... 4-6

Filtering measurement data....................................................................................................... 4-7

Math calculations that you can apply to measurements .................................................... 4-11

mx+b ....................................................................................................................................... 4-11

Setting mx+b math operations ................................................................................................ 4-12

Relative offset .................................................................................................................... 4-13

Establishing a relative offset value .......................................................................................... 4-13

Displayed measurements................................................................................................... 4-15

Select the source of readings .................................................................................................. 4-17

ESR measurement ............................................................................................................. 4-18

Introduction to the ESR measurement .................................................................................... 4-18

Measuring ESR in the battery test function ............................................................................. 4-20

A-H measurement .............................................................................................................. 4-21

Introduction to the A-H measurement ..................................................................................... 4-21

Measuring A-H in the battery test function .............................................................................. 4-22

Table of contents Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual

Application examples .............................................................................................. 5-1

Simple voltage output and current measurement ................................................................ 5-1

Equipment required ................................................................................................................... 5-1

Set up remote communications ................................................................................................. 5-1

Device connections ................................................................................................................... 5-2

Set the voltage and current limit ................................................................................................ 5-2

Configure and execute a 10-step linear list sweep .............................................................. 5-3

Equipment required ................................................................................................................... 5-3

Set up remote communications ................................................................................................. 5-4

Device connections ................................................................................................................... 5-4

Configure a 10-step linear list sweep ........................................................................................ 5-4

Execute a 10-step linear list sweep ........................................................................................... 5-6

Perform a fast current load measurement ........................................................................... 5-7

Equipment required ................................................................................................................... 5-7

Set up remote communications ................................................................................................. 5-8

Device connections ................................................................................................................... 5-8

Measure the fast current load changes ................................................................................... 5-10

Battery test ......................................................................................................................... 5-13

Equipment required ................................................................................................................. 5-13

Device connections ................................................................................................................. 5-13

Test a battery and generate a battery model........................................................................... 5-13

Battery simulation test ........................................................................................................ 5-16

Equipment required ................................................................................................................. 5-16

Device connections ................................................................................................................. 5-16

Simulate a battery with the 2281S ........................................................................................... 5-17

Explanations of the test ........................................................................................................... 5-18

Introduction to SCPI commands ............................................................................. 6-1

Introduction to SCPI ............................................................................................................. 6-1

Command messages ................................................................................................................ 6-1

Command execution rules......................................................................................................... 6-2

SCPI command programming notes .................................................................................... 6-2

SCPI command formatting ........................................................................................................ 6-2

Using the SCPI command reference ......................................................................................... 6-5

SCPI command reference ........................................................................................ 7-1

Common commands ............................................................................................................ 7-1

*CLS .......................................................................................................................................... 7-2

*ESE ......................................................................................................................................... 7-3

*ESR? ....................................................................................................................................... 7-4

*IDN? ........................................................................................................................................ 7-4

*LANG? ..................................................................................................................................... 7-5

*OPC ......................................................................................................................................... 7-6

*RCL ......................................................................................................................................... 7-6

*RST ......................................................................................................................................... 7-7

*SAV ......................................................................................................................................... 7-7

*SRE ......................................................................................................................................... 7-8

*STB? ........................................................................................................................................ 7-9

*TRG ......................................................................................................................................... 7-9

*TST? ...................................................................................................................................... 7-10

*WAI ........................................................................................................................................ 7-10

:ABORt[n] ................................................................................................................................ 7-12

Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual Table of contents

:CONFigure[n]:<function> ....................................................................................................... 7-13

:ENTRy[n]:FUNCtion ............................................................................................................... 7-14

:FETCh[n]? .............................................................................................................................. 7-15

:FORCe:TRIGger .................................................................................................................... 7-16

:FORMat:ELEMents ................................................................................................................ 7-17

:MEASure[n]:<function>? ........................................................................................................ 7-18

:READ[n]? ............................................................................................................................... 7-20

ARM subsystem ................................................................................................................. 7-21

:ARM[:SEQuence[n]]:COUNt .................................................................................................. 7-21

:ARM[:SEQuence[n]]:SOURce ................................................................................................ 7-22

BATTery subsystem ........................................................................................................... 7-23

:BATTery[n]:DATA:CLEar ....................................................................................................... 7-23

:BATTery[n]:DATA:DATA? ...................................................................................................... 7-23

:BATTery[n]:DATA:DATA:SELected? ..................................................................................... 7-25

:BATTery[n]:DATA:SAVE ........................................................................................................ 7-26

:BATTery:DIGital:LINE<line_index>:CONFigure ..................................................................... 7-27

:BATTery:DIGital:LINE<n>:EDGe ........................................................................................... 7-28

:BATTery:DIGital:LINE<n>:MANual:INPut:DATA? .................................................................. 7-28

:BATTery[n]:MODel:LOAD:USB .............................................................................................. 7-29

:BATTery[n]:MODel<modelindex>:<element>......................................................................... 7-30

:BATTery[n]:MODel<modelindex>:<element>:APPend .......................................................... 7-31

:BATTery[n]:MODel<modelindex>:<element>:SIMPlify .......................................................... 7-32

:BATTery[n]:MODel<modelindex>:<element>:STEPs? .......................................................... 7-33

:BATTery[n]:MODel<modelindex>:ROW<rowindex> .............................................................. 7-34

:BATTery[n]:MODel:RCL ......................................................................................................... 7-35

:BATTery[n]:MODel:SAVE:INTernal ........................................................................................ 7-36

:BATTery[n]:MODel:SAVE:USB .............................................................................................. 7-37

:BATTery[n]:SIMulator:CAPacity? ........................................................................................... 7-37

:BATTery[n]:SIMulator:CAPacity:LIMit .................................................................................... 7-38

:BATTery[n]:SIMulator:CURRent? .......................................................................................... 7-39

:BATTery[n]:SIMulator:CURRent:LIMit .................................................................................... 7-39

:BATTery[n]:SIMulator:CURRent:PROTection[:LEVel] ........................................................... 7-40

:BATTery[n]:SIMulator:HV ....................................................................................................... 7-41

:BATTery[n]:SIMulator:LV ....................................................................................................... 7-42

:BATTery[n]:SIMulator:METHod .............................................................................................. 7-43

:BATTery[n]:SIMulator:RESistance? ....................................................................................... 7-44

:BATTery[n]:SIMulator:RESistance:OFFSet............................................................................ 7-44

:BATTery[n]:SIMulator:SAMPle:INTerval ................................................................................ 7-45

:BATTery[n]:SIMulator:SOC .................................................................................................... 7-46

:BATTery[n]:SIMulator:TVOLtage? ......................................................................................... 7-47

:BATTery[n]:SIMulator:TVOLtage:PROTection[:LEVel] .......................................................... 7-47

:BATTery[n]:SIMulator:VOC .................................................................................................... 7-48

:BATTery[n]:SIMulator:VOC:EMPTy ....................................................................................... 7-49

:BATTery[n]:SIMulator:VOC:FULL .......................................................................................... 7-50

:BATTery[n]:TEST:MEASure:EVOC? ..................................................................................... 7-51

:BATTery[n]:TEST:SENSe:AH:ESRInterval ............................................................................ 7-51

:BATTery[n]:TEST:SENSe:AH:EXECute................................................................................. 7-52

:BATTery[n]:TEST:SENSe:AH:GMODel:RANGe .................................................................... 7-52

:BATTery[n]:TEST:SENSe:AH:GMODel:SAVE:INTernal ........................................................ 7-53

:BATTery[n]:TEST:SENSe:AH:GMODel:SAVE:USB .............................................................. 7-54

:BATTery[n]:TEST:SENSe:AH:ILIMit ...................................................................................... 7-55

:BATTery[n]:TEST:SENSe:AH[:LEVel]? .................................................................................. 7-55

:BATTery[n]:TEST:SENSe:AH:VFULl ..................................................................................... 7-56

:BATTery[n]:TEST:SENSe:EVOC:DELAy ............................................................................... 7-56

:BATTery[n]:TEST:SENSe:SAMPle:INTerval .......................................................................... 7-57

:BATTery[n]:TEST[:SOURce]:CURRent:END ......................................................................... 7-58

:BATTery[n]:TEST[:SOURce]:CURRent:LIMit:SOURce .......................................................... 7-59

:BATTery[n]:TEST[:SOURce]:CURRent:PROTection[:LEVel]................................................. 7-60

:BATTery[n]:TEST[:SOURce]:HV ............................................................................................ 7-61

:BATTery[n]:TEST[:SOURce]:LV ............................................................................................ 7-62

Table of contents Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual

:BATTery[n]:TEST[:SOURce]:VOLTage[:LEVel] ..................................................................... 7-63

:BATTery[n]:TEST[:SOURce]:VOLTage:LIMit ......................................................................... 7-64

:BATTery[n]:TEST[:SOURce]:VOLTage:PROTection[:LEVel]................................................. 7-65

:BATTery[n]:TRACe:TRIGger:CURRent:DIRection ................................................................. 7-66

:BATTery[n]:TRACe:TRIGger:CURRent[:LEVel] ..................................................................... 7-66

:BATTery[n]:TRACe:TRIGger:CURRent:STATe ..................................................................... 7-67

:BATTery[n]:TRACe:CLEar ..................................................................................................... 7-67

:BATTery[n]:TRACe:DATA? .................................................................................................... 7-68

:BATTery[n]:TRACe:DATA:SELected? ................................................................................... 7-70

:BATTery[n]:TRACe:SAVE ...................................................................................................... 7-71

:BATTery[n]:TRACe:TRIGger:OCCur? ................................................................................... 7-72

:BATTery[n]:TRACe:TRIGger:OFFSet .................................................................................... 7-72

:BATTery[n]:TRACe:TRIGger:VOLTage:DIRection ................................................................. 7-73

:BATTery[n]:TRACe:TRIGger:VOLTage[:LEVel] ..................................................................... 7-73

:BATTery[n]:TRACe:TRIGger:VOLTage:STATe ..................................................................... 7-74

:BATTery[n]:OUTPut:PROTection:CLEar ............................................................................... 7-74

:BATTery[n]:OUTPut:PROTection:TRIPped?.......................................................................... 7-75

:BATTery[n]:OUTPut[:STATe] ................................................................................................. 7-76

:BATTery[n]:STATus? ............................................................................................................. 7-76

CALCulate subsystem ........................................................................................................ 7-77

:CALCulate[1]:<function>:FORMat .......................................................................................... 7-77

:CALCulate[1]:<function>:KMATh:MBFactor ........................................................................... 7-78

:CALCulate[1]:<function>:KMATh:MMFactor .......................................................................... 7-79

:CALCulate[1]:<function>:KMATh:MUNits............................................................................... 7-80

:CALCulate[1]:<function>:STATe ............................................................................................ 7-81

:CALCulate2:DATA? ............................................................................................................... 7-82

:CALCulate2:FORMat ............................................................................................................. 7-84

:CALCulate2:FORMat:ELEMents ............................................................................................ 7-86

:CALCulate2:FUNCtion ........................................................................................................... 7-87

:CALCulate2:IMMediate .......................................................................................................... 7-88

:CALCulate2:STATe ................................................................................................................ 7-90

CALibration subsystem ...................................................................................................... 7-91

:CALibration:PROTected:CANCel ........................................................................................... 7-91

:CALibration:PROTected:CODE ............................................................................................. 7-92

:CALibration:PROTected:COUNt? .......................................................................................... 7-92

:CALibration:PROTected:DATA? ............................................................................................ 7-93

:CALibration:PROTected:DATE .............................................................................................. 7-93

:CALibration:PROTected[:DC[n]]:STEP<step> ....................................................................... 7-94

:CALibration:PROTected[:DC[n]]:STEP<step>:DATA ............................................................. 7-96

:CALibration:PROTected:SAVE .............................................................................................. 7-98

:CALibration:PROTected:STATe ............................................................................................. 7-99

Digital subsystem ............................................................................................................. 7-100

:DIGital:LINE<n>:FUNCtion .................................................................................................. 7-100

:DIGital:LINE<n>:MANual:INPut:DATA? ............................................................................... 7-101

DISPlay subsystem .......................................................................................................... 7-102

:DISPlay:BRIGhtness ............................................................................................................ 7-102

:DISPlay:CLEar ..................................................................................................................... 7-103

:DISPlay:SCREen ................................................................................................................. 7-103

:DISPlay:USER:TEXT[:DATA] ............................................................................................... 7-104

INITiate subsystem .......................................................................................................... 7-105

:INITiate[n]:CONTinuous ....................................................................................................... 7-105

:INITiate[n][:IMMediate] ......................................................................................................... 7-106

MMEMory subsystem ....................................................................................................... 7-106

:MMEMory:LOAD:SETup ................................................................ ...................................... 7-106

:MMEMory:SAVE:SETup ...................................................................................................... 7-107

OUTPut subsystem .......................................................................................................... 7-108

Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual Table of contents

:OUTPut:DELay:FALLing ...................................................................................................... 7-108

:OUTPut:DELay:RISing ......................................................................................................... 7-109

:OUTPut:DELay:STATe ........................................................................................................ 7-110

:OUTPut:PROTection:CLEar................................................................................................. 7-111

:OUTPut:PROTection:TRIPped?[<channel>] ........................................................................ 7-112

:OUTPut[:STATe] .................................................................................................................. 7-113

SENSe subsystem ........................................................................................................... 7-114

:SENSe[n]:FUNCtion ............................................................................................................. 7-114

:SENSe[n]:<function>:AVERage:COUNt .............................................................................. 7-115

:SENSe[n]:<function>:AVERage[:STATe] ............................................................................. 7-116

:SENSe[n]:<function>:AVERage:TCONtrol ........................................................................... 7-117

:SENSe[n]:<function>:AVERage:WINDow ............................................................................ 7-118

:SENSe[n]:<function>:DIGits ................................................................................................. 7-119

:SENSe[n]:<function>:NPLCycles ......................................................................................... 7-120

:SENSe[n]:<function>:RANGe .............................................................................................. 7-121

:SENSe[n]:<function>:RANGe:AUTO ................................................................................... 7-122

:SENSe[n]:<function>:REFerence ......................................................................................... 7-123

:SENSe[n]:<function>:REFerence:ACQuire .......................................................................... 7-124

:SENSe[n]:<function>:REFerence:STATe ............................................................................ 7-125

:SENSe[n]:<function>:RESolution ......................................................................................... 7-126

SOURce subsystem ......................................................................................................... 7-127

[:SOURce[n]]:DELay ............................................................................................................. 7-127

[:SOURce[n]]:DELay:STATe ................................................................................................. 7-128

[:SOURce[n]]:<function>:PROTection[:LEVel] ...................................................................... 7-129

[:SOURce[n]]:<function>[:LEVel][:IMMediate][:AMPLitude] ................................................... 7-130

[:SOURce[n]]:VOLTage:LIMit[:AMPLitude] ........................................................................... 7-131

[:SOURce[n]]:VOLTage:SLEW:RISing .................................................................................. 7-132

[:SOURce[n]]:VOLTage:SLEW:FALLing ............................................................................... 7-133

[:SOURce[n]]:LIST<listNumber>:<element> ......................................................................... 7-134

[:SOURce[n]]:LIST<listNumber>:<element>:APPend ........................................................... 7-135

[:SOURce[n]]:LIST<listNumber>:<element>:POINts? ........................................................... 7-136

[:SOURce[n]]:LIST:END:ZERO ............................................................................................. 7-137

[:SOURce[n]]:LIST:HTIMe ..................................................................................................... 7-137

[:SOURce[n]]:LIST:LOAD:USB ............................................................................................. 7-138

[:SOURce[n]]:LIST:MCOMPlete ............................................................................................ 7-139

[:SOURce[n]]:LIST:RCL ........................................................................................................ 7-140

[:SOURce[n]]:LIST:SAVE:INTernal ....................................................................................... 7-143

[:SOURce[n]]:LIST:SAVE:USB .............................................................................................. 7-144

[:SOURce[n]]:LIST:STATe .................................................................................................... 7-145

STATus subsystem .......................................................................................................... 7-148

:STATus:MEASurement[:EVENt]? ........................................................................................ 7-148

:STATus:MEASurement:ENABle .......................................................................................... 7-148

:STATus:MEASurement:INSTrument[:EVENt]? .................................................................... 7-149

:STATus:MEASurement:INSTrument:ENABle ...................................................................... 7-149

:STATus:MEASurement:INSTrument:ISUMmary[:EVENt]? .................................................. 7-150

:STATus:MEASurement:INSTrument:ISUMmary:ENABle .................................................... 7-151

:STATus:MEASurement:INSTrument:ISUMmary:CONDition? .............................................. 7-152

:STATus:OPERation[:EVENt]? .............................................................................................. 7-152

:STATus:OPERation:ENABle ................................................................................................ 7-153

:STATus:OPERation:INSTrument[:EVENt]? ......................................................................... 7-153

:STATus:OPERation:INSTrument:ENABle ........................................................................... 7-154

:STATus:OPERation:INSTrument:ISUMmary[:EVENt]? ....................................................... 7-154

:STATus:OPERation:INSTrument:ISUMmary:ENABle .......................................................... 7-155

:STATus:OPERation:INSTrument:ISUMmary:CONDition? ................................................... 7-156

:STATus:PRESet .................................................................................................................. 7-156

:STATus:QUEStionable[:EVENt]? ......................................................................................... 7-157

:STATus:QUEStionable:ENABle ........................................................................................... 7-158

:STATus:QUEStionable:INSTrument[:EVENt]?..................................................................... 7-158

:STATus:QUEStionable:INSTrument:ENABle ....................................................................... 7-159

Table of contents Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual

:STATus:QUEStionable:INSTrument:ISUMmary[:EVENt]? ................................................... 7-160

:STATus:QUEStionable:INSTrument:ISUMmary:ENABle ..................................................... 7-160

:STATus:QUEStionable:INSTrument:ISUMmary:CONDition? .............................................. 7-161

SYSTem subsystem ......................................................................................................... 7-162

:SYSTem:AZERo[n][:STATe] ................................................................................................ 7-162

:SYSTem:BEEPer:ERRor[:STATe] ....................................................................................... 7-163

:SYSTem:COMMunication:ABORt ........................................................................................ 7-163

:SYSTem:COMMunication:LAN:CONFigure ......................................................................... 7-164

:SYSTem:COMMunication:LAN:MACaddress? ..................................................................... 7-165

:SYSTem:DATE .................................................................................................................... 7-166

:SYSTem:ERRor? ................................................................................................................. 7-166

:SYSTem:ERRor:CLEar ........................................................................................................ 7-167

:SYSTem:ERRor:CODE? ...................................................................................................... 7-167

:SYSTem:ERRor:COUNt?..................................................................................................... 7-168

:SYSTem:EVENtlog:SAVE .................................................................................................... 7-168

:SYSTem:GPIB:ADDRess..................................................................................................... 7-169

:SYSTem:KCLick .................................................................................................................. 7-170

:SYSTem:LOCal .................................................................................................................... 7-170

:SYSTem:LFRequency? ....................................................................................................... 7-171

:SYSTem:PASSword:LOCK .................................................................................................. 7-171

:SYSTem:PASSword:MODE ................................................................................................. 7-172

:SYSTem:PASSword:NEW ................................................................................................... 7-173

:SYSTem:PASSword:UNLock ................................................................ ............................... 7-174

:SYSTem:POSetup:STATe ................................................................................................... 7-174

:SYSTem:PRESet ................................................................................................................. 7-175

:SYSTem:RWLock ................................................................................................................ 7-176

:SYSTem:TIME ..................................................................................................................... 7-176

:SYSTem:VERSion? ............................................................................................................. 7-177

TRACe subsystem ........................................................................................................... 7-177

:DATA[n]:CLEar .................................................................................................................... 7-177

:DATA[n]:CLEar:AUTO ......................................................................................................... 7-178

:DATA[n]:DATA? ................................................................................................................... 7-178

:DATA[n]:DATA:SELected?................................................................................................... 7-180

:DATA[n]:FEED ..................................................................................................................... 7-182

:DATA[n]:FEED:CONTrol ...................................................................................................... 7-183

:DATA[n]:POINts ................................................................................................................... 7-184

:DATA[n]:POINts:ACTual? .................................................................................................... 7-184

:DATA[n]:SAVE ..................................................................................................................... 7-185

:TRACe[n]:CLEar .................................................................................................................. 7-186

:TRACe[n]:CLEar:AUTO ....................................................................................................... 7-186

:TRACe[n]:DATA? ................................................................................................................. 7-187

:TRACe[n]:DATA:SELected? ................................................................................................ 7-188

:TRACe[n]:FEED ................................................................................................................... 7-190

:TRACe[n]:FEED:CONTrol .................................................................................................... 7-191

:TRACe[n]:POINts ................................................................................................................. 7-192

:TRACe[n]:POINts:ACTual? .................................................................................................. 7-192

:TRACe[n]:SAVE ................................................................................................................... 7-193

:TRACe[n]:TRIGger:CURRent:DIRection .............................................................................. 7-194

:TRACe[n]:TRIGger:CURRent[:LEVel] ............................................................................ 7-194

:TRACe[n]:TRIGger:CURRent:STATe .................................................................................. 7-195

:TRACe[n]:TRIGger:OCCur? ................................................................................................. 7-195

:TRACe[n]:TRIGger:OFFSet ................................................................................................. 7-196

:TRACe[n]:TRIGger:VOLTage:DIRection .............................................................................. 7-196

:TRACe[n]:TRIGger:VOLTage[:LEVel] .................................................................................. 7-197

:TRACe[n]:TRIGger:VOLTage:STATe .................................................................................. 7-197

TRIGger subsystem ......................................................................................................... 7-198

:TRIGger[:SEQuence[n]]:COUNt ........................................................................................... 7-198

:TRIGger[:SEQuence[n]]:SAMPle:COUNt ............................................................................. 7-199

Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual Table of contents

:TRIGger[:SEQuence[n]]:SOURce ........................................................................................ 7-200

Troubleshooting guide ............................................................................................ 8-1

Introduction .......................................................................................................................... 8-1

Contacting support ............................................................................................................... 8-1

What to do if the power supply does not turn on ................................................................. 8-2

LAN troubleshooting suggestions ........................................................................................ 8-3

Error summary ..................................................................................................................... 8-3

Next steps ................................................................................................................. 9-1

Additional 2281S information ............................................................................................... 9-1

Maintenance ............................................................................................................. A-1

Introduction .......................................................................................................................... A-1

Line fuse replacement .......................................................................................................... A-1

Upgrading the firmware ........................................................................................................ A-2

From the front panel .................................................................................................................. A-3

Perform DIN VDE 701 test ................................................................................................... A-4

Cleaning the front-panel display .......................................................................................... A-4

Verification ............................................................................................................... B-1

Overview .............................................................................................................................. B-1

Test record ........................................................................................................................... B-1

DC voltage setting accuracy with remote sense ........................................................................ B-3

DC voltage setting accuracy without remote sense ................................................................... B-4

DC voltage readback accuracy with remote sense ................................................................... B-5

DC voltage readback accuracy without remote sense .............................................................. B-6

DC voltage line regulation without remote sense ...................................................................... B-6

DC voltage load regulation without remote sense ..................................................................... B-6

DC overvoltage protection ......................................................................................................... B-7

Maximum continuous average sink current ............................................................................... B-7

Sink current readback accuracy (1 A range) ............................................................................. B-8

Sink current readback accuracy (10 mA range) ........................................................................ B-8

Sink current readback accuracy (100 mA range) ...................................................................... B-9

DC current accuracy ............................................................................................................... B-10

DC current readback accuracy (10 A range) ........................................................................... B-11

DC current readback accuracy (1 A range) ............................................................................. B-11

DC current readback accuracy (10 mA range) ........................................................................ B-12

DC current readback accuracy (100 mA range) ...................................................................... B-12

DC current line regulation........................................................................................................ B-13

DC current load regulation ...................................................................................................... B-13

DC overcurrent protection ....................................................................................................... B-13

Voltage noise at 20 MHz ......................................................................................................... B-14

Current noise at 20 MHz ......................................................................................................... B-14

Performance verification procedures ................................................................................. B-15

Performance verification conditions ........................................................................................ B-15

Required equipment ................................................................................................................ B-16

Check DC voltage setting readback accuracy with remote sense ........................................... B-16

Table of contents Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual

Check DC voltage setting accuracy without remote sense ..................................................... B-19

Check DC voltage readback accuracy without remote sense ................................................. B-21

Check DC voltage line regulation ............................................................................................ B-23

Check DC voltage load regulation ........................................................................................... B-25

Check DC overvoltage protection ............................................................................................ B-26

Check sink current capability................................................................................................... B-27

Check sink current readback accuracy (1 A range) ................................................................. B-28

Check sink current readback accuracy (100 mA and 10 mA ranges) ...................................... B-30

Check DC current accuracy .................................................................................................... B-32

Check DC current readback accuracy (10 A and 1 A ranges) ................................................. B-34

Check DC current readback accuracy (100 mA and 10 mA ranges) ....................................... B-36

Check DC current line regulation ............................................................................................ B-38

Check DC current load regulation ........................................................................................... B-40

Check overcurrent protection .................................................................................................. B-41

Check voltage noise (20 MHz) ................................................................................................ B-42

Check current noise (20 MHz) ................................................................................................. B-44

Calibration and adjustment ..................................................................................... C-1

Overview .............................................................................................................................. C-1

Environmental conditions ..................................................................................................... C-1

Warmup period .......................................................................................................................... C-2

Line power................................................................................................................................. C-2

Calibration considerations .................................................................................................... C-2

Calibration cycle ........................................................................................................................ C-2

Required equipment .................................................................................................................. C-3

Characterization shunts ............................................................................................................ C-4

Calibration connection.......................................................................................................... C-6

Voltage calibration connections................................................................................................. C-7

Current calibration connections ................................................................................................. C-8

Sink current calibration connections ........................................................................................ C-11

Front-panel calibration procedure ...................................................................................... C-12

Voltage calibration ................................................................................................................... C-12

Low-current calibration ............................................................................................................ C-13

High-current calibration ........................................................................................................... C-15

Low-sink current calibration..................................................................................................... C-16

High-sink current calibration .................................................................................................... C-18

Saving calibration constants from the front panel.................................................................... C-19

Remote calibration procedure ............................................................................................ C-20

Remote voltage calibration ...................................................................................................... C-21

Remote low-current calibration ................................................................................................ C-22

Remote high-current calibration .............................................................................................. C-23

Remote low-sink current calibration ........................................................................................ C-25

Remote high-sink-current calibration ....................................................................................... C-27

Saving calibration constants using SCPI commands .............................................................. C-28

Configure the calibration date ................................................................................................. C-29

Exit the calibration procedure using SCPI commands ............................................................ C-29

Change the calibration password ....................................................................................... C-30

Calibration constants .......................................................................................................... C-31

Status model ............................................................................................................ D-1

Overview .............................................................................................................................. D-1

Status model structure .............................................................................................................. D-3

Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual Table of contents

Programming and reading registers ..................................................................................... D-5

Programming enable registers .................................................................................................. D-5

Reading the registers ................................................................................................................ D-6

Clearing the registers ........................................................................................................... D-6

Status byte and service request ........................................................................................... D-7

Status Byte Register ................................................................................................................. D-7

Service Request Enable Register ............................................................................................. D-8

Status register sets .............................................................................................................. D-9

Register bit descriptions ............................................................................................................ D-9

Event registers ........................................................................................................................ D-20

Event enable registers ............................................................................................................ D-20

Condition registers .................................................................................................................. D-20

Queues ............................................................................................................................... D-20

Output queue .......................................................................................................................... D-20

Error queue ............................................................................................................................. D-21

Serial polling and SRQ ....................................................................................................... D-21

Status model programming examples ............................................................................... D-22

SRQ when reading buffer becomes full ................................................................................... D-22

SRQ when trigger model is finished ........................................................................................ D-23

In this section:

Welcome ................................ ................................ .................. 1-1

Extended warranty ................................................................... 1-1

Contact information .................................................................. 1-2

Product documentation and drivers .......................................... 1-2

Organization of manual sections .............................................. 1-3

Key features ............................................................................. 1-4

Standard accessories ............................................................... 1-5

Optional accessories ................................................................ 1-6

Available services .................................................................... 1-6

General ratings ......................................................................... 1-7

Terminology in this manual ...................................................... 1-7

Section 1

Introduction

Welcome

Thank you for choosing a Keithley Instruments product. The 2281S Precision DC Power Supply and
Battery Simulator is a high-sensitivity, low-noise, programmable instrument that sources stable,
low-noise voltage and can monitor load currents over a wide dynamic range, from amperes to
nanoamperes.

In addition to serving as a power supply, it can conduct battery testing by charging and discharging
the battery under test and creating a model for the battery. The 2281S can also simulate batteries to
facilitate tests conducted on the products supplied by batteries.

The high-resolution, 4.3-inch TFT color display presents numerous parameters that describe the state
of the instrument to enable you to get the most information from your measurements.

Extended warranty

Additional years of warranty coverage are available on many products. These valuable contracts
protect you from unbudgeted service expenses and provide additional years of protection at a fraction
of the price of a repair. Extended warranties are available on new and existing products. Contact your
local Keithley Instruments office, sales partner, or distributor for details.

Section 1: Introduction Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual

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Contact information

If you have any questions after you review the information in this documentation, please contact your
local Keithley Instruments office, sales partner, or distributor. You can also call the corporate
headquarters of Keithley Instruments (toll-free inside the U.S. and Canada only) at 1-800-935-5595,
or from outside the U.S. at [phone]. For worldwide contact numbers, visit the Keithley

Instruments website (tek.com/keithley).

Product documentation and drivers

The following documentation and drivers for the 2281S are available for download from the Keithley

Instruments support website (tek.com/support).

Quick Start Guide: Provides unpacking instructions, describes basic connections, reviews basic

operation information, and provides a quick test procedure to ensure the instrument is
operational.

Reference Manual: Includes advanced operation topics, maintenance information,

troubleshooting procedures, and in-depth descriptions of programming commands.

Accessories information: Documentation for accessories that are available for the 2281S.
Drivers and release notes: IVI Instrument Driver, National Instruments LabVIEW™ driver, and

related release notes.

Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual Section 1: Introduction

077114601 / March 2019 1-3

Organization of manual sections

The information in this manual is organized into the following major categories:

General operation: Describes the components of the instrument and basic operation.
Functions and features: Describes features and functions, such as measure operations, battery test,

battery simulation, list mode, reading buffers, triggering, the digital I/O port, graph function, output
delay, and slew rate.

Measurement optimization: Describes best practices and recommended procedures that can
increase measurement speed, accuracy, and sensitivity.

Application examples: Contains examples of several applications that you can use as a starting
point for your own application.

Introduction to SCPI commands: Describes how to control the instrument using SCPI commands.
SCPI command reference: Contains programming notes and an alphabetical listing of all SCPI

commands available for the 2281S.

Troubleshooting guide: Describes the event log and basic LAN troubleshooting.
Next steps: Contains sources of additional information.
Maintenance: Contains information about instrument maintenance, including line fuse replacement

and firmware upgrades.

Verification: Contains performance verification procedures.
Calibration and adjustment: Contains information about instrument calibration from the front panel

and using SCPI commands.
Status model: Describes the 2281S status model.

Section 1: Introduction Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual

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Key features

Model

Description

2281S-20-6

Precision-measurement DC power supply, 20 V, 6 A

The 2281S has three basic functions: High-performance power supply, battery test, and battery
simulation.

As a high-performance power supply:

 High-current resolution and sensitivity to measure a wide range of load currents
 6½-digit measurement resolution to enable a wide range of measurements on a single current range
 Fast current measurements to test or study load current pulses as narrow as 100 μs
 Linear mode, low noise output

As a battery test instrument:

 Battery capacity test with charging and discharging functions
 Battery charge and discharge process and data logging (voltage, current, resistance, and amp-hour

information)

 Generate a battery model based on battery test results
 Measure open-circuit voltage and resistance

As a battery simulator:

 Simulate a real battery based on a battery model
 Dynamic and static simulation mode to simulate battery output
 Intuitive way to show battery capacity and battery voltage on home screen

Other features:

 Color TFT display with icon-based and soft-key user interface
 Data logging and analysis with graphical display and statistics for trend analysis
 GPIB, USB-TMC, and LAN LXI interfaces for automated test development
 Digital I/O for rich trigger functions
 Direct parameter entry using the front-panel keypad, soft keys, or the navigation control
 Front-panel USB-A connector for flash-drive support
 Front and rear inputs with remote sense connections on the rear-panel connector
 Overcurrent, overvoltage, and overtemperature protection
 Compact, 2U, half rack, stackable form factor fits easily in a test rack

Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual Section 1: Introduction

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Standard accessories

Accessory

Part number

Model 2281-001 output mating connector

2281-001

Standard LAN crossover cable

N/A

Quick start guide

See the following table for part numbers.

Certification of calibration

Languages

Part number

English

0713430xx*

Simplified Chinese

0713432xx*

Traditional Chinese

0713433xx*

Japanese

0713431xx*

* Where xx represents the revision number.

You will get one of the following quick start guides.

You will also get one of the following power cords:

Option A0 North America and South America. The factory sets the line-voltage selector switch

to 110 V.

Option A1 Universal Euro. The factory sets the line-voltage selector switch to 220 V.
Option A2 United Kingdom. The factory sets the line-voltage selector switch to 220 V.
Option A3 Australia. The factory sets the line-voltage selector switch to 220 V.
Option A4 Chile, Italy. The factory sets the line-voltage selector switch to 220 V.
Option A5 Switzerland. The factory sets the line-voltage selector switch to 220 V.
Option A6 Japan. The factory sets the line-voltage selector switch to 100 V.
Option A7 Denmark. The factory sets the line-voltage selector switch to 220 V.
Option A8 Israel. The factory sets the line-voltage selector switch to 220 V.
Option A9 Argentina. The factory sets the line-voltage selector switch to 220 V.
Option A10 China. The factory sets the line-voltage selector switch to 220 V.
Option A11 India. The factory sets the line-voltage selector switch to 220 V.

Section 1: Introduction Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual

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Optional accessories

Optional accessory

Part number

Model 2281-001 output mating connector

2281-001

USB cable type A to B, 1 m (3.3 ft)

USB-B-1

Standard LAN crossover cable

N/A

IEEE-488.2 interface board for the PCI bus

KPCI-488LPA

Double-shielded premium IEEE-488 interface cables, 0.5 m (1.6 ft)

7007-05

Double-shielded premium IEEE-488 interface cables, 1 m (3.2 ft)

7007-1

Double-shielded premium IEEE-488 interface cables, 2 m (6.5 ft)

7007-2

Double-shielded premium IEEE-488 interface cables, 3 m (10 ft)

7007-3

Double-shielded premium IEEE-488 interface cables, 4 m (13 ft)

7007-4

Dual fixed rack-mount kit for 2280S and 2281S instruments

4299-14

Model 2450-TLINK trigger link cable

131909200

Service

Model Number

1 additional year of factory warranty beyond the 3-year factory
warranty (total of 4 years)

2281S-20-6-EW

2 additional years of factory warranty beyond the 3-year factory
warranty (total of 5 years)

2281S-20-6-5Y-EW
KeithleyCare 3-year standard calibration plan

C/2281S-20-6-3Y-STD

KeithleyCare 3-year calibration with data plan

C/2281S-20-6-3Y-DATA

KeithleyCare 5-year standard calibration plan

C/2281S-20-6-5Y-STD

KeithleyCare 5-year calibration with data plan

C/2281S-20-6-5Y-DATA

Available services

For the most up-to-date list of available services and accessories, upgrades, and options for your
instrument, visit tek.com/keithley.

Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual Section 1: Introduction

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General ratings

Category

Specification

Supply voltage range

100 V, 120 V, 220 V, 240 V; each range capable of 10% tolerance, 50 Hz or
60 Hz

Selectable by the line-voltage selector switch on the rear panel

Output connections

See Test connections (on page 2-61).

Environmental conditions

For indoor use only

Altitude: Maximum 2000 meters (6562 feet) above sea level
Operating: 0 °C to 40 °C, full accuracy to 80% relative humidity at up to 35 °C,

noncondensing
Storage: -20 °C to 70 °C, 5% to 95% relative humidity at up to 40 °C and 5% to
60% relative humidity above 40 °C at up to 70 °C

Pollution degree: 2

Model

100 VAC/120 VAC source

220 VAC/240 VAC source

2281S-20-6

250 V, 5 A, time delay

250 V, 2.5 A, time delay

Term

Explanation

ESR

Equivalent series resistance

VOC

Open-circuit voltage

Vt

Terminal voltage

Amp-Hour (A-H)

Unit for battery capacity

SOC

State of charge

Battery model

A profile of a battery that contains the information for Voc and ESR in different
states of charge

V-Full

The voltage of the battery when it is fully charged

V-Empty

The voltage of the battery when it is fully discharged

Dynamic

During the dynamic battery simulation, the open voltage and SOC change with
the charging and discharging

Static

During the static battery simulation, the open voltage and SOC stay the same

The general ratings and connections for the 2281S are listed in the following table.

Line fuse characteristics are shown in the following table.

Terminology in this manual

In this section:

Front-panel overview ................................................................ 2-1

Rear-panel overview ................................................................ 2-3

Front-panel user interface ........................................................ 2-4

Installing the system ............................................................... 2-52

Test connections .................................................................... 2-61

Remote communications interfaces ....................................... 2-68

Set voltage and current limit ................................................... 2-93

Select a measurement function .............................................. 2-96

Select a specific measurement range .................................... 2-97

Protection ............................................................................. 2-100

Saving setups ....................................................................... 2-105

Using the event log .............................................................. 2-107

System information .............................................................. 2-108

Instrument sounds ................................................................ 2-109

Resets .................................................................................. 2-109

POWER switch

Turns the instrument on or off. To turn the instrument on, press
the power switch so that it is in the on position (|). To turn it off,
press the power switch so that it is in the off position (O).

Section 2

General operation

Front-panel overview

The front panel of 2281S is shown below. Descriptions of the controls on the front panel follow the
figure.

Figure 1: 2281S front panel

Section 2: General operation Model 2281S-20-6 DC Power Supply and Battery Simulator Reference Manual

2-2 077114601 / March 2019

MENU key

Opens the main menu. Select the icons using the navigation
control and pressing the ENTER key to open battery, source,
measure, views, trigger, and system screens. For details, see

Power supply menu overview (on page 2-19), Battery test menu
overview (on page 2-32), and Battery simulator menu overview

(on page 2-42).

USB port

Saves reading buffer data to a USB flash drive. You can also
store and retrieve scripts to and from a USB flash drive. The flash
drive must be formatted as a FAT or FAT32 drive.

LCD screen

The 2281S has a high-resolution, 4.3-inch color TFT LCD display.
You can access additional interactive screens by pressing the
front-panel MENU key.

Navigation control

Turning the navigation control: Moves the cursor to the left or

the right to highlight a listed value or menu item so that you can
select it.

ENTER key

Selects the highlighted choice or allows you to edit the selected
field.

EXIT key

Returns to the previous screen or closes a dialog box. For
example, press the EXIT key when the main menu is displayed to
return to the home screen. When you are viewing a subscreen
(for example, the Event Log screen), press the EXIT key to return
to the main menu screen.

TRIGGER key

Accesses trigger-related settings and operations. The action of
the TRIGGER key depends on the instrument state.

Soft keys

There are five soft keys located under the display. They provide
access to additional settings on multiple screens. For example,
press the first soft key when the main menu screen is displayed to
move the cursor to the left.

OUTPUT ON/OFF
switch

Turns the output source on or off. The switch illuminates when the
source output is on.

REMOTE LED
indicator

Illuminates when the instrument is controlled through a remote
interface.

LAN LED indicator

Illuminates when the instrument is connected to a local area network
(LAN).

Front-panel
binding posts

Positive, negative, and ground output binding posts for output
connections.

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Rear-panel overview

LAN port

Supports full connectivity on a 10 Mbps or 100 Mbps network. The
2281S is a version 1.4 LXI Core 2011 compliant instrument that
supports TCP/IP and complies with IEEE Std 802.3 (ethernet
LAN). See LAN communications (on page 2-72).

USB port

USB-B connection for communication, control, and data transfer.
For details, see USB communications (on page 2-88).

Power module

The power module contains the AC line receptacle, the power line
fuse, and the line voltage selector switch. For safety precautions
and other details, see Line fuse replacement (on page A-1) and

Power the instrument on and off (on page 2-58).

Digital I/O port

A digital input/output port that detects and outputs digital signals.
The port provides six digital I/O lines. Each output is set high
(+5 V) or low (0 V) and can read high or low logic levels. Each
digital I/O line is an open-drain signal. Refer to Digital I/O (on
page 3-22) for information.

IEEE-488 port

GPIB connection; the default setting for the 2281S is 5. Refer to

GPIB communication (on page 2-69).

Rear output
terminals

Connections for the source outputs and the sense inputs.

The rear panel of the 2281S is shown below; descriptions follow the figure.

Figure 2: 2281S rear panel

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Front-panel user interface

The front-panel user interface gives you quick access to the functions of this instrument. It includes
the startup screen to choose a function, home screens for each of the functions, and menus for the
functions.

The following topics describe the features of the user interface in more detail.

Startup screen

After you turn on the 2281S, you will see the following startup screen.

Figure 3: Startup screen

The 2281S has three functions you can select from the startup screen:

High-precision power supply: Supplies 20 V, 6 ADC source
Battery test: Conducts battery charging and discharging tests to calculate the capacity and

resistance of the battery and create a battery model

Battery simulator: Simulates a battery to determine what the effect the battery has on the device

under test (DUT) in different states.

You can choose a function by turning the navigation control or pressing the soft keys and pressing

Enter to access the respective home screens of the function.

Home screens

Each function has its own home screen. The following topics describe the home screens.

Status and error indicators

The indicators across the top of the home screen contain information about the following instrument
settings and states. Highlight an indicator by turning the navigation control and then pressing ENTER
to get more information about the present state of the instrument.

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Communication settings status indicator

Indicator

Meaning

Local

Instrument is controlled from the front panel.

GPIB

Instrument is communicating through a GPIB interface.

VXI-11

Instrument is communicating using VXI-11.

USBTMC

Instrument is communicating through a USB interface
(firmware version 1.05 and earlier, port number raw socket 5050; firmware version

1.06 and later, port number raw socket 5025).

WebPage

Instrument is communicating through a web page.

Move the focus to the communication indicator using the navigation control and press the ENTER key
to see a list of present communications settings.

Figure 4: 2281S communication status indicator

Instrument communication activity indicator

The activity indicator is located to the right of the communication settings status indicator. When the
instrument is communicating with a remote interface, the up and down arrows flash.

Figure 5: Instrument communication activity indicator

If a service request has been generated, SRQ is displayed to the right of the up and down arrows. You
can configure the instrument to generate a service request (SRQ) when one or more errors or
conditions occur. This indicator stays on until the serial poll byte is read or all the conditions that
caused SRQ are cleared.

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Level trigger enabled indicator

Green bar

Buffer status

Empty

Less than one-quarter full

Less than half full, more than one-quarter full

Less than three-quarter full, more than half full

More than three-quarter full

When a voltage level trigger or current level trigger is enabled, a solid white square indicator is visible
to the left of the Buffer indicator.

When a level trigger is enabled, data is logged to the buffer when the triggering condition is met.

Buffer indicator

The bar next to Buffer indicates how full the buffer is.

Figure 6: Level trigger enabled indicator

Trigger mode settings indicator

This indicator shows the status of the trigger operation.

Figure 7: Trigger indicator

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List and recall settings indicator

This indicator shows the specified list number or recall settings.

Figure 8: List and recall settings indicator

Error and event indicator

Move the focus to the error and event indicator using navigation control and press the ENTER key to
see the present error and event messages. With the focus on the Event Log button, press ENTER to
see the Error and Event Log.

Figure 9: Error and event indicator