Keithley 2461 Quick Start Manual

Safety precautions

Observe the following safety precautions 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 qualified 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 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 Instruments 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 V DC 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, as
defined in the specifications and operating information, and as shown on the
instrument or test fixture panels, or switching card.

When fuses are used in a product, replace with 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.

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

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

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

This symbol indicates a connection terminal to the equipment frame.

If the mercury 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.

WARNING

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

CAUTION

This heading in the user documentation explains hazards that could
damage the instrument. Such damage 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 Instruments. Standard fuses with applicable national
safety approvals may be used if the rating and type are the same. Other components
that are not safety-related may be purchased from other suppliers as long as they are
equivalent to the original component (note that selected parts should be purchased
only through Keithley Instruments to maintain accuracy and functionality of the
product). If you are unsure about the applicability of a replacement component, call a
Keithley Instruments office for information.

To clean an instrument, remove power from the instrument. Use a damp cloth or
mild, water-based cleaner. Clean the exterior of the instrument only. Do not apply
cleaner directly to the instrument or allow liquids to enter or spill on the instrument.
Products that consist of a circuit board with no case or chassis (e.g., 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 and servicing.

Safety precaution revision as of January 2013.

Power and environmental specifications

For indoor use only.

Power supply

100 V to 240 V RMS, 50 Hz to 60 Hz (autosensing)

Maximum VA

350 VA

Operating
altitude

Maximum 2000 m (6562 ft) above sea level

Operating
temperature

0 °C to 50 °C (32 °F to 122 °F), 70 % relative humidity
up to 35 °C (95 °F); derate 3 % relative humidity/°C,
35 °C to 50 °C (95 °F to 122 °F)

Storage
temperature

25 °C to 65 °C (13 °F to 149 °F), 5 % to 90 %
relative humidity noncondensing

Pollution degree

1 or 2

Carefully consider and configure the appropriate output-off
state, and source and compliance levels before connecting the
instrument to a device that can deliver energy. Failure to
consider the output-off state and source and limit levels may
result in damage to the instrument or to the device under test.

Introduction

Thank you for choosing a Keithley Instruments product. The Model
2461 1 kW Pulse Mode Interactive SourceMeter® Instrument is a
precise, low-noise instrument that combines a stable DC power
supply, high-power, true high-current source, electronic load, and
high-impedance multimeter with pulse, contact check, and digitize
capabilities. This instrument features intuitive set up and control,
enhanced signal quality and range, and better resistivity and resistance
capabilities than similar products on the market.

The Model 2461 can source up to 7 A (10 A pulse only) and features
1 µA to 7 A (10 A pulse only) ranges. With 0.012 percent basic
accuracy at 6½-digit resolution, the Model 2461 is a good solution for
testing a wide variety of materials and devices in applications such as
power semiconductors, solar energy, high-brightness LEDs, power
conversion, electrochemistry, batteries, and more.

CD-ROM contents

The CD-ROM that is included with your instrument contains:

 Quick Start Guide (this document): Provides unpacking

instructions, describes basic connections, reviews basic operation
information, and provides a quick test procedure to ensure the
instrument is operational.

 User's Manual: Provides application examples that you can use

as a starting point to create your own applications.

 Reference Manual: Includes advanced operation topics,

maintenance information, troubleshooting procedures,
optimization strategies, and in-depth descriptions of
programming commands.

 KickStart Software Quick Start Guide: Provides instructions to

quickly make measurements and get results without having to
program test scripts.

 Accessories information: Documentation for accessories that

are available for the Model 2461.

For the latest drivers and additional support information, see

http://www.keithley.com/support.

.

Unpack and inspect the instrument

To unpack and inspect the instrument:

1. Inspect the box for damage.

2. Open the top of the box.

3. Remove the bag that contains the documentation, standard
accessories, CD-ROM, and optional accessories.

4. Remove optional accessories (such as rack-mount hardware).

5. Remove the packaging insert.

6. Remove the Model 2461 from the box.

Do not use the front bezel to lift the Model 2461. Using the front
bezel can cause damage to the instrument.

7. Inspect the instrument for any obvious signs of physical damage.
Report any damage to the shipping agent immediately.

You should have received the Model 2461 with the following
accessories, shown in the photograph:

1 Model 8608 Safety Clip-Lead Set
2 USB-B-1 USB Cable, Type A to Type B (1 m)
3 Model 2460-KIT Screw Terminal Connector kit

4 Model CS-1616-3 Mini-clamp II Plug for the interlock
5 Model CA-180-3A CAT5 Crossover Cable for TSP-Link or

Ethernet

6 Power line cord
7 KickStart Quick Start Guide (not shown)

8 Model 2461 Quick Start Guide (this document, not shown)
9 Interactive SourceMeter Instrument Product Information

CD-ROM (not shown)

10 Safety Precautions (not shown)
Refer to the packing list for additional items that might have shipped

with your instrument.

Connect the instrument

Important test system safety information

This product is sold as a stand-alone instrument that may become
part of a system that could contain hazardous voltages and energy
sources. It is the responsibility of the test system designer, integrator,
installer, maintenance personnel, and service personnel to make sure
the system is safe during use and is operating properly.

You must also realize that in many test systems a single fault, such as
a software error, may output hazardous signal levels even when the
system indicates that there is no hazard present.

It is important that you consider the following factors in your system
design and use:

 The international safety standard IEC 61010-1 defines voltages as

hazardous if they exceed 30 V

RMS

and 42.4 V

peak

, or 60 V DC for
equipment rated for dry locations. Keithley Instruments products
are only rated for dry locations.

 Read and comply with the specifications of all instruments in the

system. The overall allowed signal levels may be constrained by
the lowest-rated instrument in the system. For example, if you are

using a 500 V power supply with a 300 V DC rated switch, the
maximum allowed voltage in the system is 300 V DC.

 Make sure any test fixture connected to the system protects the

operator from contact with hazardous voltages, hot surfaces, and
sharp objects. Use shields, barriers, insulation, and safety
interlocks to accomplish this.

 Cover the device under test (DUT) to protect the operator from

flying debris in the event of a system or DUT failure.

 Double-insulate all electrical connections that an operator can

touch. Double insulation ensures the operator is still protected
even if one insulation layer fails. Refer to IEC 61010-1 for
specific requirements.

 Make sure all connections are behind a locked cabinet door or

other barrier. This protects the system operator from accidentally
removing a connection by hand and exposing hazardous voltages.
Use high-reliability fail-safe interlock switches to disconnect
power sources when a test fixture cover is opened.

 Where possible, use automatic handlers so operators are not

required to access the DUT or other potentially hazardous areas.

 Provide training to all users of the system so they understand all

potential hazards and know how to protect themselves from
injury.

 In many systems, when the instrument is powering on, the

outputs may be in an unknown state until they are properly
initialized. Make sure the design can tolerate this situation
without causing operator injury or hardware damage.

To keep users safe, always read and follow all safety warnings
provided with each of the instruments in your system.

Install the instrument

You can use the Model 2461 on a bench or in a rack. Please see the
instructions that came with your rack-mount kit if you are installing
the Model 2461 in a rack.

To prevent damaging heat build-up and ensure specified
performance, make sure there is adequate ventilation and air flow
around the instrument to ensure proper cooling. Do not cover the
ventilation holes on the top, sides, or bottom of the instrument.

Position the instrument so that it is easy to reach any disconnecting
devices, such as the power cord and the power switch.

Wiring the interlock

The Model 2461 is provided with an interlock circuit that must be
positively activated in order for the high-voltage output to be
enabled. The interlock helps facilitate safe operation of the
equipment in a test system. Bypassing the interlock could
expose the operator to hazardous voltages that could result in
personal injury or death.

To perform high-voltage measurements, the Model 2461 interlock
must be connected to an interlock switch. When properly connected,
the safety interlock of the Model 2461 places the outputs of the
instrument in a safe state. When the safety interlock signal is asserted,
all voltage ranges of the instrument are available and the green
front-panel INTERLOCK indicator is on.

When the safety interlock signal is not asserted, the high-voltage
ranges are disabled, limiting the nominal output to less than ±42 V,
and the front-panel INTERLOCK indicator is not illuminated.

You can only use the high-voltage outputs when the interlock is
asserted. If you try to assign a high-voltage output and turn the
source on when the interlock is not asserted, you see event
code 5074, “Output voltage limited by interlock.” Note that the
SOURCE swipe screen displays the value that was selected for the
voltage source, but the source value is limited to less than ±42 V.

An interlock circuit is provided on the rear panel of the instrument,
as shown in the following figure.

The interlock is intended for use through a normally open switch,
which may be installed on the lid of a test fixture, on the enclosure of
a semiconductor prober or device handler, or on the door or doors
of a test equipment rack. The switch must be closed to enable the
Model 2461 to produce voltages greater than ± 42 V.

When the interlock is asserted, the FORCE and GUARD terminals
should be considered hazardous voltages, even if they are
programmed to a non-hazardous voltage or current.

Potentially hazardous voltages of up to ±250 V may be present at
the Force HI, Sense HI, and Guard terminals when the interlock
circuit is closed. To prevent electrical shock, do not expose
these lines.

You can use the Keithley Instruments connector CS-1616-3, supplied
with the Model 2461, to make the interlock connection to the rear
panel. You must supply connection wire.

To ensure proper interlock operation, the external interlock switch
and connection wires must be less than 10 Ω when the switch is
closed.

The pin locations and connections are shown in the following figure.
The pins are:

 Pin 3: Earth and chassis ground
 Pin 2: Interlock
 Pin 1: +6 V DC out (current limited)

For the examples shown in this quick start guide, you do not need to
use an interlock. The Model 2461 functions on all current ranges and
up to ±42 volts without asserting the interlock.

Power on the instrument

The Model 2461 operates from a line voltage of 100 V to 240 V at a
frequency of 50 Hz or 60 Hz. The instrument senses the line voltage
automatically. Before connecting line power, make sure the operating
voltage in your area is compatible.

The power cord supplied with the Model 2461 contains a separate
protective earth (safety ground) wire for use with grounded outlets.
When proper connections are made, the instrument chassis is
connected to power-line ground through the ground wire in the
power cord. In addition, a redundant protective earth connection is
provided through a screw on the rear panel. This terminal should be
connected to a known protective earth. In the event of a failure, not
using a properly grounded protective earth and grounded outlet may
result in personal injury or death due to electric shock.
Do not replace detachable mains supply cords with inadequately
rated cords. Failure to use properly rated cords may result in
personal injury or death due to electric shock.

To connect line power:

1. Make sure the front panel power switch is in the off (O) position.

2. Connect the socket of the supplied power cord to the power
module on the rear panel.

3. Connect the plug of the power cord to a grounded AC outlet.

4. Turn on the instrument by pressing the front panel POWER
switch to the on (|) position. The instrument starts.

Overview of the front-panel options

The front panel of the Model 2461 allows you to set up most
instrument functions and features and perform sourcing and
measuring operations. The front panel includes:

 A touchscreen display that allows you to access instrument

settings and measurement readings.

 Keys that select menu options and start measurement operations.
 A navigation control that can be used to select screen options.
 An OUTPUT ON/OFF switch that turns the source output on

or off.

 Banana jack connections for FORCE HI and LO, SENSE HI

and LO, and chassis ground.

 A TERMINALS switch that determines if the instrument uses

the front or rear panel connections for sourcing and measuring.

Touchscreen display overview

You can use the touchscreen display to set up the instrument and
tests. You use the keys and touch capabilities to make selections.

To use the touchscreen, select options with your finger. You can also
use the navigation control to highlight an item, and then press the
control to select it.

The following text describes some of the most commonly used
screens. For more detail and descriptions of all the screens, see the
Model 2461 Reference Manual. For detail about an option, select it and
press the HELP key to read a brief description of the option.

Home screen overview

The Home screen is the first screen that opens when the instrument
is powered on. You can always return to the Home screen by
pressing the HOME key.

The top row on the Home screen displays the status and event
indicators. You can select these options to open dialog boxes that
provide additional information about the status or event.

The measure section of the Home screen displays the present
measurement. It also displays the measure functions and allows you
to select a measure range.

The bottom half of the display is the swipe screen area, which
contains the following additional screens:

 SOURCE swipe screen: Displays the source settings. When the

output is on, this displays either the programmed source value or
the actual source, depending on the setting of source readback.
On the source swipe screen, you can set the source range, source
value, and source limit. This is the default swipe screen.

 SETTINGS swipe screen: Allows you to turn features on and off,

such as the measurement filter, math functions, relative offset,
and NPLCs. You can touch the calculator or gear icons on the
right side of the swipe screen header bar to open the calculations
or source serrings screens.

 GRAPH swipe screen: Shows a graph of the readings in the

presently selected buffer. You can touch the graph icon on the
right side of the swipe screen header bar to open it to a
full screen view.

 STATISTICS swipe screen: Contains statistics based on the

readings in the active buffer.

 USER swipe screen: Displays information that you can define

through a remote interface.

Examples of the SETTINGS and GRAPH swipe screens are shown
below.

In the SETTINGS swipe screen shown here, the Auto Zero feature
is turned on. The other settings are turned off.

In the GRAPH swipe screen shown here, you can view the
measurements as they occur. To see a full-screen graph, touch the
graph icon on the right side of the swipe screen header bar to go to
the Graph screen. In the full-screen graph, you can also change the
data and scale of the information that is displayed on the graph.

ENTER and EXIT keys

The ENTER key selects a highlighted option. In most cases, it
opens a menu or dialog box that allows you to make settings for that
option.

The EXIT key returns to the previous menu or closes a dialog box.
For example, if you are in the MENU screen, pressing EXIT returns
you to the Home screen.

TRIGGER key

The action of the TRIGGER key depends on the trigger method
that is selected:

 If you set the instrument to continuously trigger, this displays a

dialog box that allows you to select another measurement
method.

 If you set the instrument to manually trigger, pressing the

TRIGGER key causes the instrument to make a measurement.

 If you defined a trigger model, pressing the TRIGGER key

initiates the trigger model.

Menu screen overview

When you press the MENU key on the front panel, the Menu screen
is displayed.

From this screen, you can select source, measure, graphing, trigger,
scripting, and system setup menus. These menus allow you to choose
options to set up your instrument to meet the needs of your
applications.

An example of the options that are available when you select the
Settings option under Measure is shown below.

Quick Setup options

When you press QUICKSET, the BASIC SOURCE/MEASURE
SETTINGS screen is displayed. From this menu, you can:

 Choose the source and measure functions.
 Use the Performance slider to select the best balance between

measurement resolution and measurement speed.

 Choose from a selection of Quick Setups that automatically make

the settings required for that setup, turn the output on, and begin
making measurements.

When you select a Quick Setup, the instrument turns the output
on. Carefully consider and configure the appropriate output-off
state, source, and limits before connecting the Model 2461 to a
device that can deliver energy, such as other voltage sources,
batteries, capacitors, or solar cells. Configure the settings that
are recommended for the instrument before making connections
to the device. Failure to consider the output-off state, source,
and limits may result in damage to the instrument or to the
device under test (DUT).

HELP

You can display help screens for the menu items and buttons. The
help screens give a brief description of the option that the menu or
button sets, and remote commands related to the setting. To display
the description, highlight the menu item or button and press the
HELP key. The graphic below shows an example of the help when
you are on the System Events tab of the event log.

FUNCTION

The FUNCTION key opens the FUNCTION selection dialog
box, which allows you to select the source, measure, and digitize
functions.

The instrument saves many of the commands with the source or
measure function that was active when you set them. For example, if
you set the measure function to current and you set a value for
NPLCs, the instrument saves the NPLC value for that measure
function. When you change the measure function to voltage, the
NPLC value changes to the value that was last set for the voltage
measure function.

.

Connections for testing

The following figures show the physical connections for the front
panel. Note that you must use either the front terminals or rear
terminals — you cannot mix connections. The rear-panel
connections are screw terminals. The front-panel connections are
safety banana jacks.

The example in this guide shows you how to make connections to
the front panel and short the connections.

For this example, you can make the connections with the insulated
banana cables that are supplied with the Model 2461, the Keithley
Instruments Model 8608 Safety Clip Lead Set.

1. Make sure the front-panel power switch is in the off (O)
position.

2. Connect the red lead to the FORCE HI connection.

3. Connect the black lead to the FORCE LO connection.

NEED

Verify measurement operation

The following steps provide a quick way to verify that the instrument
is operating correctly.

To verify measurement operation:

1. Turn the instrument on.

2. On the front panel, press the HOME key.

3. Press the FUNCTION key.

4. On the Measure tab, under Source Current and Measure, select
Voltage.

5. Select the button next to Source (at the bottom of the Home
screen). The Current Source Value dialog box is displayed.

6. Enter 10 mA.

7. Short the connections.

8. Press the OUTPUT ON/OFF switch to enable the output and
start making measurements.

9. When measurements are complete, press the OUTPUT
ON/OFF switch to disable the output.

The voltage measurements appear in the Measure Voltage area of the
Home screen.

To save the data to a USB flash drive:

1. Insert a USB flash drive into the front panel USB connector.

2. Press the MENU key.

3. Under Measure, select Reading Buffers.

4. Select defbuffer1. A menu is displayed.

5. Select Save To USB.

6. Enter the file name.

7. Select OK (on the screen).

8. A confirmation message is displayed. Select Yes.

The instrument saves the data to a .csv file on the flash drive.

To view the measurements on the front-panel graph:

1. Press the MENU key.

2. Under Views, select Graph.

You can swipe and use pinch and zoom to change the view of data
on the graph. You can also adjust the graph settings using the options
in the Data and Scale tabs.

FAQs

My data looks odd or is wrong. What should I do?

Verify the connections from the instrument to the test fixture. Also
check the connections from the DUT to the test fixture socket.

How do I change the command set?

In addition to the front-panel options, you can use a remote interface
to set up the instrument. You can choose one of the following
command sets:

 SCPI: An instrument-specific language built on the SCPI

standard.

 TSP: A programming language that you can use to send

individual commands or combine commands into scripts.

You cannot combine the command sets.

As delivered from Keithley Instruments, the Model 2461 is set to
work with the SCPI command set.

To set the command set using the front panel:

1. Press the MENU key.

2. Under System, select Settings.

3. Select the button next to Command Set.

4. Select the command set.

5. You are prompted to reboot.

Why did my settings change?

The instrument saves many of the commands with the source or
measure function that was active when you set them. For example,
assume you have the measure function set to current and set a value
for NPLCs. When you change the measure function to voltage, the
NPLC value changes to the value that was last set for the voltage
measure function. When you return to the current measure function,
the NPLC value returns to the value you set previously.

Next steps

For more information, refer to the 24GDI-950-01 Interactive
SourceMeter Product Information CD-ROM, which includes the
following documents:

 Model 2461 User Manual: Contains basic information about the

instrument, plus application-based examples that will help
familiarize you with the instrument.

 Model 2461 Reference Manual: Provides detailed information

about all features of the instrument.

Also see the Keithley Instruments website, www.keithley.com, for
support and additional information about the instrument.