Keithley 6517A, 6517 Service manual

Model 6517A

Electrometer

User’s Manual

Contains Operating and Programming Information

W ARRANTY

Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a period of 1 year
from date of shipment.

Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables, rechargeable
batteries, diskettes, and documentation.

During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.

To exercise this warranty, write or call your local Keithle y representative, or contact Keithle y headquarters in Cleveland, Ohio.
You will be given prompt assistance and return instructions. Send the product, transportation prepaid, to the indicated service
facility . Repairs will be made and the product returned, transportation prepaid. Repaired or replaced products are warranted for
the balance of the original warranty period, or at least 90 days.

LIMIT A TION OF W ARRANTY

This warranty does not apply to defects resulting from product modification without Keithley’s express written consent, or
misuse of any product or part. This warranty also does not apply to fuses, software, non-rechargeable batteries, damage from
battery leakage, or problems arising from normal wear or failure to follow instructions.

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY
IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE REMEDIES PRO­VIDED HEREIN ARE BUYER’S SOLE AND EXCLUSIVE REMEDIES.

NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT,
INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS
INSTRUMENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE
OF THE POSSIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, BUT ARE NOT LIM­ITED TO: COSTS OF REMOVAL AND INSTALLATION, LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY
PERSON, OR DAMAGE TO PROPERTY.

Keithley Instruments, Inc. • 28775 Aurora Road • Cleveland, OH 44139 • 440-248-0400 • Fax: [phone] • http://www.keithle y.com

BELGIUM: Keithley Instruments B.V.
CHINA: Keithley Instruments China
FRANCE: Keithley Instruments Sarl B.P. 60 • 3, allée des Garays • 91122 Palaiseau Cédex • 01 64 53 20 20 • Fax: [phone]
GERMANY: Keithley Instruments GmbH Landsberger Strasse 65 • D-82110 Germering • 089/84 93 07-40 • Fax: [phone]
GREAT BRITAIN: Keithley Instruments Ltd
INDIA: Keithley Instruments GmbH Flat 2B, WILOCRISSA • 14, Rest House Crescent • Bangalore 560 001 • 91-80-509-1320/21 • Fax: [phone]
ITALY: Keithley Instruments s.r.l. Viale S. Gimignano, 38 • 20146 Milano • 02/48 30 30 08 • Fax: [phone]
NETHERLANDS: Keithley Instruments B.V. Postbus 559 • 4200 AN Gorinchem • 0183-635333 • Fax: [phone]
SWITZERLAND: Keithley Instruments SA Kriesbachstrasse 4 • 8600 Dübendorf • 01-821 94 44 • Fax: [phone]
TAIWAN: Keithley Instruments Taiwan 1 Fl. 85 Po Ai Street • Hsinchu, Taiwan, R.O.C. • 886-3572-9077• Fax: [phone]

Bergensesteenweg 709 • B-1600 Sint-Pieters-Leeuw • 02/363 00 40 • Fax: [phone]
Y uan Chen Xin Building, Room 705 • 12 Yumin Road, Dew ai, Madian • Beijing 100029 • 8610-62022886 • Fax: [phone]

The Minster • 58 Portman Road • Reading, Berkshire RG30 1EA • 0118-9 57 56 66 • Fax: [phone]

10/99

Model 6517A Electrometer

User’s Manual

All references to the Model 6517 also apply to the Model 6517A.

©1996, Keithley Instruments, Inc.

All rights reserved.
Cleveland, Ohio, U.S.A.
Third Printing, July 2000

Document Number: 6517A-900-01 Rev. C

Manual Print History

The print history shown below lists the printing dates of all Revisions and Addenda created for this manual. The Revision
Level letter increases alphabetically as the manual undergoes subsequent updates. Addenda, which are released between Revi­sions, contain important change information that the user should incorporate immediately into the manual. Addenda are num­bered sequentially. When a new Revision is created, all Addenda associated with the previous Revision of the manual are
incorporated into the new Revision of the manual. Each new Revision includes a revised copy of this print history page.

Revision A (Document Number 6517A-900-01).............................................................................December 1996

Revision B (Document Number 6517A-900-01).............................................................................November 1999

Revision C (Document Number 6517A-900-01).......................................................................................July 2000

All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand and product names are trademarks or registered trademarks of their respective holders.

Safety Precautions

The following safety precautions should be observed before using
this product and any associated instrumentation. Although some in­struments and accessories would normally be used with non-haz­ardous voltages, there are situations where hazardous conditions
may be present.

This product is intended for use by qualified personnel who recog­nize shock hazards and are familiar with the safety precautions re­quired to avoid possible injury. Read the operating information
carefully before using the product.

The types of product users are:

Responsible body is the individual or group 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, for example, setting the line voltage or replac­ing consumable materials. Maintenance procedures are described in
the manual. The procedures explicitly state if the operator may per­form them. Otherwise, they should be performed only by service
personnel.

Service personnel are trained to work on live circuits, and perform

safe installations and repairs of products. Only properly trained ser­vice personnel may perform installation and service procedures.

Users of this product must be protected from electric shock at all
times. The responsible body must ensure that users are prevented
access and/or insulated from every connection point. In some cases,
connections must be exposed to potential human contact. Product
users in these circumstances must be trained to protect themselves
from the risk of electric shock. If the circuit is capable of operating
at or above 1000 volts,

exposed.

As described in the International Electrotechnical Commission
(IEC) Standard IEC 664, digital multimeter measuring circuits
(e.g., Keithley Models 175A, 199, 2000, 2001, 2002, and 2010) are
Installation Category II. All other instruments’ signal terminals are
Installation Category I and must not be connected to mains.

Do not connect switching cards directly to unlimited power circuits.
They are intended to be used with impedance limited sources.
NEVER connect switching cards directly to AC mains. When con­necting sources to switching cards, install protective devices to lim­it fault current and voltage to the card.

Before operating an instrument, make sure the line cord is connect­ed to a properly grounded power receptacle. Inspect the connecting
cables, test leads, and jumpers for possible wear, cracks, or breaks
before each use.

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.

no conductive part of the circuit may be

Exercise extreme caution when a shock hazard is present. Lethal
voltage may be present on cable connector jacks or test fixtures. The
American National Standards Institute (ANSI) states that a shock
hazard exists when voltage levels greater than 30V RMS, 42.4V
peak, or 60VDC are present.

pect that hazardous voltage is present in any un­known circuit before measuring.

A good safety practice is to ex-

Do not touch any object that could provide a current path to the
common side of the circuit under test or power line (earth) ground.
Always make measurements with dry hands while standing on a
dry, insulated surface capable of withstanding the voltage being
measured.

The instrument and accessories must be used in accordance with its
specifications and operating instructions or the safety of the equip­ment may be impaired.

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

When fuses are used in a product, replace with same type and rating
for continued protection against fire hazard.

Chassis connections must only be used as shield connections for
measuring circuits, NOT as safety earth ground connections.

If you are using a test fixture, keep the lid closed while power is ap­plied to the device under test. Safe operation requires the use of a
lid interlock.

If a screw is present, connect it to safety earth ground using the
wire recommended in the user documentation.

!

The symbol on an instrument indicates that the user should re­fer to the operating instructions located in the manual.

The symbol on an instrument shows that it can source or mea­sure 1000 volts or more, including the combined effect of normal
and common mode voltages. Use standard safety precautions to
avoid personal contact with these voltages.

The

WARNING heading in a manual explains dangers that might

result in personal injury or death. Alw ays read the associated infor ­mation very carefully before performing the indicated procedure.

CAUTION heading in a manual explains hazards that could

The
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, use a damp cloth or mild, water based
cleaner. Clean the exterior of the instrument only. Do not apply
cleaner directly to the instrument or allow liquids to enter or spill
on the instrument. Products that consist of a circuit board with no
case or chassis (e.g., data acquisition board for installation into a
computer) should never require cleaning if handled according to in­structions. If the board becomes contaminated and operation is af­fected, the board should be returned to the factory for proper
cleaning/servicing.

Rev.10/99

Table of Contents

1 General Information

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

1.2 Features............................................................................................................................................................... 1-1

1.3 Warranty information.......................................................................................................................................... 1-2

1.4 Manual addenda.................................................................................................................................................. 1-2

1.5 Safety symbols and terms ................................................................................................................................... 1-2

1.6 Specifications...................................................................................................................................................... 1-2

1.7 Inspection............................................................................................................................................................ 1-2

1.8 Options and accessories ...................................................................................................................................... 1-2

2 Front Panel Operation

2.1 Introduction......................................................................................................................................................... 2-1

2.2 Power-up............................................................................................................................................................. 2-2

2.2.1 Line power connections ...............................................................................................................................2-2

2.2.2 Line fuse replacement..................................................................................................................................2-2

2.2.3 Power-up sequence ......................................................................................................................................2-3

2.2.4 Power-on default conditions ........................................................................................................................2-3

2.2.5 Warm-up period...........................................................................................................................................2-4

2.2.6 IEEE-488 primary address...........................................................................................................................2-4

2.3 Display ................................................................................................................................................................ 2-4

2.3.1 Exponent mode (Engineering or Scientific).................................................................................................2-4

2.3.2 Information messages ..................................................................................................................................2-4

2.3.3 Status and error messages ............................................................................................................................2-5

2.3.4 Multiple displays..........................................................................................................................................2-7

2.3.5 Navigating menus ........................................................................................................................................2-8

2.4 Connections — electrometer, high-resistance meter, and V-source................................................................... 2-9

2.4.1 Electrometer input connector.......................................................................................................................2-9

2.4.2 High-resistance meter connections ............................................................................................................2-11

2.4.3 Voltage source output connections ............................................................................................................2-11

2.4.4 Low noise cables, shielding, and guarding ................................................................................................2-12

2.4.5 Floating circuits..........................................................................................................................................2-13

2.4.6 Test fixtures................................................................................................................................................2-15

2.5 Voltage measurements...................................................................................................................................... 2-18

2.5.1 Basic measurement procedure....................................................................................................................2-18

2.5.2 Volts configuration ....................................................................................................................................2-21

2.5.3 Voltage measurement considerations.........................................................................................................2-22

2.6 Current measurements....................................................................................................................................... 2-24

2.6.1 Basic measurement procedure................................................................................................................... 2-24

2.6.2 Amps configuration................................................................................................................................... 2-27

2.6.3 Current measurement considerations.........................................................................................................2-28

i

2.7 Resistance and resistivity measurements........................................................................................................... 2-32

2.7.1 Resistance measurements.......................................................................................................................... 2-33

2.7.2 Resistivity measurements.......................................................................................................................... 2-36

2.7.3 Ohms configuration....................................................................................................................................2-39

2.7.4 Multiple display..........................................................................................................................................2-42

2.7.5 Ohms measurement considerations............................................................................................................2-42

2.8 Charge measurements (Q)................................................................................................................................. 2-42

2.8.1 Basic measurement procedure................................................................................................................... 2-43

2.8.2 Coulombs configuration............................................................................................................................ 2-43

2.8.3 Charge measurement considerations..........................................................................................................2-45

2.9 Voltage source................................................................................................................................................... 2-46

2.9.1 Sourcing options........................................................................................................................................ 2-46

2.9.2 Setting voltage source value...................................................................................................................... 2-48

2.9.3 Voltage and current limit............................................................................................................................2-49

2.9.4 Interlock and test fixtures...........................................................................................................................2-50

2.9.5 Operate .......................................................................................................................................................2-50

2.10 Analog outputs................................................................................................................................................... 2-50

2.10.1 2V analog output ....................................................................................................................................... 2-51

2.10.2 Preamp out................................................................................................................................................. 2-52

2.11 Using external feedback .................................................................................................................................... 2-54

2.11.1 Electrometer input circuitry....................................................................................................................... 2-54

2.11.2 Shielded fixture construction..................................................................................................................... 2-54

2.11.3 External feedback procedure..................................................................................................................... 2-55

2.11.4 Non-standard coulombs ranges ................................................................................................................. 2-56

2.11.5 Logarithmic currents ..................................................................................................................................2-56

2.11.6 Non-decade current gains...........................................................................................................................2-57

2.12 Range and resolution......................................................................................................................................... 2-57

2.12.1 Measurement range ....................................................................................................................................2-57

2.12.2 Display resolution.......................................................................................................................................2-57

2.13 Zero check, relative, and zero correct ................................................................................................................2-58

2.13.1 Zero check..................................................................................................................................................2-58

2.13.2 Relative (REL)............................................................................................................................................2-59

2.13.3 Zero correct ................................................................................................................................................2-60

2.14 Test sequences....................................................................................................................................................2-60

2.14.1 Test descriptions.........................................................................................................................................2-60

2.14.2 Configure Test Sequence............................................................................................................................2-68

2.14.3 Running the selected test............................................................................................................................2-70

2.15 Triggers...............................................................................................................................................................2-71

2.15.1 Trigger model.............................................................................................................................................2-73

2.15.2 Basic trigger configuration.........................................................................................................................2-76

2.15.3 Advanced trigger configuration..................................................................................................................2-77

2.15.4 External triggering......................................................................................................................................2-81

2.15.5 Trigger Link................................................................................................................................................2-83

2.16 Buffer..................................................................................................................................................................2-94

2.16.1 Configuring data storage ............................................................................................................................2-96

2.16.2 Storing and recalling readings....................................................................................................................2-98

2.16.3 Buffer multiple displays...........................................................................................................................2-100

2.17 Filters................................................................................................................................................................2-100

2.17.1 Digital filters.............................................................................................................................................2-101

2.17.2 Median filter.............................................................................................................................................2-101

2.17.3 Configuring the filters ..............................................................................................................................2-103

2.18 Math..................................................................................................................................................................2-105

2.18.1 Polynomial................................................................................................................................................2-105

2.18.2 Percent......................................................................................................................................................2-105

ii

2.18.3 Percent deviation......................................................................................................................................2-105

2.18.4 Deviation..................................................................................................................................................2-105

2.18.5 Ratio.........................................................................................................................................................2-106

2.18.6 Logarithmic..............................................................................................................................................2-106

2.18.7 Selecting and configuring math ...............................................................................................................2-106

2.18.8 Calculate multiple display........................................................................................................................2-107

2.19 Menu ................................................................................................................................................................2-107

2.19.1 SAVESETUP...........................................................................................................................................2-110

2.19.2 COMMUNICATION...............................................................................................................................2-116

2.19.3 CAL..........................................................................................................................................................2-117

2.19.4 TEST........................................................................................................................................................2-118

2.19.5 LIMITS ....................................................................................................................................................2-118

2.19.6 STATUS-MSG.........................................................................................................................................2-120

2.19.7 GENERAL...............................................................................................................................................2-120

2.20 Scanning...........................................................................................................................................................2-125

2.20.1 Internal scanning......................................................................................................................................2-125

2.20.2 External scanning.....................................................................................................................................2-125

2.21 Other measurement considerations..................................................................................................................2-126

2.21.1 Ground loops............................................................................................................................................2-126

2.21.2 Triboelectric effects .................................................................................................................................2-127

2.21.3 Piezoelectric and stored charge effects....................................................................................................2-127

2.21.4 Electrochemical effects............................................................................................................................2-127

2.21.5 Humidity ..................................................................................................................................................2-127

2.21.6 Light.........................................................................................................................................................2-127

2.21.7 Electrostatic interference..........................................................................................................................2-127

2.21.8 Magnetic fields.........................................................................................................................................2-128

2.21.9 Electromagnetic interference (EMI) ........................................................................................................2-128

2.22 Relative humidity and external temperature readings......................................................................................2-128

3 IEEE-488 Reference

3.1 Introduction......................................................................................................................................................... 3-1

3.2 Connections......................................................................................................................................................... 3-2

3.2.1 IEEE-488 bus connections...........................................................................................................................3-2

3.2.2 RS-232 serial interface connections.............................................................................................................3-3

3.3 GPIB primary address selection.......................................................................................................................... 3-3

3.4 GPIB programming language selection.............................................................................................................. 3-4

3.5 QuickBASIC 4.5 programming .......................................................................................................................... 3-4

3.6 General bus commands....................................................................................................................................... 3-5

3.6.1 REN (remote enable) ...................................................................................................................................3-5

3.6.2 IFC (interface clear).....................................................................................................................................3-5

3.6.3 LLO (local lockout) .....................................................................................................................................3-6

3.6.4 GTL (go to local) .........................................................................................................................................3-6

3.6.5 DCL (device clear).......................................................................................................................................3-6

3.6.6 SDC (selective device clear)........................................................................................................................3-6

3.6.7 GET (group execute trigger)........................................................................................................................3-6

3.6.8 SPE, SPD (serial polling).............................................................................................................................3-6

3.7 Front panel aspects of IEEE-488 operation ........................................................................................................ 3-7

3.7.1 Error and status messages ............................................................................................................................3-7

3.7.2 IEEE-488 status indicators...........................................................................................................................3-7

3.7.3 LOCAL key..................................................................................................................................................3-7

3.8 Status structure.................................................................................................................................................... 3-7

3.8.1 Condition registers.................................................................................................................................... 3-14

iii

3.8.2 Transition filters ........................................................................................................................................ 3-14

3.8.3 Event registers ............................................................................................................................................3-15

3.8.4 Enable registers ..........................................................................................................................................3-15

3.8.5 Queues........................................................................................................................................................3-15

3.8.6 Status byte and service request (SRQ) .......................................................................................................3-16

3.9 Trigger Model (IEEE-488 operation)................................................................................................................ 3-18

3.10 Programming syntax...........................................................................................................................................3-21

3.11 Common commands...........................................................................................................................................3-27

3.11.1 *CLS — clear status...................................................................................................................................3-27

3.11.2 *ESE <NRf> — event enable ....................................................................................................................3-28

ESE? — event enable query

3.11.3 *ESR? — event status register query.........................................................................................................3-29

3.11.4 *IDN? — identification query....................................................................................................................3-30

3.11.5 *OPC — operation complete......................................................................................................................3-31

3.11.6 *OPC? — operation complete query..........................................................................................................3-32

3.11.7 *OPT? — option identification query........................................................................................................3-33

3.11.8 *RCL — recall ...........................................................................................................................................3-33

3.11.9 *RST — reset the Model 6517A................................................................................................................3-33

3.11.10 *SAV — save the current setup in memory...............................................................................................3-33

3.11.11 *SRE <NRf> — service request enable.....................................................................................................3-34

SRE? — service request enable query

3.11.12 *STB? — status byte query........................................................................................................................3-35

3.11.13 *TRG — trigger .........................................................................................................................................3-36

3.11.14 *TST? — self-test query ............................................................................................................................3-36

3.11.15 *WAI — wait-to-continue..........................................................................................................................3-36

3.12 Signal oriented measurement commands...........................................................................................................3-38

3.13 Calculate subsystems..........................................................................................................................................3-62

3.13.1 :CALCulate[1]............................................................................................................................................3-62

3.13.2 :CALCulate2...............................................................................................................................................3-65

3.13.3 :CALCulate3...............................................................................................................................................3-67

3.14 :CALibration subsystem.....................................................................................................................................3-71

3.15 :DISPlay subsystem............................................................................................................................................3-72

3.16 :FORMat subsystem...........................................................................................................................................3-75

3.17 Output Subsystems.............................................................................................................................................3-80

3.18 :ROUTe subsystem.............................................................................................................................................3-81

3.18.1 :CLOSe <list>.............................................................................................................................................3-81

3.18.2 :OPEN <list>..............................................................................................................................................3-81

3.18.3 :OPEN:ALL................................................................................................................................................3-82

3.18.4 :SCAN commands......................................................................................................................................3-82

3.19 :SENSe1 subsystem............................................................................................................................................3-85

3.19.1 [:SENSe[1]] subsystem ..............................................................................................................................3-85

3.19.2 :FUNCtion <name>....................................................................................................................................3-85

3.19.3 :DATA commands......................................................................................................................................3-85

3.19.4 :APERture <n>...........................................................................................................................................3-87

3.19.5 :NPLCycles <n>.........................................................................................................................................3-89

3.19.6 RANGe commands.....................................................................................................................................3-90

3.19.7 :REFerence <n>..........................................................................................................................................3-95

3.19.8 :IREFerence <b> ........................................................................................................................................3-97

3.19.9 :DIGits <n>.................................................................................................................................................3-97

3.19.10 :AVERage commands................................................................................................................................3-98

3.19.11 :MEDian Commands................................................................................................................................3-100

3.19.12 :DAMPing <b>.........................................................................................................................................3-101

3.19.13 :GUARd <b>............................................................................................................................................3-101

3.19.14 :ADIScharge Commands..........................................................................................................................3-102

iv

3.19.15 :XFEedback <b>......................................................................................................................................3-102

3.19.16 :VSControl <name>.................................................................................................................................3-102

3.19.17 :MSELect <name>...................................................................................................................................3-103

3.19.18 :RESistivity commands............................................................................................................................3-103

3.20 :SOURce subsystem.........................................................................................................................................3-106

3.20.1 Digital Output Commands .......................................................................................................................3-106

3.20.2 V-Source Configuration Commands:.......................................................................................................3-106

3.21 :STATus subsystem .........................................................................................................................................3-109

3.21.1 [:EVENt]? ................................................................................................................................................3-109

3.21.2 :ENABle <NRf> ......................................................................................................................................3-114

3.21.3 :PTRansition <NRf>................................................................................................................................3-117

3.21.4 :NTRansition <NRf>................................................................................................................................3-124

3.21.5 :CONDition?............................................................................................................................................3-126

3.21.6 :PRESet....................................................................................................................................................3-126

3.21.7 :QUEue commands ..................................................................................................................................3-127

3.22 :SYSTem subsystem ........................................................................................................................................3-129

3.22.1 :PRESet....................................................................................................................................................3-129

3.22.2 :POSetup <name>....................................................................................................................................3-129

3.22.3 :VERSion? ...............................................................................................................................................3-129

3.22.4 :ERRor?....................................................................................................................................................3-129

3.22.5 :LSYNc:STATe <b>................................................................................................................................3-130

3.22.6 :KEY <NRf>............................................................................................................................................3-130

3.22.7 :CLEar......................................................................................................................................................3-131

3.22.8 :DATE <yr>, <mo>, <day>.....................................................................................................................3-132

3.22.9 :TIME <hr>, <min>, <sec>......................................................................................................................3-132

3.22.10 :TSTamp commands ................................................................................................................................3-132

3.22.11 :RNUMber:RESet....................................................................................................................................3-133

3.22.12 Zero check and zero correct commands...................................................................................................3-133

3.22.13 A/D Controls............................................................................................................................................3-134

3.22.14 RS-232 Interface Commands...................................................................................................................3-135

3.22.15 Basic Trigger Commands.........................................................................................................................3-135

3.22.16 :INTerlock?..............................................................................................................................................3-137

3.23 :TRACe subsystem ..........................................................................................................................................3-137

3.23.1 :CLEar......................................................................................................................................................3-137

3.23.2 :FREE?.....................................................................................................................................................3-137

3.23.3 :POINts <n>.............................................................................................................................................3-138

3.23.4 :FEED Commands ...................................................................................................................................3-139

3.23.5 :DATA?....................................................................................................................................................3-141

3.23.6 :TSTamp:FORMat <name>.....................................................................................................................3-141

3.23.7 :ELEMents <item list>.............................................................................................................................3-141

3.24 Trigger subsystem............................................................................................................................................3-142

3.24.1 :INITiate commands ................................................................................................................................3-142

3.24.2 :ABORt ....................................................................................................................................................3-142

3.24.3 :IMMediate...............................................................................................................................................3-143

3.24.4 :COUNt <n>.............................................................................................................................................3-143

3.24.5 :DELay <n>..............................................................................................................................................3-143

3.24.6 :SOURce <name>....................................................................................................................................3-144

3.24.7 :TIMer <n>...............................................................................................................................................3-144

3.24.8 :SIGNal ....................................................................................................................................................3-145

3.24.9 TCONfigure commands...........................................................................................................................3-145

3.24.10 RTCLock commands ...............................................................................................................................3-147

3.25 :TSEQuence Subsystem...................................................................................................................................3-148

3.25.1 General Test Sequence Commands..........................................................................................................3-148

3.25.2 :STARt <NRf>.........................................................................................................................................3-149

3.25.3 :STOP <NRf> ..........................................................................................................................................3-150

v

3.25.4 :STEP <NRf> ...........................................................................................................................................3-150

3.25.5 :MDELay <NRf> .....................................................................................................................................3-150

3.25.6 :SVOLtage <NRf> ...................................................................................................................................3-151

3.25.7 :STIMe <NRf> .........................................................................................................................................3-151

3.25.8 :DTIMe <NRf>.........................................................................................................................................3-152

3.25.9 :PDTIMe <NRf> ......................................................................................................................................3-152

3.25.10 :MVOLtage <NRf>..................................................................................................................................3-152

3.25.11 :MTIMe <NRf>........................................................................................................................................3-153

3.25.12 :HLEVel <NRf>.......................................................................................................................................3-153

3.25.13 :HTIMe <NRf>.........................................................................................................................................3-153

3.25.14 :LLEVel <NRf> .......................................................................................................................................3-153

3.25.15 :LTIMe <NRf>.........................................................................................................................................3-154

3.25.16 :COUNt <NRf>........................................................................................................................................3-154

3.25.17 :OFSVoltage <NRf>.................................................................................................................................3-154

3.25.18 :ALTVoltage <NRf>................................................................................................................................3-154

3.25.19 :READings <NRf>...................................................................................................................................3-154

3.25.20 :DISCard <NRf> ......................................................................................................................................3-155

3.25.21 :SPOints <NRf> .......................................................................................................................................3-155

3.25.22 :SPINterval <NRf>...................................................................................................................................3-155

3.25.23 Test sequence programming example ......................................................................................................3-155

3.26 UNIT Subsystem..............................................................................................................................................3-156

3.27 RS-232 Serial Interface ....................................................................................................................................3-157

3.27.1 RS-232 Interface Configuration ...............................................................................................................3-157

3.27.2 RS-232 Operating Considerations............................................................................................................3-157

3.27.3 RS-232 Interface Error Messages.............................................................................................................3-158

3.27.4 Downloading commands using ProComm...............................................................................................3-158

3.28 DDC programming language ...........................................................................................................................3-158

A Specifications
B Interface Functions Codes
C ASCII Character Codes and IEEE-488 Multiline Interface Command Messages
D IEEE-488 Bus Overview
E IEEE-488 Conformance Information
F SCPI Conformance Information
G Device Dependent Command Summary

vi

List of Illustrations

2 Calibration

Figure 2-1 Line voltage switch..................................................................................................................................... 2-2

Figure 2-A Input signal...................................................................................................................................................2-5

Figure 2-B Measurement on 20nA range .......................................................................................................................2-5

Figure 2-2 Bar graph (zero-at-left) multiple display..................................................................................................... 2-8

Figure 2-3 Zero-centered bar graph multiple display................................................................................................... 2-8

Figure 2-4 Maximum and minimum multiple display.................................................................................................. 2-8

Figure 2-5 Input connector configurations ................................................................................................................. 2-10

Figure 2-6 Maximum input levels .............................................................................................................................. 2-10

Figure 2-7 Capacitor test circuit without protection................................................................................................... 2-10

Figure 2-8 Capacitor test circuit with protection........................................................................................................ 2-10

Figure 2-9 Force voltage measure current...................................................................................................................2-11

Figure 2-10 V-source output..........................................................................................................................................2-11

Figure 2-11 Noise shield................................................................................................................................................2-12

Figure 2-12 Guard shield...............................................................................................................................................2-13

Figure 2-13 Safety shield...............................................................................................................................................2-13

Figure 2-14 Floating measurements ..............................................................................................................................2-14

Figure 2-15 Floating V-source.......................................................................................................................................2-14

Figure 2-16 Test fixture to source voltage, measure current (resistance measurements)..............................................2-16

Figure 2-17 Multi-purpose test fixture...........................................................................................................................2-17

Figure 2-18 Interlock connections.................................................................................................................................2-17

Figure 2-19 Hard-wired interlock..................................................................................................................................2-18

Figure 2-20 Typical connections for unguarded voltage measurements.......................................................................2-19

Figure 2-21 Typical connections for guarded voltage measurements...........................................................................2-20

Figure 2-22 Meter loading.............................................................................................................................................2-23

Figure 2-23 Unguarded voltage measurements.............................................................................................................2-23

Figure 2-24 Guarded voltage measurements.................................................................................................................2-24

Figure 2-25 Typical connections for current measurements..........................................................................................2-25

Figure 2-26 Connections for guarded, floating current measurements..........................................................................2-26

Figure 2-27 Voltage burden considerations...................................................................................................................2-29

Figure 2-28 Source resistance and capacitance .............................................................................................................2-30

Figure 2-29 High impedance current measurements.....................................................................................................2-31

Figure 2-30 Floating current measurements..................................................................................................................2-31

Figure 2-31 Typical connections for resistance measurements.....................................................................................2-34

Figure 2-32 Connections for resistance measurements using Model 8002A test fixture..............................................2-35

Figure 2-33 Surface resistivity measurement technique................................................................................................2-36

Figure 2-34 Circular electrode dimensions....................................................................................................................2-37

Figure 2-35 Volume resistivity measurement technique...............................................................................................2-37

Figure 2-36 Connections for measurements using Model 8009 test fixture..................................................................2-39

Figure 2-37 Typical connections for charge measurements..........................................................................................2-44

Figure 2-38 V-source (independent configuration).......................................................................................................2-47

vii

Figure 2-39 V-source (FVMI configuration).................................................................................................................2-48

Figure 2-40 Typical 2V analog output connections.......................................................................................................2-51

Figure 2-41 Typical preamp out connections.................................................................................................................2-53

Figure 2-42 Electrometer input circuitry (external feedback mode)..............................................................................2-54

Figure 2-43 Shielded fixture construction......................................................................................................................2-55

Figure 2-44 “Transdiode” logarithmic current configuration........................................................................................2-57

Figure 2-45 Non-decade current gains...........................................................................................................................2-58

Figure 2-46 Equivalent input impedance with zero check enabled ...............................................................................2-59

Figure 2-47 Connections; diode leakage current test.....................................................................................................2-61

Figure 2-48 Default measurement points; diode leakage current test............................................................................2-61

Figure 2-49 Connections; capacitor leakage test............................................................................................................2-62

Figure 2-50 Connections; cable insulation resistance test .............................................................................................2-63

Figure 2-51 Test circuit; resistor voltage coefficient test...............................................................................................2-64

Figure 2-52 Alternating polarity resistance/resistivity test............................................................................................2-65

Figure 2-53 Connections; surface insulation resistance test ..........................................................................................2-66

Figure 2-54 Default measurement points; square wave sweep test ...............................................................................2-67

Figure 2-55 Default measurement points; staircase sweep test......................................................................................2-67

Figure 2-56 Basic trigger model.....................................................................................................................................2-73

Figure 2-57 Advanced trigger model.............................................................................................................................2-74

Figure 2-58 External triggering connectors ...................................................................................................................2-81

Figure 2-59 External triggering and asynchronous trigger link input pulse specifications ...........................................2-81

Figure 2-60 Meter complete and asynchronous trigger link output pulse specifications...............................................2-82

Figure 2-61 DUT test system.........................................................................................................................................2-82

Figure 2-62 External trigger connections.......................................................................................................................2-82

Figure 2-63 Trigger link connector................................................................................................................................2-84

Figure 2-64 DUT test system.........................................................................................................................................2-85

Figure 2-65 Trigger Link connections (asynchronous example #1)..............................................................................2-85

Figure 2-66 Operation model for asynchronous trigger link example #1......................................................................2-87

Figure 2-67 Connections using Trigger Link adapter....................................................................................................2-88

Figure 2-68 DUT test system (asynchronous example #2)............................................................................................2-88

Figure 2-69 Trigger Link connections (asynchronous example #2)..............................................................................2-89

Figure 2-70 Operation model for asynchronous Trigger Link example #2 ...................................................................2-90

Figure 2-71 Semi-synchronous Trigger Link specifications..........................................................................................2-91

Figure 2-72 Typical semi-synchronous mode connections............................................................................................2-91

Figure 2-73 Trigger Link connections (semi-synchronous example)............................................................................2-92

Figure 2-74 Operation model for semi-synchronous Trigger Link example.................................................................2-93

Figure 2-75 Digital filter; averaging and advanced filter types...................................................................................2-102

Figure 2-76 Digital filter; moving and repeating filter modes.....................................................................................2-103

Figure 2-77 Limits bar graph example.........................................................................................................................2-119

Figure 2-78 Using limit test to sort 100k Ω resistors....................................................................................................2-120

Figure 2-79 Digital I/O port.........................................................................................................................................2-120

Figure 2-80 Digital I/O port simplified schematic.......................................................................................................2-121

Figure 2-81 Sample externally powered relays............................................................................................................2-122

Figure 2-82 Line cycle synchronization.......................................................................................................................2-123

Figure 2-83 Multiple ground points create a ground loop ...........................................................................................2-126

Figure 2-84 Eliminating ground loops.........................................................................................................................2-127

viii

3 IEEE-488 Reference

Figure 3-1 IEEE-488 connector.................................................................................................................................... 3-2

Figure 3-2 IEEE-488 connections..................................................................................................................................3-2

Figure 3-3 IEEE-488 connector location.......................................................................................................................3-2

Figure 3-4 RS-232 interface connector..........................................................................................................................3-3

Figure 3-5 Model 6517A status register structure .........................................................................................................3-8

Figure 3-6 Standard event status....................................................................................................................................3-9

Figure 3-7 Operation event status..................................................................................................................................3-9

Figure 3-8 Arm event status.........................................................................................................................................3-10

Figure 3-9 Sequence event status.................................................................................................................................3-11

Figure 3-10 Trigger event status....................................................................................................................................3-12

Figure 3-11 Measurement event status..........................................................................................................................3-13

Figure 3-12 Questionable event status...........................................................................................................................3-14

Figure 3-13 Status byte and service request (SRQ).......................................................................................................3-16

Figure 3-14 Trigger Model (IEEE-488 bus operation)..................................................................................................3-19

Figure 3-15 Standard Event Enable Register.................................................................................................................3-29

Figure 3-16 Standard Event Status Register..................................................................................................................3-29

Figure 3-17 Service Request Enable Register ...............................................................................................................3-34

Figure 3-18 Status Byte Register...................................................................................................................................3-35

Figure 3-19 ASCII data format......................................................................................................................................3-76

Figure 3-20 IEEE754 single precision data format (32 data bits) .................................................................................3-76

Figure 3-21 IEEE754 double precision data format (64 data bits)................................................................................3-77

Figure 3-22 Measurement Event Register...................................................................................................................3-110

Figure 3-23 Questionable Event Register....................................................................................................................3-111

Figure 3-24 Operation Event Register.........................................................................................................................3-112

Figure 3-25 Trigger Event Register.............................................................................................................................3-113

Figure 3-26 Arm Event Register..................................................................................................................................3-113

Figure 3-27 Sequence Event Register..........................................................................................................................3-114

Figure 3-28 Measurement Event Enable Register.......................................................................................................3-115

Figure 3-29 Questionable Event Enable Register........................................................................................................3-115

Figure 3-30 Operation Event Enable Register.............................................................................................................3-116

Figure 3-31 Trigger Event Enable Register.................................................................................................................3-116

Figure 3-32 Arm Event Enable Register......................................................................................................................3-116

Figure 3-33 Sequence Event Enable Register..............................................................................................................3-117

Figure 3-34 Measurement Transition Filter.................................................................................................................3-118

Figure 3-35 Questionable Transition Filter .................................................................................................................3-119

Figure 3-36 Operation Transition Filter.......................................................................................................................3-120

Figure 3-37 Trigger Transition Filter...........................................................................................................................3-121

Figure 3-38 Arm Transition Filter...............................................................................................................................3-122

Figure 3-39 Sequence Transition Filter.......................................................................................................................3-123

Figure 3-40 Key-press codes .......................................................................................................................................3-131

D IEEE-488 Bus Overview

Figure D-1 IEEE-488 bus configuration....................................................................................................................... D-2

Figure D-2 IEEE-488 handshake sequence...................................................................................................................D-3

Figure D-3 Command codes..........................................................................................................................................D-6

ix

List of Tables

2 Front Panel Operation

Table 2-1 Line fuse selection ...................................................................................................................................... 2-2

Table 2-2 Data checked on power-up.......................................................................................................................... 2-3

Table 2-3 Power-up error messages ............................................................................................................................ 2-3

Table 2-4 Typical display exponent values................................................................................................................. 2-4

Table 2-5 Status and error messages ........................................................................................................................... 2-6

Table 2-6 Multiple (Next) displays by function.......................................................................................................... 2-7

Table 2-7 EXIT key actions ........................................................................................................................................ 2-9

Table 2-8 CONFIGURE VOLTS menu structure..................................................................................................... 2-21

Table 2-9 CONFIGURE AMPS menu structure....................................................................................................... 2-28

Table 2-10 Minimum recommended source resistance values.................................................................................... 2-29

Table 2-11 Ohms reading ranges and AUTO V-Source.............................................................................................. 2-33

Table 2-12 CONFIGURE OHMS menu structure ...................................................................................................... 2-40

Table 2-13 CONFIGURE COULOMBS menu structure............................................................................................ 2-45

Table 2-14 V-Source ranges........................................................................................................................................ 2-46

Table 2-15 CONFIGURE V-Source menu structure................................................................................................... 2-46

Table 2-16 Typical 2V analog output values .............................................................................................................. 2-51

Table 2-17 Full-range PREAMP OUT values..............................................................................................................2-52

Table 2-18 Integration times set-by-resolution (all functions).....................................................................................2-58

Table 2-19 Auto resolution (all functions) ...................................................................................................................2-58

Table 2-20 CONFIGURE SEQUENCE menu structure ..............................................................................................2-69

Table 2-21 CONFIGURE TRIGGER menu structure..................................................................................................2-71

Table 2-22 Maximum buffer readings..........................................................................................................................2-95

Table 2-23 CONFIGURE DATA STORE menu structure ..........................................................................................2-96

Table 2-24 Fill-and-stop sequence ...............................................................................................................................2-99

Table 2-25 Continuous sequence..................................................................................................................................2-99

Table 2-26 Pretrigger sequence ....................................................................................................................................2-99

Table 2-27 CONFIGURE FILTER menu structure ...................................................................................................2-104

Table 2-28 CONFIGURE MATH menu structure .....................................................................................................2-106

Table 2-29 MAIN MENU STRUCTURE..................................................................................................................2-108

Table 2-30 Factory default conditions........................................................................................................................2-111

3 IEEE-488 Reference

Table 3-1 General bus commands and associated statements..................................................................................... 3-5

Table 3-2 IEEE-488.2 common commands and queries........................................................................................... 3-27

Table 3-3 Signal oriented measurement command summary ................................................................................... 3-38

Table 3-4 CALCulate command summary................................................................................................................ 3-42

Table 3-5 CALibration command summary.............................................................................................................. 3-44

Table 3-6 DISPlay command summary .................................................................................................................... 3-44

xi

Table 3-7 FORMat command summary.................................................................................................................... 3-45

Table 3-8 OUTput command summary..................................................................................................................... 3-45

Table 3-9 ROUTe command summary.......................................................................................................................3-46

Table 3-10 SENSe command summary........................................................................................................................3-46

Table 3-11 SOURce command summary .....................................................................................................................3-52

Table 3-12 STATus command summary......................................................................................................................3-53

Table 3-13 SYSTem command summary.....................................................................................................................3-55

Table 3-14 TRACe command summary.......................................................................................................................3-56

Table 3-15 Trigger command summary .......................................................................................................................3-57

Table 3-16 :TSEQuence command summary ...............................................................................................................3-58

Table 3-17 :UNIT command summary.........................................................................................................................3-60

B Interface Function Codes

Table B-1 Model 6517A interface function codes ...................................................................................................... B-1

D IEEE-488 Bus Overview

Table D-1 IEEE-488 bus command summary............................................................................................................. D-4

Table D-2 Hexadecimal and decimal command codes.................................................................................................D-7

Table D-3 Typical addressed command sequence........................................................................................................D-7

Table D-4 Typical common command sequence .........................................................................................................D-7

Table D-5 IEEE command groups................................................................................................................................D-8

E IEEE-488 Conformance Information

Table E-1 IEEE-488 documentation requirements ..................................................................................................... E-1

Table E-2 Coupled commands .....................................................................................................................................E-3

xii

1

General Information

1.1 Introduction

This section contains general information about the Model
6517A Electrometer/High Resistance Meter. It is arranged in
the following manner:

1.2 Features

1.3 Warranty information

1.4 Manual addenda

1.5 Safety symbols and terms

1.6 Specifications

1.7 Inspection

1.8 Options and accessories

1.2 Features

Some important Model 6517A features include:

• Full range of functions — Exceptional sensitivity and
accuracy for voltage, current, charge, and V/I resistance
and resistivity (surface and volume) measure­ments.With the Models 6517-RH and 6517-TP, relative
humidity and external temperature can be measured.

• Voltage source — The internal 1000V V-Source can be
configured with the ammeter to make V/I resistance/re­sistivity measurements, and to force voltage, measure
current.

• T wo-line display — Readings and front panel messages
are provided on the top line (primary) 20-character, and
bottom line (secondary) 32-character alphanumeric dis­play. The multiple display pro vides supplemental infor-

mation about the reading, such as min/max readings,
bar graphs for the reading, and time and date.

• Reading and setup storage — Readings and setup data
can be stored and recalled from memory. Over 15,000
readings can be stored in the buffer , and up to 10 instru­ment setups can be stored in memory.

• T est sequences — Built-in tests for the follo wing appli­cations: device characterization, resistivity, high resis­tance/resistivity (alternating polarity method), surface
insulation resistance, and voltage sweeps.

• GPIB interface — Accommodates two separate lan­guages for IEEE-488 operation. The SCPI language
conforms to the IEEE-488.2 and SCPI standards. The
617 emulation mode (DDC language) allows the instru­ment to be controlled using device-dependent com­mand programming.

• RS-232 interface — The instrument can instead be con­trolled over this serial interface using SCPI commands.

• T alk-only mode — From the front panel, you can set the
instrument to send readings to a printer. Talk-only is
available over both the GPIB and RS-232 interfaces.

• Scanning — The Model 6517A has an option slot that
will accommodate an optional scanner card (Models
6521 and 6522). The instrument can also be configured
to operate with an external switching system (i.e., Mod­el 7001 or 7002) to scan external channels.

• Trigger link — This is a new trigger concept that pro­vides more versatile and precise external triggering. It
is in addition to the standard Trigger In/Meter Complete
Out BNC external triggering techniques.

• Digital calibration — The instrument may be digitally
calibrated from either the front panel, or over the RS­232 interface or GPIB bus (SCPI language).

1-1

General Information

1.3 W arranty information

Warranty information is located on the inside front cover of
this instruction manual. Should your Model 6517A require
warranty service, contact the Keithley representative or au­thorized repair facility in your area for further information.
When returning the instrument for repair, be sure to fill out
and include the service form at the back of this manual to
provide the repair facility with the necessary information.

1.4 Manual addenda

Any improvements or changes concerning the instrument or
manual will be explained in an addendum included with the
manual. Be sure to note these changes and incorporate them
into the manual.

1.5 Safety symbols and terms

The following symbols and terms may be found on an instru­ment or used in this manual.

!

The symbol on an instrument indicates that the user
should refer to the operating instructions located in the manual.

The symbol on an instrument shows that high voltage
may be present on the terminal(s). Use standard safety pre­cautions to avoid personal contact with these voltages.

The symbol indicates that the test fixture (i.e. Model

8009) must be connected to a safety earth ground using #18
AWG wire or larger.

The WARNING heading used in this manual explains dan­gers that might result in personal injury or death. Always
read the associated information very carefully before per­forming the indicated procedure.

The CAUTION heading used in this manual explains haz­ards that could damage the instrument. Such damage may in­validate the warranty.

1.6 Specifications

1.7 Inspection

The Model 6517A was carefully inspected, both electrically
and mechanically before shipment. After unpacking all items
from the shipping carton, check for any obvious signs of
physical damage that may have occurred during transit.
(Note: There may be a protective film over the display lens,
which can be removed.) Report any damage to the shipping
agent immediately. Save the original packing carton for pos­sible future reshipment.

If an additional manual is required; order the appropriate
manual package:

• Model 6517A User’s Manual — Keithley P/N
6517A-900-00

• Model 6517 Getting Started Manual — Keithley
P/N 6517-903-00

• Model 6517 Service Manual — Keithley P/N
6517-905-00

1.8 Options and accessories

The following options and accessories are available from
Keithley for use with the Model 6517A:

Model 237-ALG-2 Triax Cable: This is a 2-meter (6.6 ft.)

low noise triax cable terminated with a 3-slot male triax con­nector on one end and 3 alligator clips on the other.

Model 237-BNC-TRX Adapter: This is a male BNC to 3-

lug female triax adapter (guard disconnected). It is used to
terminate a triax cable with a BNC plug. Suitable for use with
the Model 6517A V-Source in high voltage applications.

Model 237-TRX-T Adapter: This is a 3-slot male to dual 3-

lug female triax tee adapter for use with 7078-TRX triax ca­bles. Suitable for use with the Model 6517A V-Source in
high voltage applications.

Model 7078-TRX-BNC Adapter: This is a 3-slot male triax

to female BNC adapter. This adapter lets you connect a BNC
cable to the triax input of the Model 6517A. Suitable for use
with the Model 6517A in high voltage applications.

Model 237-TRX-TBC Connector: This is a 3-lug female

triax bulkhead connector with cap for assembly of custom
panels and interface connections. Suitable for use with the
Model 6517A V-Source in high voltage applications.

Full Model 6517A specifications are found in Appendix A.

1-2

Model 1050 Padded Carrying Case: A carrying case for a

Model 6517A. Includes handles and shoulder strap.

General Information

Model 4288-1 Single Fixed Rack Mount Kit: Mounts a sin-

gle Model 6517A in a standard 19-inch rack.

Model 4288-2 Side-by-side Rack Mount Kit: Mounts two

instruments (Models 182, 428, 486, 487, 2001, 2002, 6517,
6517A, 7001) side-by-side in a standard 19-inch rack.

Model 4288-3 Side-by-side Rack Mount Kit: Mounts a

Model 6517A and a Model 199 side-by-side in a standard
19-inch rack.

Model 4288-4 Side-by-side Rack Mount Kit: Mounts a

Model 6517A and a 5
220, 224, 230, 263, 595, 614, 617, 705, 740, 775, etc.) side­by-side in a standard 19-inch rack.

Model 5156 Electrometer Calibration Standard Set: This

calibration fixture contains standardized resistors and capac­itors needed to calibrate the Model 6517A.

Model 6517-ILC-3 Safety Interlock Cable: Designed to

connect the lid interlock circuit of the Model 8009 test fix­ture to the interlock circuit of the Model 6517A.

Model 6517-RH Humidity Probe with Cable: This sensor

allows the Model 6517A to make relativ e humidity measure­ments (0 to 100%). Also included is an e xtension cable (part
number CA-129-1).

¼

-inch instrument (Models 195A, 196,

both ends with 3-slot male triax connectors. The -3 model is
3 ft. (0.9m) in length, the -10 model is 10 ft. (3m) in length,
and the -20 model is 20 ft. (6m) in length.

Model 7078-TRX-TBC Connector: This is a 3-lug female

triax bulkhead connector with cap for assembly of custom
panels and interface connections. Suitable for use with the
Model 6517A V-Source in high voltage applications.

Model 8002-ILC-3 Safety Interlock Cable: Designed to

connect the lid interlock circuit of the Model 8002A test fix­ture to the interlock circuit of the Model 6517A.

Model 8002A High Resistance T est Fixture: Used with the

Model 6517A to make accurate high resistance measure­ments of DUT. Designed to minimize leakage currents that
can corrupt the integrity of the measurement.

Model 8009 Resistivity Test Fixture: This is a guarded test

fixture for measuring volume and surface resistivities. It can
accommodate sheet samples 64 to 102mm (2-1/2 to 4 in.) in
diameter and up to 3.175mm (1/8 in.) thick.

Models 8501-1 and 8501-2 Trigger Link Cables: Connect

the Model 6517A to other instruments with Trigger Link
connectors (e.g., Model 7001 Switch System). The Model
8501-1 is one meter long; the Model 8501-2 is two meters
long.

Model 6517-TP Thermocouple with Leads: This type K

thermocouple sensor allows the Model 6517A to make exter ­nal temperature measurements from -190°C to 1350°C.

Model 6521 Low Current Scanner Card: This 10-channel

low current scanner card is terminated with BNC connectors
and plugs into the option slot of the Model 6517A.

Model 6522 Low Current/Low Voltage Scanner Card:

This 10-channel low current/low voltage scanner card is ter­minated with triax connectors and plugs into the option slot
of the Model 6517A.

Model 6524 Hi-R Software Package: Designed to aid in

making more repeatable high resistance/resistivity measure­ments. Four windows-driven programs increase measure­ment precision, ease download and analysis of Hi-R data,
and allow cross-correlation of environmental factors.

Models 7007-1 and 7007-2 Shielded IEEE-488 Cables:

Connect the Model 6517A to the IEEE-488 bus using shield­ed cables and connectors to reduce electromagnetic interfer­ence (EMI). The Model 7007-1 is one meter long; the Model
7007-2 is two meters long.

Models 7078-TRX-3, 7078-TRX-10 and 7078-TRX-20
Triax Cables: These are low noise triax cables terminated at

Model 8502 Trigger Link Adapter: Allows you to connect

the Trigger Link of the Model 6517A to instruments that use
the standard BNC (In/Out) external triggering technique.

Model 8530 IEEE-488 to Centronics Printer Adapter Ca­ble: Translates the IEEE-488 connector pinout and signal

level to a Centronics termination. This permits a standard
Centronics parallel printer to be connected to a Model
6517A in TALK-ONLY mode.

Model 8606 High Performance Probe Tip Kit: Consists of

two spade lugs, two alligator clips, and two spring hook test
probes. (The spade lugs and alligator clips are rated at 30V
RMS, 42.4V peak; the test probes are rated at 1000V.) These
components are designed to be used with high performance
test leads terminated with banana plugs, such as the Model
8607 High Performance Banana Cables.

Model 8607 High Performance Banana Cables: Consists

of two high voltage (1000V) banana cables. The cables are
terminated with banana plugs that have retractable sheaths.

CS-751 Barrel Adapter: This is a barrel adapter that allows

you to connect two triax cables together. Both ends of the
adapter are terminated with 3-lug female triax connectors.

1-3

2

Front Panel Operation

2.1 Introduction

This section contains detailed information for front panel op­eration of the Model 6517A. It is organized as follows:

2.2 Power-up — Covers information on connecting the in-

strument to line power, w arm-up period, default condi­tions, and the power-up sequence.

2.3 Display — Covers display formats, and messages as-

sociated with operation.

2.4 Connections — Electrometer input and voltage source

output: Provides basic information on the connections
used for typical electrometer and high-resistance meter
measurements. Summarizes guarding and shielding
techniques, and explains the potential hazards present­ed by floating circuits. Recommends cables and test
fixtures that can be used, and provides guidelines for
building a test fixture.

2.5 Voltage measurements — Provides the basic proce-

dure to measure voltage. Includes configuration infor­mation and measurement considerations for the volts
function.

2.6 Current measurements — Provides the basic proce-

dure to measure current. Includes configuration infor­mation and measurement considerations for the amps
function.

2.7 Resistance measurements — Provides the basic pro-

cedures to perform resistance and resistivity measure­ments. Includes configuration information, the
multiple display and measurement considerations for
the ohms function.

2.8 Charge measurements — Provides the basic proce-

dure to measure charge. Includes configuration infor-

mation, multiple displays and measurement consider­ations for the coulombs function.

2.9 Voltage source — Covers V-source operation includ-

ing how to use the safety interlock.

2.10 Analog outputs — Provides information needed to

use the 2V analog output and the preamp output.

2.11 Using external feedback — Explains how to use ex-

ternal feedback to extend the capabilities of the Model
6517A.

2.12 Range and resolution — Covers both manual and

auto ranging and resolution.

2.13 Zero check and relative — Provides details on the

zero check and relative (REL) features.

2.14 Test sequences — Covers the test sequences that can

be configured and run.

2.15 Triggering — Details types of trigger modes as well as

trigger sources that can be used.

2.16 Buffer — Covers use of the reading buffer including

programming the buffer size, recalling data and time
stamp.

2.17 Filter — Covers the use of the digital filter types that

can be used to reduce reading noise.

2.18 Math — Describes the calculations that can be per-

formed on readings.

2.19 Menu — Covers selections controlled from the main

menu, such as saving instrument setups, communica­tion configuration (GPIB and RS-232), and limits.

2.20 Scanning — Summarizes internal scanning using one

of the optional scanner cards, and explains how to use
the Model 6517A in an external scanning system.

2-1

Front Panel Operation

2.21 Other measurement considerations — Covers the

measurement considerations that generally apply to all
measurements.

2.22 Relative humidity and external temperature read­ings — Explains how to include these readings with

each volts, amps, ohms and coulombs measurement.

2.2 Power-up

2.2.1 Line power connections

Follow the procedure below to connect the Model 6517A to
line power and turn on the instrument.

1. First check to see that the line voltage selection switch
(see Figure 2-1) on the rear panel is in the correct posi­tion for the operating voltage in your area. The 115V po­sition is for line power in a voltage range from 90V to
125V. The 230V position is for line power in a voltage
range from 180V to 250V. The instrument will operate
at a line frequency of 50Hz, 60Hz or 400Hz.

CAUTION

Operating the instrument on an incor­rect line voltage may cause damage to
the instrument, possibly voiding the
warranty.

proper connections are made, instru­ment chassis is connected to power line
ground through the ground wire in the
power cord. Failure to use a grounded
outlet may result in personal injury or
death due to electric shock.

2.2.2 Line fuse replacement

A rear panel fuse located below the AC receptacle protects
the power line input of the instrument. If the fuse needs to be
replaced, perform the following steps:

WARNING

Make sure the instrument is disconnect­ed from the line and other equipment
before replacing the line fuse.

1. With the power off, place the end of a flat-blade screw­driver into the rear panel LINE FUSE holder. Push in
gently and rotate the fuse carrier one-quarter turn coun­terclockwise. Release pressure on the holder and its in­ternal spring will push the fuse carrier out of the holder.

2. Remove the fuse and replace it with the type recom­mended in Table 2-1.

SELECTED

LINE VOLTAGE

90-110V

105-125V

180-220V
210-250V

115V

Figure 2-1

Line voltage switch

2. Before plugging in the power cord, make sure the front
panel power switch is in the off (0) position.

3. Connect the female end of the supplied power cord to
the AC receptacle on the rear panel. Connect the other
end of the power cord to a grounded AC outlet.

WARNING

The power cord supplied with the Model
6517A contains a separate ground wire
for use with grounded outlets. When

CAUTION

Do not use a fuse with a higher current
rating than specified, or instrument
damage may occur. If the instrument re­peatedly blows fuses, locate and correct
the cause of the trouble before replacing
the fuse.

Install the new fuse and fuse carrier into the holder by revers­ing the above procedure.

Table 2-1

Line fuse selection

Keithley

Line voltage Fuse type

90-125V
180-250V

1/2A, 250V, Slo Blo
1/4A, 250V, Slo Blo

part no.

FU-71
FU-96-4

2-2

2.2.3 Power-up sequence

On power-up, the Model 6517A performs self-tests on its
EPROM and RAM, and checksum tests on data stored in
non-volatile memory . (See Table 2-2.) If a failure is detected,
the instrument momentarily displays an error message and
the ERR annunciator turns on. (Messages are listed in Table
2-3.)

NOTE

If a problem develops while the instru­ment is under warranty, return it to Kei­thley Instruments, Inc. for repair.

If the instrument passes the self-tests, the firmware revision
levels and the communications status are displayed. An ex­ample of this display is shown as follows:

Model 6517A

Rev. B12 A02 IEEE Addr=27 SCPI

The firmware revision levels (left to right) are for the main
microcontroller and display microcontroller. The revision
level number may be different in your particular unit. The
IEEE-488 address is its default value of 27 and the SCPI lan­guage is selected. DDC will be displayed if the DDC lan­guage is selected instead. If the RS-232 interface is selected,
the message “RS-232 enabled” is displayed instead of the
IEEE-488 address.

Next, if the unit is configured to display the calibration due
date at power-up, the unit shows the following:

Model 6517A

Calibration due: mmm/dd/yy

where “mmm” is the month abbreviation, “dd” is the day,
and “yy” is the year. If no calibration date is set, the display
shows that it is due now. (See the Model 6517 Service Man­ual to set the calibration due date and paragraph 2.19.3 of this
manual to set the display option.)

After the power-up sequence, the instrument begins its nor­mal display with zero check enabled (“Zero Check” dis­played).

Front Panel Operation

Table 2-2

Data checked on power-up

Data Type of storage

IEEE-488 address
Power-on default
Calibration constants
Calibration dates
Instrument setups
Reading buffer

Table 2-3

Power-up error messages

Message Action

Error +515,
Calibration dates lost

Error +514,
Calibration lost

Error +512,
Power-on state lost

Error +511,
GPIB address lost

Error +510,
Reading buffer data lost

Error -314,
Save/recall memory lost

Note: Any of these error conditions may occur the first time a unit is
turned on or after replacing the firmware.

Electrically-erasable PROM
Electrically-erasable PROM
Electrically-erasable PROM
Electrically-erasable PROM
10 in electrically-erasable PROM
Non-volatile RAM

The cal dates are set to factory
default values, but they are not
stored into EEPROM.
To do this, perform a compre­hensive calibration.
Cal constants are set to factory
default values, but they are not
stored into EEPROM. To do
this, perform a comprehensive
calibration.
Power-on defaults are reset to
factory defaults (bench) and
stored into EEPROM.
GPIB address is reset to factory
default (27) and stored into
EEPROM.
The reading buffer controls are
reset to factory defaults, but
they are not stored into
NVRAM. To do this, store read­ings in the buffer.
Instrument setup is reset to
bench defaults are stored in
EEPROM.

Power-up error messages

Error messages that may be displayed during power-up are
summarized in Table 2-3. These are shown when one of the
checksum tests of Table 2-2 fails.

2.2.4 Power-on default conditions

Power-on default conditions are those conditions the instru­ment assumes when it is first turned on. You can change these
power-on default conditions (e xcept the primary address) by
using the save setup feature that is av ailable with the MENU
key, as described in paragraph 2.19.1.

2-3

Front Panel Operation

µ

M Ω G Ω T Ω P Ω

Ω

Ω

Ω

Ω

Ω

e6 Ω e9 Ω

Depending on the installed memory option, either one, five,
or ten user-defined setups can be stored, any one of which
could be selected as the power-on default.

Table 2-30 in paragraph 2.19.1 lists the default conditions
that are set at the factory to optimize bench and GPIB (IEEE-

488) operation.

2.2.5 Warm-up period

The Model 6517A can be used within one minute after it is
turned on. However, the instrument should be turned on and
allowed to warm up for at least one hour before use to
achieve rated accuracy.

2.2.6 IEEE-488 primary address

The IEEE-488 primary address of the instrument must be the
same as the primary address you specify in the controller's
programming language. The default primary address of the
instrument is 27, but you can set the address to any value
from 0 to 30 by using the MENU key. Refer to paragraph

2.19.2 for step-by-step instructions on setting the primary
address.

Table 2-4

Typical display exponent values

Engineering units Scientific notation

Value Display Value Display

Picoamperes
Nanocoulombs
Microamperes
Milliamps
Kilo-ohms
Mega-ohms
Giga-ohms
Tera-ohms
Peta-ohms

pA
nC

A

mA

k Ω

10

10
10

10
10
10

10

10

10

-12

-9

-6

-3
3
6
9

12
15

A

e-12A
C
A
A

e-9C
e-6A
e-3A

e3 Ω

e12 Ω
e15 Ω

2.3.2 Information messages

Press the INFO key to view context-sensitive information
from most of the displays. An arrow (
tom line indicates that there is more information. Use the
cursor keys (

and

) to view the complete line. To exit
an INFO display, just press INFO, ENTER, EXIT or a func­tion key.

or

) on the bot-

2.3 Display

The display of the Model 6517A is primarily used to display
readings along with the units and type of measurement.
When not displaying readings, it is used for informational
messages, such as menu headings and selections. At the top
of the display are annunciators to indicate various states of
operation.

2.3.1 Exponent mode (Engineering or Scientific)

Readings on the display can be expressed in engineering
units or in scientific notation as shown in Table 2-4. In the
scientific mode, the exponent can be fixed to a specified val­ue, or it can be floating. In the floating mode, the instrument
will automatically select the exponent value.

All exponent mode selections are performed from the DIS­PLAY option of the GENERAL menu, which is part of the
MAIN MENU (see paragraph 2.19.7 for details).

Range messages

The following display messages may occur when making
measurements:

OVERFLOW — This message is displayed when the inte-

grated (average) input signal level (voltage, current, or
charge) exceeds 105% of full scale for the selected measure­ment range. For example, on the 20nA measurement range,
the OVERFLOW message occurs when the integrated input
level exceeds 21nA.

An OVERFLOW condition can be resolved by selecting a
higher measurement range, using AUTO range, or reducing
the magnitude of the input signal.

The OVERFLOW message will NOT occur during resis­tance or resistivity measurements.

UNDERFLOW — This condition is similar to OVER-

FLOW but pertains to resistance and resistivity measure­ments. An ohms measurement is performed by sourcing
voltage and measuring current. An ohms measurement that is
too low causes the current to exceed full scale. Thus, the
message UNDERFLOW is used to indicate that the mea­sured resistance or resistivity is lower than the lo wer limit of
the selected range.

2-4

Front Panel Operation

The UNDERFLOW condition can usually be resolved by se­lecting a lower ohms range or by using AUTO range. Para­graph 2.7 (Ohms Ranges) covers range limits and explains
how to select the optimum range for ohms measurements.

OUT OF LIMITS — This message indicates that a momen-

tary or transient out-of-range condition appeared at the input,
even though the integrated (or a verage) signal was within the
full scale range of the A/D con v erter. It usually indicates that
there is too much noise on the input signal for a valid mea­surement.

Generally, the OUT OF LIMITS condition can be eliminated
by better shielding of the signal source or by using other
noise reduction methods. Another solution is to select the
next higher range (or lower R range) to keep the transients
less than full scale.

The 2nA, 20nA, and 200nA ranges (and the R measurements
that use these current ranges) are particularly susceptible to
this condition because of the combination of speed and sen­sitivity.

A sine wave signal riding on a dc bias level is used to dem­onstrate an OUT OF LIMIT reading. Figure 2-A shows a
sine wave riding on a 20nA bias level. If this signal is mea­sured on the 200nA range at normal speed, it would simply
read 20nA (which is the dc average). If howe v er, you use the
20nA range, the positive peaks of the sine wave will be
clipped as shown in Figure 2-B. Clipping occurs at 110% of
full range (22nA on the 20nA range). Because of clipping,
the measurement of the input signal is significantly less than
20nA. To avoid these bad readings, the Model 6517A dis­plays the OUT OF LIMITS message instead of the inaccu­rate reading.

30

25

20

nA

15

10

Figure 2-A

Input signal

30

25

22
20

nA

15

10

DCA Reading on 200 nA range = 20nA

5

0

0

5

time 16.67ms

DCA Reading = <20nA

Note that the positive peaks of the input signal (which exceed
full scale) will not cause an OVERFLOW condition on the
20nA range since the average reading over the 16.67ms inte­gration period is less than full scale.

The A/D hardware limit detection circuit can be disabled,
which in turn disables the OUT OF LIMITS message. How­ever , the presence of OUT OF LIMIT readings may result in
measurements that are slightly, severely, or totally inaccu­rate. Paragraph 2.19.7 explains how to disable the OUT OF
LIMIT message.

When both OVERFLOW and OUT OF LIMITS conditions
occur, the OVERFLOW message will be displayed.

0

0

time 16.67ms

Figure 2-B

Measurement on 20nA range

2.3.3 Status and error messages

During Model 6517A operation and programming, you will
encounter a number of front panel messages. T ypical messag­es are either of status or error variety, as listed in Table 2-5.

The most recent status or error messages can be momentarily
displayed. Just enter a configuration menu or the main menu,
and press the PREV range key. (The display is blank if no
message is queued.)

2-5

Front Panel Operation

Table 2-5

Status and error messages

Number Description Event

-440

-430

-420

-410

-350

-330

-314

-285

-284

-282

-281

-260

-241

-230

-224

-223

-222

-221

-220

-215

-214

-213

-212

-211

-210

-202

-201

-200

-178

-171

-170

-168

-161

-160

-158

-154

-151

-150

-148

-144

-141

-140

-128

-124

-123

“Query UNTERMINATED after
indefinite response”
“Query DEADLOCKED”
“Query UNTERMINATED”
“Query INTERRUPTED”
“Queue overflow”

“Self T est failed”
“Save/recall memory lost”
“Program syntax error”
“Program currently running”
“Illegal program name”
“Cannot create program”

“Expression Error”
“Hardware missing”
“Data corrupt or stale”
“Illegal parameter value”
“Too much data”
“Parameter data out of range”

“Settings conflict”
“Parameter Error”
“Arm deadlock”
“Trigger deadlock”
“Init ignored”

“Arm ignored”
“Trigger ignored”
“Trigger error”
“Settings lost due to rtl”
“Invalid while in local”

“Execution error”
“Expression data not allowed”
“Invalid expression”
“Expression error”
“Block data not allowed”

“Invalid block data”
“Block data error”
“String data not allowed”
“String too long”
“Invalid string data”

“String data error”
“Character data not allowed”
“Character data too long”
“Invalid character data”
“Character data error”

“Numeric data not allowed”
“Too many digits in number”
“Exponent too large”

EE

EE
EE
EE
EE

EE
EE
EE
EE
EE
EE

EE
EE
EE
EE
EE
EE

EE
EE
EE
EE
EE

EE
EE
EE
EE
EE

EE
EE
EE
EE
EE

EE
EE
EE
EE
EE

EE
EE
EE
EE
EE

EE
EE
EE

Table 2-5 (cont.)

Status and error messages

Number Description Event

-121

-120

-114

-113

-112

-111

-110

-109

-108

-105

-104

-103

-102

-101

-100
000 “No Error” SE
+101

+121
+122
+123
+124
+125

+126
+161
+171
+172
+173
+174

+301
+302
+303
+304
+305

+306
+307
+308
+309
+310

+311
+312
+313
+315
+320
+321
+322

“Invalid character in number”
“Numeric data error”

“Header suffix out of range”
“Undefined header”
“Program mnemonic too long”
“Command Header Separator Error”
“Command Header Error”

“Missing Parameter”
“Parameter not allowed”
“GET not allowed.”
“Data T ype Error”
“Invalid Separator”

“Syntax Error”
“Invalid Character”
“Command Error”

“Operation Complete”
“Device calibrating”
“Device settling”
“Device ranging”
“Device sweeping”
“Device measuring”

“Device calculating”
“Program running”
“Waiting in trigger Layer”
“Waiting in arm layer 1”
“Waiting in arm layer 2”
“Re-entering the idle layer”

“Reading overflow”
“Low limit 1 event”
“High limit 1 event”
“Low limit 2 event”
“High limit 2 event”

“Reading A vailable”
“Voltmeter Complete”
“Buffer A v ailable”
“Buffer half full”
“Buffer full”

“Buffer Overflow”
“Buffer Pretriggered”
“Reading out of Limit”
“V-Source compliance detected”
“Buffer & Format element mismatch”
“Buffer Sizing error; set to MAX”
“Buffer Sizing error; set to MIN”

EE
EE

EE
EE
EE
EE
EE

EE
EE
EE
EE
EE

EE
EE
EE

SE
SE
SE
SE
SE
SE

SE
SE
SE
SE
SE
SE

SE
SE
SE
SE
SE

SE
SE
SE
SE
SE

SE
SE
SE
SE
EE
EE
EE

2-6

Front Panel Operation

Table 2-5 (cont.)

Status and error messages

Number Description Event

+350 to
427

+510
+511
+512
+513
+514
+515
+516
+517
+518
+519
+520
+521
+522

+610
+611
+612
+617
+618

Calibration commands (see Model
6517 Service Manual)

“Reading buffer data lost”
“GPIB address lost”
“Power-on state lost”
“Calibration data lost”
“Calibration dates lost”
“Calibration tolerances lost”
“Calibration tables lost”
“Voltage Offset lost”
“Current Offset lost”
“Installed option id lost”
“Option card not supported”
“Cal Card Data Error”
“GPIB communication language lost”

“Questionable Calibration”
“Questionable T emperature”
“Questionable Humidity”
“Questionable T est Sequence”
“Resistivity:I OutOfLimit”

EE
EE
EE
EE
EE
EE
EE
EE
EE
EE
EE
EE
EE

SE
SE
SE
SE

EE
+700 “Low Battery detected” EE
+800

+801
+802
+803
+804
+805
+806
+807
+808
+850
+851
+860
+861

“RS-232 Framing Error detected”
“RS-232 Parity Error detected”
“RS-232 Overrun detected”
“RS-232 Break detected”
“RS-232 Noise detected”
“Invalid system communication”
“RS-232 Settings Lost”
“RS-232 OFLO: Characters Lost”
“ASCII only with RS-232”
“Invalid Test Sequence Setting”
“Test Sequence Running”
“Interlock Violation Error”
"Vsource Limit too low for auto"

EE

EE

EE

EE

EE

EE

EE

EE

EE

EE

SE

EE

EE
+900 “Internal System Error” EE
+950

+951
+952
+953
+954
+955
+956
+957
+958

SE = Status event
EE = Error event

“DDC Reading overflow”
“DDC Reading Available”
“DDC Buffer full”
“DDC Mode IDDC Error”
“DDC Mode IDDCO Error”
“DDC Trigger Overrun Error”
“DDC No Remote Error”
“DDC Number Error”
“DDC Ready”

SE

SE

SE

EE

EE

EE

EE

EE

SE

2.3.4 Multiple displays

Each measurement function has its own set of “multiple dis­plays” shown in the bottom line of the front panel display.
The PREVious and NEXT DISPLAY keys scroll through the
selections for the present function.

The multiple displays can show a reading in a different form,
or give additional information about the reading, for exam­ple:

• T op line shows a reading; bottom line sho ws a zero-cen­ter bar graph with adjustable limits.

To scroll through the multiple displays available for each
measurement functions, repeatedly press and release the
NEXT DISPLAY key. The same action with the PREVious
DISPLAY key does a reverse scroll through the displays. To
return to the default reading display, just press and hold ei­ther key.

Multiple displays that are specific to a particular function or
operation are discussed later in this section, such as the cal­culations display in math (see Table 2-6 for paragraph refer­ences). Some of the displays that are common to all
measurement functions are discussed here.

Time/Day/Date

This display provides the time, day of week, and the date.
The time, date and format (12-hour or 24-hour) are set from
the CLOCK option of the GENERAL MENU (which is se­lected from the MAIN MENU). See paragraph 2.19.7
(CLOCK) for details.

Table 2-6

Multiple (Next) displays by function

Paragraph

Function Next display

All Time, day and date

Bar graph
Zero-centered bar graph
Maximum and minimum values
Relative and actual values
Calculated and actual values
Limits bar graph
Relative humidity and external
temperature stamp

R Source (V) and measure (I) values 2.7.4

reference

2.3.4

2.3.4

2.3.4

2.3.4

2.13.3

2.18.7

2.19.5

2.3.4

2-7

Front Panel Operation

Bar graph

The “normal” bar graph, with a zero at the left end, is a
graphical representation of a reading as a portion of a range.
(See Figure 2-2.) The vertical lines displayed along the bar
designate 0%, 25%, 50%, 75%, and 100% of full scale. Each
full segment of the bar represents approximately 4% of the
range limit.

The right endpoint of the bar graph is plus full scale of the
present range for positive readings, and minus full scale for
negative readings. When the 100% line changes to an arrow,
the reading exceeds the present range.

-11.9685

0

25% of

full range

V

-20V

Full

Range

50% of

full range

75% of full range

Figure 2-2

Bar graph (zero-at-left) multiple display

Zero-centered bar graph

wise, values greater than 1% (such as 1.67%) are shown
rounded to the nearest integer percent.

Perform the following to view or change the plus and minus
percentage of range:

1. From a measurement function, press CONFIG and then
NEXT or PREV DISPLAY . The following is displayed:

ZERO-BARGRAPH+/-50.00%

2. Change the percentage by using the cursor keys and the
RANGE ▲ and ▼ keys to enter a numeric value (0.01 -

99.99%). Press ENTER when done.

Maximum and minimum

The maximum and minimum multiple display shows the
maximum and minimum readings since the display was en­tered. (See Figure 2-4.) The maximum and minimum values
are reset by the following:

• Pressing the present function key.

• Leaving the display by changing function or entering a
menu.

The resolution, units, and prefix on the bottom line are the
same as shown for top line reading.

The zero-centered bar graph is a graphical representation of
a reading with plus and minus limits. (See Figure 2-3.) The
limits are expressed in a user-selectable percentage of range.

The vertical lines displayed along the bar designate the plus
and minus limits, zero, and halfway to either limit. There are
ten full segments between zero and each end, so each full
segment represents 10% of the limit. When a line at the limit
changes to an arrow, the reading exceeds the programmed
range.

-05.9577
50%

-50% of range

-25% of range

V

+50V

+50% of range

25% of range

0%

Figure 2-3

Zero-centered bar graph multiple display

The plus and minus percentage of range that is programmed
(0.01 - 99.99%) applies to all functions. Because of round­ing, values greater than 99.5% are shown as 100% and, like-

-15.8286

Max = -05.7460

Maximum

value

V

Min = -15.8286

Minimum

value

Figure 2-4

Maximum and minimum multiple display

Relative humidity and external temperature

This display provides the relative humidity and the external
temperature readings. Note that the appropriate sensors have
to be connected to instrument, and they have to be enabled in
order to get valid readings. (See paragraph 2.22 for details.)

2.3.5 Navigating menus

There are basically two types of menu structures; the Main
Menu and the Configure menus. The Main Menu accesses
items for which there are no dedicated keys, and Configure
menus are used to configure measurement functions and oth­er instrument operations.

2-8

Front Panel Operation

Use the following rules to navigate through the menu struc­ture:

1. The top level of the Main Menu is accessed by pressing
the MENU key. A Configuration menu is accessed by
pressing CONFIG and then the desired function (V, I,
etc.) or operation (TRIG, STORE, etc.).

2. A menu item is selected by placing the cursor on it and
pressing ENTER. Cursor position is denoted by the
blinking menu item or parameter. The cursor keys (
and ) control cursor position.

3. A displayed arrow ( and ) on the bottom line indi­cates that there are one or more additional items (mes­sages) to select from. Use the appropriate cursor key to
display them.

4. A numeric parameter is keyed in by placing the cursor
on the digit to be changed and using the RANGE ▲ or
▼ key to increment or decrement the digit.

5. A change is only executed when ENTER is pressed. En­tering an invalid parameter generates an error and the
entry is ignored.

6. The EXIT key is used to back out of the menu structure.
Any change that is not entered is cancelled when EXIT
is pressed. The EXIT key has additional actions and are
summarized in Table 2-7.

7. The VOL T A GE SOURCE ▼ and ▲ keys are used adjust
the V-Source value. The V-Source is decremented or in­cremented by placing the cursor on the desired digit and
pressing ▼ or ▲. With the cursor on the polarity sign,
pressing ▼ or ▲ toggles the polarity. Pressing CONFIG
and then ▼ or ▲ displays the CONFIGURE V­SOURCE menu.

2.4 Connections — electrometer , high­resistance meter , and V -source

ing. The concepts of guarding and floating circuits are
introduced here.

NOTE

Detailed connection schemes are included
with the measurement procedures (see
paragraphs 2.5.1, 2.6.1, 2.7.1 and 2.8.1).

2.4.1 Electrometer input connector

The rear panel triax INPUT connector is a 3-lug female triax
connector that will mate to a cable terminated with a 3-slot
male triax connector.

Input configurations — As shown in Figure 2-5, the input
connector can be configured in two ways. With GUARD off
(Figure 2-5A), input low is connected to the inner shell of the
connector. This configuration is used for current, resistance,
coulombs and unguarded voltage measurements.

NOTE

Where possible, make input low connec­tions directly to the INPUT connector low
terminal instead of using COMMON to
avoid internal voltage drops that may af­fect measurement accuracy.

With GU ARD on (Figure 2-5B), guard is connected to the in­ner shell of the triax connector. Input low is accessed via the
COMMON binding post through an internal 1Ω resistor.
This configuration is used for guarded voltage measurements
only. Note that guard can only be enabled (on) for the volts
function. For ohms, amps and coulombs, guard is always dis­abled (off). For voltage measurements, guard is enabled or
disabled from the Configure Voltage menu structure as ex­plained in paragraph 2.5.2.

The following information provides basic information on
electrometer, high-resistance meter, and V-source connec­tions. Also co vered is the use of lo w-noise cables and shield-

Table 2-7

EXIT key actions

Condition EXIT key action

Temporary message displayed
(e.g., TRIGGERS HAL TED)
INFO message displayed
Reading display hold
Scanning
Data storage

Cancels display of temporary message.

Cancels INFO message, returns to menu or normal reading display.
Cancels reading display hold, resumes normal reading display.
Disables scanning. Also stops data storage if enabled.
Stops data storage. Temporary message STORAGE INTERRUPTED
is displayed.

The INPUT triax connector is also used for the Force Voltage
Measure Current configuration. This configuration utilizes
the V-source to make resistance measurements (see para­graph 2.4.2) and current measurements (see paragraph

2.4.3).

2-9

Front Panel Operation

INPUT

250V PEAK

Volts, Amps, Ohms & Coulombs

A. Unguarded (GUARD off)

Input High

Guard
Chassis

INPUT

250V PEAK

Volts only

Ground

B. Guarded (GUARD on)

Figure 2-5

Input connector configurations

Input High

Input Low

Chassis Ground

COMMON

1Ω

Input Low

Input High

Input Low

Chassis Ground

* Max Input Signal - 250VRMS, DC to 60Hz sine wave
(10 seconds maximum in mA ranges).

Figure 2-6

Maximum input levels

S

V

Max Input Signal *

500V Peak

Capacitor

Under Test

500V Peak

6517A

A

Ammeter

Maximum input levels — The maximum input levels to the
Model 6517A are summarized in Figure 2-6.

WARNING

The maximum common-mode input
voltage (the voltage between input low
and chassis ground) is 500V peak. Ex­ceeding this value may create a shock
hazard.

CAUTION

Connecting PREAMP OUTPUT, COM­MON, or 2V ANALOG OUTPUT to
earth while floating the input may dam­age the instrument.

Input protection — The Model 6517A incorporates protec-

tion circuitry against nominal overload conditions. Howe ver ,
a high voltage (>250V) and resultant current surge could
damage the input circuitry. A typical test circuit to measure
the leakage current of a capacitor is shown in Figure 2-7.
When Switch S is closed, an initial surge of charging current
will flow and the high voltage will be seen across the input
of the Model 6517A.

Figure 2-7

Capacitor test circuit without protection

Adding a resistor and two diodes (1N3595) as shown in Fig­ure 2-8 will provide considerable extra protection. The resis­tor must be large enough to limit the current through the
diodes to 10mA or less. It must also be large enough to with­stand the supply voltage. The protection circuit should be en­closed in a light-tight conductive shield.

This same protection circuit is useful when measuring the in­sulation resistance of films or high-voltage cables. Without
such added protection, a pinhole or other defect could cause
an arc, destroying the electrometer input.

Protection Circuit

S

Capacitor

Under Test

V

R

D1 D2

HI

A

LO

6517A

Ammeter

Figure 2-8

Capacitor test circuit with protection

2-10