Tektronix Series 3700A System Switch Multimeter Application Manual Application Manual
tek.com/keithley
Series 3700A System Switch/Multimeter
Application Manual
3700AS-904-01 Rev. C March 2021
*P3700AS-904-01C*
3700AS-904-01C
System Switch/Multimeter
Application Manual
Series 3700A
© 2021, Keithley Instruments, LLC
Cleveland, Ohio, U.S.A.
All rights reserved.
Any unauthorized reproduction, photocopy, or use of the information herein, in whole or in part,
without the prior written approval of Keithley Instruments, LLC, is strictly prohibited.
These are the original instructions in English.
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Document number: 3700AS-904-01 Rev. C March 2021
Safety precautions
The following safety precautions should be observed before using this product and any associated instrumentation. Although
some instruments and accessories would normally be used with nonhazardous voltages, there are situations where hazardous
conditions may be present.
This product is intended for use by personnel who recognize shock hazards and are familiar with the safety precautions required
to avoid possible injury. Read and follow all installation, operation, and maintenance information carefully before using the
product. Refer to the user documentation for complete product specifications.
If the product is used in a manner not specified, the protection provided by the product warranty may be impaired.
The types of product users are:
Responsible body is the individual or group responsible for the use and maintenance of equipment, for ensuring that the
equipment is operated within its specifications and operating limits, and for ensuring that operators are adequately trained.
Operators use the product for its intended function. They must be trained in electrical safety procedures and proper use of the
instrument. They must be protected from electric shock and contact with hazardous live circuits.
Maintenance personnel perform routine procedures on the product to keep it operating properly, for example, setting the line
voltage or replacing consumable materials. Maintenance procedures are described in the user documentation. The procedures
explicitly state if the operator may perform them. Otherwise, they should be performed only by service personnel.
Service personnel are trained to work on live circuits, perform safe installations, and repair products. Only properly trained
service personnel may perform installation and service procedures.
Keithley products are designed for use with electrical signals that are measurement, control, and data I/O connections, with low
transient overvoltages, and must not be directly connected to mains voltage or to voltage sources with high transient
overvoltages. Measurement Category II (as referenced in IEC 60664) connections require protection for high transient
overvoltages often associated with local AC mains connections. Certain Keithley measuring instruments may be connected to
mains. These instruments will be marked as category II or higher.
Unless explicitly allowed in the specifications, operating manual, and instrument labels, do not connect any instrument to mains.
Exercise extreme caution when a shock hazard is present. Lethal voltage may be present on cable connector jacks or test
fixtures. The American National Standards Institute (ANSI) states that a shock hazard exists when voltage levels greater than
30 V RMS, 42.4 V peak, or 60 VDC are present. A good safety practice is to expect that hazardous voltage is present in any
unknown circuit before measuring.
Operators of this product must be protected from electric shock at all times. The responsible body must ensure that operators
are prevented access and/or insulated from every connection point. In some cases, connections must be exposed to potential
human contact. Product operators in these circumstances must be trained to protect themselves from the risk of electric shock. If
the circuit is capable of operating at or above 1000 V, no conductive part of the circuit may be exposed.
Do not connect switching cards directly to unlimited power circuits. They are intended to be used with impedance-limited
sources. NEVER connect switching cards directly to AC mains. When connecting sources to switching cards, install protective
devices to limit fault current and voltage to the card.
Before operating an instrument, ensure that the line cord is connected to a properly-grounded power receptacle. Inspect the
connecting cables, test leads, and jumpers for possible wear, cracks, or breaks before each use.
When installing equipment where access to the main power cord is restricted, such as rack mounting, a separate main input
power disconnect device must be provided in close proximity to the equipment and within easy reach of the operator.
For maximum safety, do not touch the product, test cables, or any other instruments while power is applied to the circuit under
test. ALWAYS remove power from the entire test system and discharge any capacitors before: connecting or disconnecting
cables or jumpers, installing or removing switching cards, or making internal changes, such as installing or removing jumpers.
Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth)
ground. Always make measurements with dry hands while standing on a dry, insulated surface capable of withstanding the
voltage being measured.
For safety, instruments and accessories must be used in accordance with the operating instructions. If the instruments or
accessories are used in a manner not specified in the operating instructions, the protection provided by the equipment may be
impaired.
Do not exceed the maximum signal levels of the instruments and accessories. Maximum signal levels are defined in the
specifications and operating information and shown on the instrument panels, test fixture panels, and switching cards.
When fuses are used in a product, replace with the same type and rating for continued protection against fire hazard.
Chassis connections must only be used as shield connections for measuring circuits, NOT as protective earth (safety ground)
connections.
If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation requires the use
of a lid interlock.
If a screw is present, connect it to protective earth (safety ground) using the wire recommended in the user documentation.
The symbol on an instrument means caution, risk of hazard. The user must refer to the operating instructions located in the
user documentation in all cases where the symbol is marked on the instrument.
The symbol on an instrument means warning, risk of electric shock. Use standard safety precautions to avoid personal
contact with these voltages.
The symbol on an instrument shows that the surface may be hot. Avoid personal contact to prevent burns.
The symbol indicates a connection terminal to the equipment frame.
If this symbol is on a product, it indicates that mercury is present in the display lamp. Please note that the lamp must be
properly disposed of according to federal, state, and local laws.
The WARNING heading in the user documentation explains hazards that might result in personal injury or death. Always read
the associated information very carefully before performing the indicated procedure.
The CAUTION heading in the user documentation explains hazards that could damage the instrument. Such damage may
invalidate the warranty.
The CAUTION heading with the symbol in the user documentation explains hazards that could result in moderate or minor
injury or damage the instrument. Always read the associated information very carefully before performing the indicated
procedure. Damage to the instrument may invalidate the warranty.
Instrumentation and accessories shall not be connected to humans.
Before performing any maintenance, disconnect the line cord and all test cables.
To maintain protection from electric shock and fire, replacement components in mains circuits — including the power
transformer, test leads, and input jacks — must be purchased from Keithley. Standard fuses with applicable national safety
approvals may be used if the rating and type are the same. The detachable mains power cord provided with the instrument may
only be replaced with a similarly rated power cord. Other components that are not safety-related may be purchased from other
suppliers as long as they are equivalent to the original component (note that selected parts should be purchased only through
Keithley to maintain accuracy and functionality of the product). If you are unsure about the applicability of a replacement
component, call a Keithley office for information.
Unless otherwise noted in product-specific literature, Keithley instruments are designed to operate indoors only, in the following
environment: Altitude at or below 2,000 m (6,562 ft); temperature 0 °C to 50 °C (32 °F to 122 °F); and pollution degree 1 or 2.
To clean an instrument, use a cloth dampened with deionized water or mild, water-based cleaner. Clean the exterior of the
instrument only. Do not apply cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Products that
consist of a circuit board with no case or chassis (e.g., a data acquisition board for installation into a computer) should never
require cleaning if handled according to instructions. If the board becomes contaminated and operation is affected, the board
should be returned to the factory for proper cleaning/servicing.
Safety precaution revision as of June 2017.
Introduction .............................................................................................................. 1-1
Welcome .............................................................................................................................. 1-1
Introduction to this manual ................................................................................................... 1-1
About the Series 3700A examples ....................................................................................... 1-2
Contact information .............................................................................................................. 1-2
Extended warranty ............................................................................................................... 1-2
Safety precautions for connections ...................................................................................... 1-3
Scanning examples .................................................................................................. 2-1
Scanning examples .............................................................................................................. 2-1
Scan the card with no measurement (switch-only) .............................................................. 2-1
Scan the card and make measurements ............................................................................. 2-2
Make 4-wire ohm measurements using a background scan ............................................... 2-3
Scan, measure, and store .................................................................................................... 2-4
Optimize scan for speed ...................................................................................................... 2-5
Fast dc volt measurement .................................................................................................... 2-7
AC volts Autodelay Once script ........................................................................................... 2-9
Fast alternating scan, dc volts, and two-wire ohms ........................................................... 2-11
Thermocouple measurement using the front panel ........................................................... 2-13
Thermocouple measurement using a remote interface ..................................................... 2-14
TSP-Link and interactive triggers ........................................................................... 3-1
TSP-Link and interactive triggers ......................................................................................... 3-1
Set up communication.......................................................................................................... 3-1
Logical block diagram of test connections ........................................................................... 3-3
Example program code ........................................................................................................ 3-4
Program code to run the test ............................................................................................... 3-7
Using the scanning and triggering model .............................................................. 4-1
Using the scanning and triggering model............................................................................. 4-1
Set up communication.......................................................................................................... 4-1
Program code ....................................................................................................................... 4-2
Program code to run the test ............................................................................................... 4-5
Using background scans for longer scan lists...................................................................... 4-6
Table of contents
Table of contents Series 3700A System Switch/Multimeter Application Manual
IEEE-1588 in Series 3700A-based systems ............................................................ 5-1
IEEE-1588 in Series 3700A-based systems ........................................................................ 5-1
Scheduling alarms ................................................................................................................ 5-1
Scheduling alarms on a stand-alone Series 3700A ............................................................. 5-2
Measurement examples ........................................................................................... 6-1
External DMM and switch triggering .................................................................................... 6-1
DMM buffer statistics with interactive operation .................................................................. 6-5
Commonside ohm measurement with Model 3721 ............................................................. 6-7
Next steps ................................................................................................................. 7-1
Next steps ............................................................................................................................ 7-1
In this section:
Welcome .................................................................................. 1-1
Introduction to this manual ....................................................... 1-1
About the Series 3700A examples ........................................... 1-2
Contact information .................................................................. 1-2
Extended warranty ................................................................... 1-2
Safety precautions for connections .......................................... 1-3
Welcome
Thank you for choosing a Keithley Instruments product. The Series 3700A System Switch/Multimeter
features scalable, instrument grade switching and multi-channel measurement solutions that are
optimized for automated testing of electronic products and components. The Series 3700A includes
four versions of the Model 3706A system switch mainframe, along with a growing family of plug-in
switch and control cards. When the Model 3706A mainframe is ordered with the high performance
multimeter, you receive a tightly-integrated switch and measurement system that can meet the
demanding application requirements in a functional test system or provide the flexibility needed in
stand-alone data acquisition and measurement applications.
Introduction to this manual
This manual provides application examples that demonstrate how to use the instrument in specific
situations.
For detailed information about the Series 3700A, refer to the Series 3700A Reference Manual.
Section 1
Introduction
Section 1: Introduction Series 3700A System Switch/Multimeter Application Manual
1-2
About the Series 3700A examples
This section shows you how to use the Series 3700A for a variety of uses.
To use the Test Script Processor (TSP®) commands and run the examples in this manual, you can
use Keithley Test Script Builder (TSB) software or TSB Embedded.
TSB is a software tool that simplifies building test scripts for Keithley Instruments that are enabled to
use Test Script Processor (TSP®). For more information about using the TSB software, refer to "Using
Test Script Builder (TSB)" in the Series 3700A Reference Manual. You can download the TSB
software from the Product Support and Downloads web page (tek.com/product-support).
TSB Embedded is a script management tool that is available through the web interface of the
instrument. You can use TSB Embedded to create, modify, and save test scripts, and to send
individual commands. TSB Embedded provides some of the features of Test Script Builder (TSB). For
more information about using TSB Embedded, see "Using the web interface" in the Series 3700A
Reference Manual.
Contact information
If you have any questions after you review the information in this documentation, please contact your
local Keithley Instruments office, sales partner, or distributor. You can also call the Tektronix
corporate headquarters (toll-free inside the U.S. and Canada only) at 1-800-833-9200. For worldwide
contact numbers, visit tek.com/contact-us.
Extended warranty
Additional years of warranty coverage are available on many products. These valuable contracts
protect you from unbudgeted service expenses and provide additional years of protection at a fraction
of the price of a repair. Extended warranties are available on new and existing products. Contact your
local Keithley Instruments office, sales partner, or distributor for details.
3700AS-904-01 Rev. C March 2021
Series 3700A System Switch/Multimeter Application Manual Section 1: Introduction
1-3
Safety precautions for connections
Connection information for switching cards is intended for qualified service personnel. Do
not attempt to connect DUT or external circuitry to a switching card unless qualified to do so.
To prevent electric shock that could result in serious injury or death, comply with these
safety precautions:
Before making or breaking any connections to the switching card, make sure the Series
3700A is turned off and power is removed from all external circuitry.
Do not connect signals that will exceed the maximum specifications of any installed
switching card.
If both the rear analog backplane connector of the Series 3700A and the switching card
terminals are connected at the same time, the test lead insulation must be rated to the
highest voltage that is connected. For example, if 300 V is connected to the analog backplane
connector, the test lead insulation for the switching card must also be rated for 300 V.
Dangerous arcs of an explosive nature in a high-energy circuit can cause severe personal
injury or death if contacted. If the multimeter is connected to a high-energy circuit when set
to a current range, low-resistance range, or any other low-impedance range, the circuit is
virtually shorted.
Dangerous arcing can result (even when the multimeter is set to a voltage range) if the
minimum voltage spacing is reduced in the external connections. For details about how to
safely make high-energy measurements, see “High-energy circuit safety precautions” in the
Series 3700A Reference Manual.
As described in the International Electrotechnical Commission (IEC) Standard IEC 664, the
Series 3700A is Installation Category I and must not be connected to mains.
3700AS-904-01 Rev. C March 2021
In this section:
Scanning examples .................................................................. 2-1
Scan the card with no measurement (switch-only) ................... 2-1
Scan the card and make measurements .................................. 2-2
Make 4-wire ohm measurements using a background scan .... 2-3
Scan, measure, and store ........................................................ 2-4
Optimize scan for speed .......................................................... 2-5
Fast dc volt measurement ........................................................ 2-7
AC volts Autodelay Once script ................................................ 2-9
Fast alternating scan, dc volts, and two-wire ohms ................ 2-11
Thermocouple measurement using the front panel ................ 2-13
Thermocouple measurement using a remote interface .......... 2-14
Scanning examples
The examples in this section demonstrate how to set up scanning scripts.
In the examples, to clear a trigger stimulus after setting, set the stimulus to 0, which returns the
stimulus setting to its factory default value, which may or may not be 0.
Scan the card with no measurement (switch-only)
This example assumes a Keithley Instruments Model 3720 card is installed in slot 3 of a Series 3700A.
This example scans all channels in a slot in a switch-only application (no measurements are made).
Digital I/O line 1 is used to initiate a background scan.
Code description
Reset the Series 3700A to factory defaults.
Create a scan for all channels on the card installed in slot 3.
Set up digital I/O line 1 to detect a falling-edge trigger.
Use the digital I/O event as the stimulus of the arm layer of the trigger model.
Start the scan and run it in the background.
Program code example
reset()
scan.create("slot3")
digio.trigger[1].mode = digio.TRIG_FALLING
scan.trigger.arm.stimulus = digio.trigger[1].EVENT_ID
scan.background()
Section 2
Scanning examples
Section 2: Scanning examples Series 3700A System Switch/Multimeter Application Manual
2-2
Scan the card and make measurements
The following example assumes a Keithley Instruments Model 3720 card is installed in slot 3 of a
Series 3700A.
The program code scans the entire card while measuring dc volts on each channel and stored
readings in a buffer called DCVbuffer.
Code description
Reset the Series 3700A to factory defaults.
For the DMM function:
• Set the DMM function to measure dc volts.
• Set the dc volt range to 10 volts.
• Set the number of power line cycles (NPLC) over which a measurement is integrated to 0.1. This
helps improve measurement quality by canceling line noise.
• Save the DMM configuration as measureDCV.
• Make a buffer named DCVbuffer and configure it to store up to 1000 readings.
Set up digital I/O line 1 to detect a falling-edge trigger.
For the scan:
• Use a digital I/O event as the stimulus to close each channel.
• Set bypass to off so that first channel needs to see a trigger before closing.
• Create a scan for channels 1 to 60 on the card installed in slot 3.
• Start the scan and run the scan in the background. Readings are saved to the DVCbuffer buffer.
Example program code
reset()
dmm.func = "dcvolts"
dmm.range = 10
dmm.nplc = 0.1
dmm.configure.set("measureDCV")
DCVbuffer = dmm.makebuffer(1000)
digio.trigger[1].mode = digio.TRIG_FALLING
scan.trigger.channel.stimulus = digio.trigger[1].EVENT_ID
scan.bypass = scan.OFF
scan.create("3001:3060", "measureDCV")
scan.background(DCVbuffer)
3700AS-904-01 Rev. C March 2021
Series 3700A System Switch/Multimeter Application Manual Section 2: Scanning examples
2-3
Make 4-wire ohm measurements using a background scan
The following example assumes a Keithley Instruments Model 3720 card is installed in slot 4 of Series
3700A. This script scans all the channels in slot 4 and makes 4-wire ohm measurements using a
background scan.
Code description
Reset the Series 3700A to factory defaults.
For the DMM functions, set the DMM function and the configuration for all channels in slot 4 to
four-wire ohm measurements.
Create a scan for all channels on the card installed in slot 4.
Set digital I/O lines 1 and 2 to detect a falling-edge trigger.
Set up the scan as follows:
• Close each channel with a measurement complete event.
• Pulse digital I/O line 2 when a channel ready event occurs.
• Trigger each measurement with a digital I/O line 1 event trigger.
• Set bypass to on so that the first channel closes without making a measurement.
Create a buffer named 4WBuffer that stores up to 1000 readings.
Start the scan and run the scan in the background. Save readings to the 4WBuffer buffer.
The example program code to use a background scan to make 4-wire ohm measurements:
reset()
dmm.func = "fourwireohms"
dmm.setconfig("slot4", "fourwireohms")
scan.create("slot4")
digio.trigger[1].mode = digio.TRIG_FALLING
digio.trigger[2].mode = digio.TRIG_FALLING
scan.trigger.channel.stimulus = scan.trigger.EVENT_MEASURE_COMP
digio.trigger[2].stimulus = scan.trigger.EVENT_CHANNEL_READY
scan.trigger.measure.stimulus = digio.trigger[1].EVENT_ID
scan.bypass = scan.ON
4WBuffer = dmm.makebuffer(1000)
scan.background(4WBuffer)
3700AS-904-01 Rev. C March 2021
Section 2: Scanning examples Series 3700A System Switch/Multimeter Application Manual
2-4
Scan, measure, and store
The following example assumes a Keithley Instruments Model 3723 card is installed in slot 3 of a
Series 3700A.
This program code:
• Scans the entire Model 3723 card.
• Measures dc volts on each channel.
• Stores readings in a buffer called DCvoltBuffer.
For the Model 3723, the channels are reed relays and the analog backplane relays are
electromechanical relays. Therefore, to have the scan run faster, this example sets the scan mode to
fixed ABR, which closes the backplane relays before scanning starts and keeps them closed during
the entire scan.
Code description
Reset the Series 3700A to factory defaults.
For the DMM functions:
• Set the DMM function to measure dc volts.
• Set the dc volt range to 10 volts.
• Set the number of power line cycles (NPLC) over which a measurement is integrated to 0.1. This
helps improve measurement quality by canceling line noise.
• Save the DMM configuration as DCVreadings.
• Make a buffer named DCvoltBuffer and configure it to store up to 1000 readings.
Set up digital I/O line 1 to detect a falling-edge trigger.
For the scan:
• Set each channel so it closes with a digital I/O line 1 event trigger.
• Set bypass to off so that the first channel needs to see the trigger before closing.
• Set the mode to fixed ABR so that the backplane relays are closed at the start of the scan and
maintained closed throughout the scan without being opened or closed.
• Create a scan list of channels 1 to 60 on slot 3.
• Start the scan to execute in the background and save readings to a buffer called DCvoltBuffer.
3700AS-904-01 Rev. C March 2021
Series 3700A System Switch/Multimeter Application Manual Section 2: Scanning examples
2-5
Program code example
reset()
dmm.func = "dcvolts"
dmm.range = 10
dmm.nplc = 0.1
dmm.configure.set("DCVreadings")
DCvoltBuffer = dmm.makebuffer(1000)
digio.trigger[1].mode = digio.TRIG_FALLING
scan.trigger.channel.stimulus = digio.trigger[1].EVENT_ID
scan.bypass = scan.OFF
scan.mode = scan.MODE_FIXED_ABR
scan.create("3001:3060", "DCVreadings")
scan.background(DCvoltBuffer)
Optimize scan for speed
The following example assumes a Keithley Instruments Model 3723 card is installed in slot 1 of a
Series 3700A.
Some cards, such as the Model 3723, use relays that are optimized for switching speed and reliability.
However, these cards still use backplane relays, which are slow. To achieve the full speed and
reliability of the card, avoid scan modes (scan.mode) that intelligently open and close backplane
relays, such as scan.MODE_OPEN_SELECTIVE. Instead, you can set the scan mode to
scan.MODE_FIXED_ABR, which closes all required backplane relays before the start of the scan and
keeps them closed until you program them to open.
The following is an example of a Series 3700A configured for fast scanning with the Model 3723 card.
Sixty channels are scanned ten times on 200 V dc.
The NPLC setting is at 0.006 in the example. The fastest NPLC setting supported in a Series 3700A
is 0.0005. Another speed improvement option is to set the channel connect rule to OFF
(channel.connectrule = channel.OFF). Using this setting allows channels to open and close
at the same time if the application supports this operation.
3700AS-904-01 Rev. C March 2021
Section 2: Scanning examples Series 3700A System Switch/Multimeter Application Manual
2-6
Code description
Reset the Series 3700A to factory defaults.
For the DMM function:
• Set the DMM function to measure dc volts.
• Turn autorange off.
• Set the range to 200 volts.
• Turn autozero off.
• Set the NPLC to 0.006.
• Turn auto delay off.
• Create a reading buffer named reading_buffer that can hold up to 600 readings.
• Save the current DMM settings as the configuration Chan1to60dcvolts.
• Assign the configuration Chan1to60dcvolts to channels 1 to 60 on slot 1.
For the scan:
• Set the scan mode to fixed ABR.
• Create a scan list of channels 1 to 60 on slot 1.
• Set the scan count to 10.
• Scan in the foreground.
• Write the data out to a file on a USB flash drive.
Program code example
reset()
dmm.func = "dcvolts"
dmm.autorange = dmm.OFF
dmm.range = 200
dmm.autozero = dmm.OFF
dmm.nplc = 0.006
dmm.autodelay = dmm.OFF
reading_buffer = dmm.makebuffer(600)
dmm.configure.set("Chan1to60dcvolts")
dmm.setconfig("1001:1060", "Chan1to60dcvolts")
scan.mode = scan.MODE_FIXED_ABR
scan.create("1001:1060")
scan.scancount = 10
scan.execute(reading_buffer)
dmm.savebuffer("reading_buffer", "/usb1/mydata.csv")
3700AS-904-01 Rev. C March 2021
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