User Manual
VX4237
Digital Multimeter Module
070-9075-02
This document supports firmware version 1.00
Warning
The servicing instructions are for use by qualified
personnel only. To avoid personal injury, do not
perform any servicing unless you are qualified to
do so. Refer to the Safety Summary prior to
performing service.
Copyright T ektronix, Inc. 1994. All rights reserved. Licensed software products are owned by Tektronix or its suppliers
and are protected by United States copyright laws and international treaty provisions.
Use, duplication, or disclosure by the Government is subject to restrictions as set forth in subparagraph (c)(1)(ii) of the
Rights in T echnical Data and Computer Software clause at DFARS 252.227-7013, or subparagraphs (c)(1) and (2) of the
Commercial Computer Software – Restricted Rights clause at F AR 52.227-19, as applicable.
T ektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes
that in all previously published material. Specifications and price change privileges reserved.
Printed in the U.S.A.
T ektronix, Inc., P.O. Box 1000, Wilsonville, OR 97070–1000
TEKTRONIX and TEK are registered trademarks of T ektronix, Inc.
WARRANTY
T ektronix warrants that this product will be free from defects in materials and workmanship for a period of three (3) years
from the date of shipment. If any such product proves defective during this warranty period, T ektronix, at its option, either
will repair the defective product without charge for parts and labor, or will provide a replacement in exchange for the
defective product.
In order to obtain service under this warranty, Customer must notify Tektronix of the defect before the expiration of the
warranty period and make suitable arrangements for the performance of service. Customer shall be responsible for
packaging and shipping the defective product to the service center designated by T ektronix, with shipping charges prepaid.
T ektronix shall pay for the return of the product to Customer if the shipment is to a location within the country in which the
T ektronix service center is located. Customer shall be responsible for paying all shipping charges, duties, taxes, and any
other charges for products returned to any other locations.
This warranty shall not apply to any defect, failure or damage caused by improper use or improper or inadequate
maintenance and care. T ektronix shall not be obligated to furnish service under this warranty a) to repair damage resulting
from attempts by personnel other than T ektronix representatives to install, repair or service the product; b) to repair
damage resulting from improper use or connection to incompatible equipment; or c) to service a product that has been
modified or integrated with other products when the effect of such modification or integration increases the time or
difficulty of servicing the product.
THIS WARRANTY IS GIVEN BY TEKTRONIX WITH RESPECT TO THIS PRODUCT IN LIEU OF ANY
OTHER WARRANTIES, EXPRESSED OR IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY
IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
TEKTRONIX’ RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND
EXCLUSIVE REMEDY PROVIDED TO THE CUST OMER FOR BREACH OF THIS WARRANTY. TEKTRONIX
AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT , SPECIAL, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS
ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES.
Contacting Tektronix
Product
Support
Service
Support
For other
information
To write us Tektronix, Inc.
For application-oriented questions about a Tektronix measurement product, call toll free in North America:
1-800-TEK-WIDE (1-800-835-9433 ext. 2400)
6:00 a.m. – 5:00 p.m. Pacific time
Or contact us by e-mail:
tm_app_supp@tek.com
For product support outside of North America, contact your
local Tektronix distributor or sales office.
Contact your local Tektronix distributor or sales office. Or visit
our web site for a listing of worldwide service locations.
http://www.tek.com
In North America:
1-800-TEK-WIDE (1-800-835-9433)
An operator will direct your call.
P.O. Box 1000
Wilsonville, OR 97070-1000
VX4237 Digital Multimeter Module User Manual
VX4237 Digital Multimeter Module User Manual
Table of Contents
Getting Started
Operating Basics
General Safety Summary iii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Safety Summary v. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preface vii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conventions vii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Related Publications vii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Product Description 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accessories 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Controls And Indicators 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuration 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation Checklist 1–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Check 1–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Overview 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Status 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power-on 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Instrument I/O – VXIbus Basics 2–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Low Level Interface 2–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Trigger Combinations 2–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Syntax and Commands
Status and Events
Command Syntax 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Command Groups 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SCPI Commands 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Native Language Commands 3–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IEEE-488.2 Common Commands 3–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SCPI Commands 3–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Native Language Commands 3–69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IEEE 488.2 Common Commands 3–97. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Message Exchange 4–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Retrieval of Device Status Information 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standard-Defined Features 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VX4237 Status Reporting – Detail 4–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SCPI Additional Status Reporting 4–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SCPI Error Codes and Messages 4–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Device-Dependent Error Messages 4–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VX4237 Digital Multimeter Module User Manual
i
Table of Contents
Appendices
Glossary
Appendix A: Specifications A–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix B: Rear-Panel Connections B–1. . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix C: *RST Condition C–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix D: Performance Verification D–1. . . . . . . . . . . . . . . . . . . . . . . . .
User Uncertainty Calculations D–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using the Verification Work Sheets D–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preparation D–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DC Voltage Check D–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AC Voltage Check D–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AC Linearity Check D–8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Resistance Check D–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix E: User Service E–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
User-Replaceable Parts E–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjustment E–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjustment Procedure E–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ii
VX4237 Digital Multimeter Module User Manual
General Safety Summary
Review the following safety precautions to avoid injury and prevent damage to
this product or any products connected to it. To avoid potential hazards, use this
product only as specified.
Only qualified personnel should perform service procedures.
While using this product, you may need to access other parts of the system. Read
the General Safety Summary in other system manuals for warnings and cautions
related to operating the system.
To Avoid Fire or
Personal Injury
Connect and Disconnect Properly . Do not connect or disconnect probes or test
leads while they are connected to a voltage source.
Ground the Product. This product is indirectly grounded through the grounding
conductor of the mainframe power cord. To avoid electric shock, the grounding
conductor must be connected to earth ground. Before making connections to the
input or output terminals of the product, ensure that the product is properly
grounded.
Observe All Terminal Ratings. To avoid fire or shock hazard, observe all ratings
and markings on the product. Consult the product manual for further ratings
information before making connections to the product.
Do not apply a potential to any terminal, including the common terminal, that
exceeds the maximum rating of that terminal.
Do Not Operate Without Covers. Do not operate this product with covers or panels
removed.
Use Proper Fuse. Use only the fuse type and rating specified for this product.
Avoid Exposed Circuitry. Do not touch exposed connections and components
when power is present.
Do Not Operate With Suspected Failures. If you suspect there is damage to this
product, have it inspected by qualified service personnel.
Do Not Operate in Wet/Damp Conditions.
Do Not Operate in an Explosive Atmosphere.
Keep Product Surfaces Clean and Dry .
Provide Proper Ventilation. Refer to the manual’s installation instructions for
details on installing the product so it has proper ventilation.
Symbols and Terms
VX4237 Digital Multimeter Module User Manual
T erms in this Manual. These terms may appear in this manual:
iii
General Safety Summary
WARNING. Warning statements identify conditions or practices that could result
in injury or loss of life.
CAUTION. Caution statements identify conditions or practices that could result in
damage to this product or other property.
T erms on the Product. These terms may appear on the product:
DANGER indicates an injury hazard immediately accessible as you read the
marking.
WARNING indicates an injury hazard not immediately accessible as you read the
marking.
CAUTION indicates a hazard to property including the product.
Symbols on the Product. The following symbols may appear on the product:
WARNING
High Voltage
Protective Ground
(Earth) T erminal
CAUTION
Refer to Manual
Double
Insulated
iv
VX4237 Digital Multimeter Module User Manual
Service Safety Summary
Only qualified personnel should perform service procedures. Read this Service
Safety Summary and the General Safety Summary before performing any service
procedures.
Do Not Service Alone. Do not perform internal service or adjustments of this
product unless another person capable of rendering first aid and resuscitation is
present.
Disconnect Power. To avoid electric shock, disconnect the mains power by means
of the power cord or, if provided, the power switch.
Use Care When Servicing With Power On. Dangerous voltages or currents may
exist in this product. Disconnect power, remove battery (if applicable), and
disconnect test leads before removing protective panels, soldering, or replacing
components.
To avoid electric shock, do not touch exposed connections.
VX4237 Digital Multimeter Module User Manual
v
Service Safety Summary
vi
VX4237 Digital Multimeter Module User Manual
Preface
Conventions
This is the user manual for the VX4237 Digital Multimeter Module.
Please read and follow all instructions for installation and configuration. Use the
Installation Checklist to insure proper installation, and as a record of initial
settings.
This manual assumes you are familiar with VXIbus instruments and operation,
and with the purpose and function of this instrument. The Operating Basics
section gives a summary of VXIbus operation, and presents an overview of this
instrument’s operation.
The Syntax and Commands section has a summary of all the commands, and
detailed descriptions of each command.
The names of all switches, controls, and indicators appear in this manual exactly
as they appear on the instrument.
Related Publications
Specific conventions for programming are given in the section Syntax and
Commands.
This manual uses the following notational conventions:
H An asterisk (*) following a signal mnemonic denotes that the signal is active
when in the low state (typically, 0 V).
H A signal mnemonic without a following asterisk (*) denotes that the signal is
active when in the high state (typically, 2.8 – 5 V).
Regarding the base of a number:
H Unless otherwise noted, all numbers are assumed to be decimal (base 10).
The following documents on related subjects may be useful in making efficient
use of the module:
VXIbus System Specification, Version 1.4
ANSI/IEEE Std. 1014–1987, IEEE Standard for a Versatile Backplane Bus: VME
Bus
VX4237 Digital Multimeter Module User Manual
vii
Preface
viii
VX4237 Digital Multimeter Module User Manual
Getting Started
Getting Started
Product Description
The VX4237 Digital Multimeter Module is a printed circuit board assembly for
use in a mainframe conforming to the VXIbus Specification. The VX4237 is a
fully compatible VXIbus C-size Digital Multimeter (DMM) that has the
following measurement capabilities and features:
H Five DC voltage ranges from 200 mV – 300 V with 100 nV resolution
H Five AC voltage ranges from 200 mV – 300 V with 1 V resolution
H Six resistance ranges from 200 – 20 M with 100 resolution
H AC and DC current 1000 mA range
H Selectable 4.5 – 6.5 digit resolution
H External trigger with delay
H Programmable external calibration
The VX4237 is a message-based device using A16 addressing.
BITE (Built-In Test
Accessories
Equipment)
Standard
Optional
Built In Test Equipment is provided by extensive self tests that are automatically
invoked on power-up, and may also be invoked on command. Circuitry tested
includes the CPU and all memory, and the DMM circuitry. The front panel LEDs
provide visual BITE for module operation.
Standard accessories to the VX4237 are the VX4237 Digital Multimeter User
Manual and Reference Manual.
An optional input lead (for the 15-pin front panel connector) is available from
Tektronix by ordering part number 012-1391-00.
VX4237 Digital Multimeter Module User Manual
1–1
Getting Started
Top Cover
Controls And Indicators
Switches
Front
Panel
Logical Address Switch Access
LSB MSB
0
1
Figure 1–1: VX4237 Controls and Indicators
The following controls and indicators are provided to select and display the
functions of the VX4237 Module’s operating environment. See Figures 1 and 2
for their physical locations.
The Local Address switch must be correctly set to insure proper operation. See
Configuration for details of how to set the switches.
1–2
LEDs
The following LEDs are visible at the top of the VX4237 Module’s front panel to
indicate the status of the module’s operation. See Operating Basics for a
description of each LED’s meaning.
Fail LED
Ready LED
Trig LED
VX4237 Digital Multimeter Module User Manual
Getting Started
Configuration
Logical Address Switch
Figure 1–2: VX4237 Front Panel
The Logical Address Switch must be correctly set to insure proper operation.
Refer to Figure 1–1 for the physical location.
Each function module in a VXIbus System must be assigned a unique logical
address, from 1 to 255 decimal. The base VMEbus address of the VX4237 is set
to a value between 1 and 255 by an 8-way DIL switch, accessible through a hole
in the top cover.
VX4237 Digital Multimeter Module User Manual
1–3
Getting Started
Figure 1–3: Logical Address Switch Set To Logical Address 6
The switch contacts are labelled 1 through 8, corresponding to the eight bits of
the logical address value (8 MSB; 1 LSB). One side of the switch bank is
labelled OPEN; this represents address bits at logic 1. Setting a switch to the
CLOSED position sets its address bit to logic 0.
The address can be set to any value between 1 and 255 (address 0 is reserved for
the Resource Manager).
The VX4237 fully supports Dynamic Configuration as defined in Section F of
the VXI Specification. Address 255 should be selected only if the Resource
Manager also supports Dynamic Configuration.
Line Frequency
Backplane Jumpers
IEEE-488 Address. Using the VX4237 Module in an IEEE-488 environment
requires knowing the module’s IEEE-488 address in order to program it.
Different manufacturers of IEEE-488 interface devices may have different
algorithms for equating a logical address with an IEEE-488 address. Consult the
operating manual of the IEEE-488 Interface Module being used.
Using the LINE command, you can set the VX4237 for best accuracy by
matching it to the specific line frequency used in your application. Refer to the
Native Command Language sub-section for further information.
NOTE. The following instructions pertain to Tektronix Mainframes. If you are
installing the DMM in a different mainframe, refer to the Instruction Manual for
that mainframe for the correct jumper strap numbers.
VXIbus mainframes contain daisy-chain jumper straps for the Bus Grant (BG0 –
BG3) and Interrupt Acknowledge (IACK) signals. Tektronix Mainframes are
shipped with all jumpers installed. All jumper straps must be removed for slots
that have cards installed.
1–4
VX4237 Digital Multimeter Module User Manual
Getting Started
NOTE. If you are using a Tektronix Mainframe, the names of the jumper straps
(BG0 through BG3 IACK) are printed on the circuit board facing the front of the
mainframe. These jumpers are accessed from the front of the mainframe.
Remove all jumper straps to the immediate left of the slot in which the DMM
will be installed. Retain the straps for possible future reconfiguration.
Bus Grant Jumper Straps
Slot
1 J101 1 J1012 J1013 J1014
2 J1021 J1022 J1023 J1024
3 J1026 J1027 J1028 J1029
4 J1031 J1032 J1033 J1034
5 J1036 J1037 J1038 J1039
6 J1041 J1042 J1043 J1044
7 J1046 J1047 J1048 J1049
8 J1051 J1052 J1053 J1054
9 J1056 J1057 J1058 J1059
10 J1061 J1062 J1063 J1064
11 J1066 J1067 J1068 J1069
12 J1071 J1072 J1073 J1074
Interrupt Acknowledge Jumper Straps
Slot
0 J2010 6 J2040
BG0 BG1 BG2 BG3
IACK Connector Slot IACK Connector
1 J2015 7 J2045
2 J2020 8 J2050
9 J2055 10 J2060
3 J2025 11 J2065
4 J2030 12 J2070
5 J2035
VX4237 Digital Multimeter Module User Manual
1–5
Getting Started
Front Panel Connectors
There are two front panel connectors: a coaxial BNC external trigger input, and a
D-type 15-pin analog input. The pinout for the analog input is shown in
Figure 1–4.
J351 Analog Input Plug
Pin layout and configuration
1
9
Hi
I+
Lo
I–
Guard
15
8
Figure 1–4: Analog Input Connector
Installation
Requirements and
Cautions
The VX4237 Module is a C size VXIbus instrument module and therefore may
be installed in any C or D size VXIbus mainframe slot other than slot 0. If the
module is being installed in a D size mainframe, consult the operating manual
for the mainframe to determine how to install the module in that particular
mainframe. Setting the module’s Logical Address switch defines the module’s
programming address. Refer to Configuration for information on selecting and
setting the module’s logical address. To avoid confusion, it is recommended that
the slot number and the logical address be the same.
A slotted screwdriver is required for proper installation.
WARNING. To avoid electric shock, tighten the module mounting screws after
installing the module into the mainframe to ensure that the front panel is
properly grounded.
1–6
VX4237 Digital Multimeter Module User Manual
Getting Started
NOTE. There are two printed ejector handles on the card. To avoid installing the
card incorrectly, make sure the ejector marked “VX4237” is at the top.
In order to maintain proper mainframe cooling, unused mainframe slots must be
covered with the blank front panels supplied with the mainframe.
Based on the number of instrument modules ordered with a Tektronix mainframe, blank front panels are supplied to cover all unused slots. Additional
VXIbus C size single-slot and C size double-slot blank front panels can be
ordered from your Tektronix supplier.
NOTE. Verify that the mainframe is able to provide adequate cooling and power
with this module installed. Refer to the mainframe Operating Manual for
instructions.
If the VX4237 is used in a Tektronix Mainframe, all VX4237 cooling requirements will be met.
Installation Procedure
NOTE. If the VX4237 Module is inserted in a slot with any empty slots to the left
of the module, the VME daisy-chain jumpers must be installed on the backplane
in order for the VXI Module to operate properly. Check the manual of the
mainframe being used for jumpering instructions.
CAUTION. The VX4237 Module is a piece of electronic equipment and therefore
has some susceptibility to electrostatic damage (ESD). ESD precautions must be
taken whenever the module is handled.
1. Record the revision level, serial number (located on the label on the top
shield of the VX4237), and switch settings on the Installation Checklist.
2. Verify that the switches are switched to the correct values.
3. Make sure power is off in the mainframe.
4. The module can now be inserted into one of the instrument slots of the
mainframe.
5. Cable Installation: Use the correct cable to interface between the module I/O
connector and the Unit Under Test (UUT). The recommended cable is listed
in Specifications.
VX4237 Digital Multimeter Module User Manual
1–7
Getting Started
Installation Checklist
Installation parameters will vary depending on the mainframe being used. Be
sure to consult the mainframe Operating Manual before installing and operating
the module.
Revision Level:
Serial No.:
Mainframe Slot Number:
Switch Settings:
VXIbus Logical Address Switch:
(FFh enables dynamic configuration.)
Interrupt Level Select Switch: Dynamically programmed by the Resource
Manager.
Cables Installed: (if any)
1–8
Performed by: _______________________ Date: _____________
VX4237 Digital Multimeter Module User Manual
Functional Check
Getting Started
The VX4237 Module will execute a self test at power-on, or on direction of a
VXIbus hard or soft reset condition, or on command. The power-on self test
consists of an interface self test and an instrument self test. The commanded self
test performs only the instrument self test. A VXIbus hard reset occurs when
another device, such as the VXIbus Resource Manager, asserts the backplane line
SYSRST*. A VXIbus soft reset occurs when another device, such as the
VX4237’s commander, sets the Reset bit in the VX4237’s Control register.
At power-on, as well as during self test, all module outputs remain isolated from
the module’s front panel connector.
During power-on, or a hard or soft reset, the following actions take place:
1. The SYSFAIL* (VME system-failure) line is set active, indicating that the
module is executing a self test, and the Failed LED is on. In the case of a
soft reset, SYSFAIL* is set. However, all Tektronix/CDS commanders will
simultaneously set SYSFAIL INHIBIT. This is done to prevent the resource
manager from prematurely reporting the failure of a card.
2. On completion of the interface self test, SYSFAIL* is de-asserted. If the test
fails, the SYSFAIL* line remains active. If the interface self test passed, the
SYSFAIL* line is released, and the module enters the VXIbus PASSED state
(ready for normal operation). If it failed, the module enters the VXIbus
FAILED state.
3. The instrument self test, as described in the IEEE 488.2 *TST? command, is
then executed. If the self test fails, the module makes an internal record of
what failure(s) occurred.
The default condition of the VX4237 Module after the completion of power-on
self test is as follows:
DC voltage mode
300 V range
6.5 digit resolution
filter OFF
INPUT OFF (no input on either channel)
GUARD LCL (4-wire connection internal grounding)
TSRCE SYS (internal trigger source)
DELAY DFLT (default time delays)
Self test can also be run at any time during normal operation by using the *TST?
command. At the end of a self test initiated by this command, the module is
restored to its pre-test state.
During a commanded self test:
H SYSFAIL* is not asserted.
VX4237 Digital Multimeter Module User Manual
1–9
Getting Started
H The module executes the same instrument self test as in the power-on case.
H When the self test is completed, the module sets itself to the power-on state.
SYSFAIL* Operation
SYSFAIL* becomes active during power-on, hard or soft reset, self test, or if the
module loses any of its power voltages. When the mainframe Resource Manager
detects SYSFAIL* set, it will attempt to inhibit the line. This will cause the
VX4237 Module to deactivate SYSFAIL* in all cases except when +5 V power
is lost.
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VX4237 Digital Multimeter Module User Manual
Operating Basics
Operating Basics
Functional Overview
The VX4237 Module is programmed by ASCII characters issued from the
system controller to the VX4237 Module via the module’s VXIbus commander
and the VXIbus mainframe backplane. The module is a VXIbus Message Based
Device and communicates using the VXIbus Word Serial Protocol. Refer to the
manual for the VXIbus device that will be the VX4237 Module’s commander for
details on the operation of that device.
If the module’s commander is a Tektronix/CDS Resource Manager/IEEE-488
Interface Module, refer to that Operating Manual and the programming examples
in this manual for information on how the system controller communicates with
the commander being used.
The VX4237 is a fully compatible VXIbus C-size Digital Multimeter (DMM)
that has the following measurement capabilities and features:
H Five DC voltage ranges from 200 mV – 300 V with 100 nV resolution
H Five AC voltage ranges from 200 mV – 300 V with 1 V resolution
Operating Status
Ready LED
Fail LED
H Six resistance ranges from 200 – 20 M with 100 resolution
H Selectable 4.5 – 6.5 digit resolution
H External trigger with delay
H Programmable external calibration
You can determine the module’s current operating status from the LEDs on the
front panel.
This green LED is normally on and is off if the +5 V power supply fails or if the
+5 V fuse blows.
This normally off red LED is on whenever SYSFAIL* is asserted, indicating a
module failure. Module failures include failure to correctly complete an interface
self test, loss of a power rail, or failure of the module’s central processor.
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Operating Basics
If the module loses any of its power voltages, the Failed LED will go on and
SYSFAIL* will be asserted. A module power failure is indicated when the
module’s Ready LED is extinguished.
Trig LED
The TRIG light is turned on when the VX4237 is triggered to make a measurement.
Power-on
The VX4237 Module will complete its self test and be ready for programming
five seconds after power-on. The VXIbus Resource Manager may add an
additional one or two second delay. The Power LED will be on, and all other
LEDs off. The MSG LED will blink during the power-on sequence as the
VXIbus Resource Manager addresses all modules in the mainframe. The default
condition of the module after power-on is described in Functional Check.
When power is applied to the VX4237, all functions are forced to a safety default
state. Once a function is configured to a desired state, it remains in that state
until changed or the power is removed.
The *LRN? command can be used to query the VX4237 for its current settings.
More information on this command is provided in the Command Description
sub-section.
Instrument I/O – VXIbus Basics
2–2
NOTE. If the user’s mainframe has other manufacturer’s computer boards
operating in the role of VXIbus foreign devices, the assertion of BERR* (as
defined by the VXIbus Specification) may cause operating problems on these
boards.
The VX4237 Module is a C size single slot VXIbus Message-Based Word Serial
instrument. It uses the A16, D16 VME interface available on the backplane P1
connector and does not require any A24 or A32 address space. The module is a
D16 interrupter.
The VX4237 Module is neither a VXIbus commander or VMEbus master, and
therefore it does not have a VXIbus Signal register. The VX4237 is a VXIbus
message based servant.
The module supports the Normal Transfer Mode of the VXIbus, using the Write
Ready, Read Ready, Data In Ready (DIR), and Data Out Ready (DOR) bits of
the module’s Response register.
VX4237 Digital Multimeter Module User Manual
Operating Basics
A Normal Transfer Mode read of the VX4237 Module proceeds as follows:
1. The commander reads the VX4237’s Response register and checks if the
Write Ready and DOR bits are true. IF they are, the commander proceeds to
the next step. If not, the commander continues to poll these bits until they
become true.
2. The commander writes the Byte Request command (0DEFFh) to the
VX4237’s Data Low register.
3. The commander reads the VX4237’s Response register and checks if the
Read Ready and DOR bits are true. If they are, the commander proceeds to
the next step. If not, the commander continues to poll these bits until they
become true.
4. The commander reads the VX4237’s Data Low register.
A Normal Transfer Mode Write to the VX4237 Module proceeds as follows:
1. The commander reads the VX4237’s Response register and checks if the
Write Ready and DIR bits are true. If they are, the commander proceeds to
the next step. If not, the commander continues to poll the Write Ready and
DIR bits until they are true.
VX4237 Configuration
Registers
2. The commander writes the Byte Available command which contains the data
(0BCXX or 0BDXX, depending on the End bit) to the VX4237’s Data Low
register.
Below is a list of the VX4237 Configuration registers with a complete description of each. In this list, RO = Read Only, WO = Write Only, R = Read, and W =
Write. The offset is relative to the module’s base address:
T able 2–1: Register Definitions
Register Address Type Value (Bits 15–0)
ID Register 0000H RO 101 1 1111 1111 1100 (BFFCh)
Device Type 0002H RO See Device Type definition below
Status 0004H R Defined by state of interface
Control 0004H W Defined by state of interface
Offset 0006H W Not used
Protocol 0008H RO 1111 0111 1111 1111 (F7FFh)
Response 000AH RO Defined by state of the interface
Data High 000CH Not used
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Operating Basics
T able 2–1: Register Definitions (Cont.)
Register Value (Bits 15–0)TypeAddress
Data Low 000EH W Command-dependent
Data Low 000EH R Command-dependent
Register Bit Definitions
ID: BFFCh
Device:
Protocol: F7FFh
VXI WSC and Effects
*RST and Effects
Reset
The VXI Word Serial ‘clear’ Message will force the following instrument states:
H The input buffer and output queue are cleared.
H Parser is reset to the beginning of a message.
H Any device-dependent message interlocks are cleared.
This command will not:
H Change any settings or stored data within the instrument except as listed
above.
H Interrupt analog input.
H Interrupt or affect any functions of the device.
H Change the status byte.
The effects of the *RST command are described in Appendix C.
A complete instrument reset is accomplished by the two reset commands in
sequence. In other circumstances they may be used individually:
2–4
WS clear Message exchange initialization
*RST Device initialization
VX4237 Digital Multimeter Module User Manual
Low Level Interface
Operating Basics
This section describes the low-level VXI interface.
VXI-to-DMM
Communications Cycle
Word Serial Protocol
This section outlines the sequence of events that may take place between the
DMM and its VXI commander. The main low-level communication is the VXI
Word Serial Protocol, which is a simple handshake system. For example:
If the DMM indicated with a flag that it was ready to receive, the commander
writes a word and sets a flag indicating that data is available. The DMM reads
the word and clears its flag.
To get data from the DMM, the commander asks for a byte using the same
sequence as previously explained. It then waits for the DMM to set a flag
indicating that the DMM has placed a word in the Output Register. When this
flag goes true, the commander reads the data. This read clears the flag, allowing
the cycle to repeat.
In addition to the Word Serial Protocol, there is an Interrupt Protocol that can be
used. For further explanation of the registers used in VXI communications, refer
to the VXIbus Specification, Version 1.3, July 14, 1989.
Following is a more detailed explanation of the low-level communications
sequences that can take place between the DMM and its commander. For the
following descriptions, assume that all power-up sequences have been completed
and that the DMM is in a quiescent state awaiting a command. There are three
possible interactions: data sent from the commander to the DMM, data sent from
the DMM to the commander, and the DMM generated interrupt cycle.
Data is sent from the Commander to the DMM with the following steps:
1. The commander waits for the DMM to set the Write Ready bit in the VXI
Response Register. (This bit indicates that the DMM is ready for data.)
2. The commander writes a word of data into the Data Low Register of the
DMM. The write action clears the Write Ready bit in the DMM. The write
also generates an internal interrupt to inform the DMM that data has arrived.
3. The DMM reads the data from the Data Low Register and parses the data
word to see which VXI Word Serial Command the high order byte contains.
The parser then acts on this command. If the low byte of the word contains
data, this will be passed on to the high level command parser.
4. When the data word has been processed, the DMM can again set the Write
Ready bit to indicate that it is ready for another exchange.
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Operating Basics
Data is sent from the DMM to the Commander with the following steps:
1. The commander can only obtain a word of data from the DMM by request-
ing it. This request comes in the form of a Word Serial Protocol Byte
Request command. The commander must send a word of data that is the
Byte Request command using the previously described sequence before it
can gain a response.
2. On receiving the Byte Request command, the DMM gets a word of data
from the output buffer and places it in the Data Low Register. The action of
writing the data into the register sets the Read Ready bit in the DMM VXI
Response Register.
3. If the DMM is set to interrupt the commander, it will do so at this time.
(Refer to the following discussion of The Interrupt Cycle.)
4. Either in response to an interrupt, or by polling, the commander will become
aware of the setting of the DMM Read Ready bit. The commander then reads
the word of data from the DMM Data Low Register. The read action clears
the DMM Read Ready bit.
The Interrupt Cycle
5. This completes the transfer of data. To obtain another word of data from the
DMM, the commander must send another Byte Request command.
The VXI Specifications allow for two type of interrupt cycles: response or event.
The two types are mutually exclusive and have to be selected by the controller
before they become active.
1. The commander uses several Word Serial Protocol commands to select
when, how, and with what the DMM will interrupt. The “when” could be on
any of the Read Ready, Write Ready, or ERR* bits going true. The “how” is
selected from the VME interrupt levels (IRQ1* <197> IRQ7*). The “with
what” can be either a Response Interrupt or an Event Interrupt.
2. When the condition for the DMM to interrupt the controller occurs, the
DMM initiates the interrupt cycle. For example, directly after the DMM has
placed a word of data in the Data Low Register for the commander to read.
3. In the case of a Response Interrupt, the commander responds with the VME
interrupt acknowledge cycle. The DMM returns a vector consisting of the
logical address (on the low byte) and the upper half of the Response Register
(on the high byte).
4. In the case of an Event Interrupt, the DMM places the contents of the Event
Register in the high byte of the vector (instead of the upper half of the
Response Register).
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Operating Basics
T rigger Combinations
The table below outlines how the various triggers and trigger sources interrelate.
Type/Mode IMM Bus Hold EXT TTL
3
READ?
3
MEAS?
TRIG:IMM
TTL No error,
EXT No error,
GET –211,
S TRG –21 1,
INIT
1
2
3
2
1
TRIG:IMM will give an error or –211, Trigger ignored if an INIT has not been received first.
If source is IMM, then an INIT will cause a measurement to be taken, putting the dmm back to IDLE state. Thus the
TRIG:IMM command will always generate the –211, Trigger ignored error.
If the DMM is in block mode, eg. TRIG:COUNt 5, then READ?/MEAS? will take 5 measurements in the TRIG: SOURce IMM
mode. However, if TRIG:SOURCe EXT|TTL is selected, then five individual trigger pulses must be supplied before an
answer is returned.
1 reading taken
and returned
1 reading taken
and returned
–21 1,
‘Trigger ignored.’
trigger ignored.
trigger ignored.
‘Trigger ignored.’
‘Trigger ignored.’
1 reading taken
and stored.
–214,
‘Trigger deadlock’
–214,
‘Trigger deadlock’
1 reading taken
and stored.
No error,
trigger ignored.
No error,
trigger ignored.
1 reading taken
and stored.
1 reading taken
and stored.
Enables this mode Enables this mode Enables this mode Enables this mode
–213,
‘lnit ignored’
–213,
‘lnit ignored’
1 reading taken
and stored.
No error,
trigger ignored.
No error,
trigger ignored.
–21 1,
‘Trigger ignored.’
–21 1,
‘Trigger ignored.’
Holds bus until
trigger occurs,
then returns result.
Holds bus until
trigger occurs,
then returns result.
1 reading taken
and stored.
No error,
trigger ignored.
1 reading taken
and stored.
–21 1,
‘Trigger ignored.
–21 1,
‘Trigger ignored.’
Holds bus until
trigger occurs,
then returns result.
Holds bus until
trigger occurs,
then returns result.
1 reading taken
and stored.
1 reading taken
and stored.
No error
trigger ignored.
–21 1,
‘Trigger ignored.’
–21 1,
‘Trigger ignored.’
Also note that if in the TRIG:SOURce EXT | TTLn mode with a
READ?/MEAS? command, it is not possible to send any further commands to
the DMM as it is waiting for the triggers to arrive so it can respond with the data
to the query. The only way out of this is by all of the triggers arriving or a device
clear.
Certain trigger modes will hold the Bus as defined under SCPI version 1991.0.
The VX4237 will respond to external trigger pulses from either front panel BNC
socket or VXI backplane trigger bus. Measurement complete triggers can only be
generated on the VXI backplane.
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Operating Basics
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VX4237 Digital Multimeter Module User Manual
Syntax and Commands
Command Syntax
Commands follow the conventions established by the March 1987 Draft IEEE
Standard 488.2, Codes, Formats, Protocols, and Common Commands. Command protocol and syntax for the VX4237 Module are as follows:
< > Delimits a required user-defined argument, element, or parameter.
[ ] Delimits an optional argument, element, or parameter.
{ } Delimits groups in which at least one argument, element, or parameter must
be selected.
| Delimits exclusive-OR selectable arguments, elements, or parameters.
::= Means ‘is defined as’.
[ ]* Indicates that an argument, element, or parameter may be repeated zero or
more times.
; (semicolon) Is a message unit separator, and is used to separate parts of multiple
commands.
: (colon) Is a compound header separator, and is used to separate multiple header
mnemonics in a compound command.
, (comma) Delimits command elements.
Case
Program Data Formats
Decimal Numeric Program
Data
VX4237 Command Set NRf
Format
Command elements printed in upper-case letters are predefined command words;
and command elements printed in lower-case letters are user-defined words.
Program data message formats for the instrument include: decimal numeric,
ASCII string, and arbitrary block.
The decimal numeric program data types and formats are as follows:
<NR1>, Implicit point (integer), 1, +3, –2, +10, –20
<NR2>, Explicit point, unscaled (fixed point), 1.2, +2.3, –5.1
<NR3>, Explicit point, scaled (floating point), 1E+2, +3.36E–2, –1.02E+3
NRf means any format (NR1, NR2, or NR3) is acceptable.
VX4237 Digital Multimeter Module User Manual
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Command Syntax
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VX4237 Digital Multimeter Module User Manual
Functional Command Groups
The VX4237 will power-up default in SCPI language but has the ability to
switch to Native (IEEE-488.2) language. Both languages obey IEEE-488.2
command syntax.
IEEE 488.2 defines sets of Mandatory Common Commands and Optional
Common Commands along with a method of Standard Status Reporting. The
VX4237 implementation of SCPI language conforms with all IEEE-488.2
Mandatory Commands but not all Optional Commands. It conforms with the
SCPI-approved Status Reporting method.
This section summarizes the SCPI and Native (IEEE-488.2) language commands
for the VX4237.
SCPI Commands
The following table shows SCPI Command and Queries supported by the
VX4237.
Command Format Description
ABORt Abort current trigger state and return to idle state.
CALibration
:HIGH? [<numeric_value>] Perform full scale calibration using the <numeric_value>.
:LOW? [<numeric_value>] Performs zero scale calibration using the <numeric>.
:SECure <Boolean> Enable the calibration security.
:SECure? Query the current setting of the security.
:SLFRequency? Store current line frequency in non-volatile stores.
CONFigure<function> <function> General configuration command.
<parameter> <source_list>
<parameter>[,<source_list>]
:CURRent[:DC}|:AC Selects Current; respectively DC or AC
:FRESistance Selects four wire Ohms.
:RESistance Selects two wire Ohms.
:VOL Tage[:DC]I :AC Selects Voltage; respectively DC or AC.
[<expected_value[, <resolution]]
[1,(@I )]1(@2)|(@1,2)1(@1:2)]
Parameters for the <function>.
This selects channel (if option fitted) to be measured.
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Functional Command Groups
Command Format Description
CONFigure? This returns the current selected function, range and resolution of the
DMM.
FETCh? Returns the last set of measurements taken.
INITiate
[:iMMediate] Places DMM in the wait for trigger state.
INPut
:COUPling AC|DC Selects input coupling source.
:COUPling? Queries the state of the input coupling.
:FIL Ter[:LPASs][:STATe]<Boolean> Selects or Deselects the input filter.
:FIL Ter[:LPASs][:STATe]? Query the state of the input filter.
GUARd LOW I FLOat Connect the guard to signal low, or allow the guard to float.
GUARd? Query the status of the guard connection.
[:ST ATe]<Boolean> Selects input connection or isolation.
[:ST ATe]? Queries the state of the input connection.
ZERO? Performs an input zero offset correction.
MEASure Configure the DMM and take a measurement and INITiates that
measurement.
<function>
<parameter> <source_list>
<function> ? <parameters>[, <source_list> ]
:CURRent[[:DC]I :AC]? Selects Current, either DC or AC
:FRESistance Selects four wire Ohms.
:RESistance Selects two wire Ohms.
:VOL Tage[[:DC]I :AC]? Selects voltage, either DC or AC
[<expected_value[, <resolution]]
[[,(@1 )]1(@2)1(@1,2)1(@1:2)]
OUTput
:TTL Trg0[1121314151617 :PROTocol SYNChronous
IASYNchronous
:TTL Trg01112|314151617 :PROT ocol ? Query the VXI lines protocol.
READ? Places the DMM in a wait for trigger state and then returns the
Parameters for the <function>.
This selects channel (if option fitted) to be measured.
Set the VXI trigger line protocol mode.
measurement after the trigger.
[SENSe:]
CURRent[:DC] I :AC <parameter> Selects either DC or AC current.
CURRent[:DC] I :AC <parameter>? Query the setting current function setting.
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VX4237 Digital Multimeter Module User Manual
Functional Command Groups
Command Format Description
RESistance I :FRESistance <parameter> Selects either 2 or 4 wire resistance measurement.
RESistance I :FRESistance <parameter>? Query the setting resistance setting.
VOL Tage[:DC]I :AC <parameter> Selects either DC or AC Voltage.
VOL Tage[:DC]I :AC <parameter>? Query voltage setting.
<parameter>
:RANGe<numeric_value> Selects the value expected to be measured.
:AUTO<Boolean> Selects Autorange.
:RESolution<numeric value> Selects the resolution for the function selected.
MAXimum Selects the maximum resolution for the function selected.
:MINimum Selects the minimum resolution for the function selected.
:AUTO ON Explicitly setting a value for RESolution will turn Auto:Off.
FIL Ter{:LPASs][:STATe] <Boolean> Selects or deselects the input filter.
FIL Ter[:LPASs][:STATe]? Query the state of the input filter.
LFRequency<numeric_value> Set the integration time related to line frequency setting.
LFRequency? Query the line frequency setting.
ST ATus
:OPERation :CON Dition ? Queries the operational condition register.
:OPERation[:EVENt]? Queries the operation event register.
:OPERation:ENABle<Nrf> Sets conditions in the operation status register.
:OPERation:ENABle? Queries set conditions in operation status register.
:QUEStionable:CONDition? Queries the questionable condition register.
:QU EStionable:[ :EVENt] ? Queries the questionable event register.
:QUEStionable:ENABle<NRf> Sets conditions in questionable status enable register.
:QUEStionable:ENABle? Queries set conditions in questionable status register.
:PRESet Resets the state of the STATus register.
SYSTem
:ERRor? Query the next error in the error queue.
LANguage NAT ive Causes DMM to switch to another command interpreter.
:VERSion? Returns the version of SCPI to which the instrument conforms.
TEST
[:ALL]? Performs complete self test.
:TYPE?<Nrf> Performs a specific numbered test.
TRIGger
[:IMMediate] Trigger the DMM immediately
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Functional Command Groups
Command Format Description
:COUNt <numeric_value> Sets the number of triggers.
:COUNt? Query the count setting.
:DELay<numeric_value> Sets the time delay between the trigger and the measure.
:AUTO<Boolean> Selects default delay settings.
:DELay? Queries the current trigger delay.
:SOURce BUS IEXTernal|HOLD IIMMediate|TTL Trg<n>
(n = 1 to 7)
:SOURce? Query the trigger source setting.
Specify the trigger source.
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VX4237 Digital Multimeter Module User Manual
Native Language Commands
The following is an overview of the Native language commands.
Command Action
ACV Selects the AC voltage mode and sets the range, resolution, filter, and
ATOD? Recalls the A/D calibration constants.
BKNO? Queries the number of readings present in the Block Reading buffer.
BLOCK Sets the number of readings to be taken in a block.
BRCL? Recalls readings from the Block Reading buffer.
CAL Enables or disables the Calibration mode.
CALH? Performs an autocalibration at the upper end of the currently selected
CALL? Performs an autocalibration at the lower end of the currently selected
Functional Command Groups
coupling.
range.
range.
CLRM? Clears the stored calibration constants.
DCV Selects DC voltage measurement mode, and sets the range, resolution
and filter.
DDQ? Recalls the last error from the queue of device-dependent errors.
DELA Y Sets a trigger delay.
DUMP? Recalls result from the Test buffer.
GUARD Selects local (internal) or remote (external) grounding.
INPUT Enables or disables the input port.
LINE Selects the line frequency setting.
LINE? Reads the setting of the line frequency switch.
OHMS Selects the resistance measurement mode, and sets the range,
resolution, and measurement mode.
RDG? Queries the last data reading.
STOR? Recalls the calibration constants for the currently selected function and
range.
TEST? Performs an individual test from the self test list.
TSRCE Selects the trigger source.
X? Performs a system trigger and outputs the result.
ZERO? Performs an input zero.
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Functional Command Groups
IEEE-488.2 Common Commands
The following is an overview of the IEEE-488.2 Common Commands.
Command Action
*OPC Sets the Operation Complete (OPC) bit in the Event Status register
*OPC? Places a 1 in the device output queue when all pending operations
*PUD Stores data in the non-volatile memory.
*PUD? Recalls stored data from the non-volatile memory.
*RST Resets the VX4237 to the power-up state and resets all instrument
*SRE Sets the bits in the Service Request Enable register.
*SRE? Queries the setting of the bits in the Service Request Enable register.
*STB? Reads the status byte from the Service Request Enable and Event
when all pending operations have completed.
have been completed.
variables to the default values.
Status registers.
*TRG Generates a trigger pulse.
*TST? Executes self test diagnostic routines.
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VX4237 Digital Multimeter Module User Manual
SCPI Commands
ABORt
This section lists the SCPI commands supported by the VX4237 in alphabetical
order.
The ABORt command returns the DMM to the IDLE state. Any measurements
that are in progress will be completed before the DMM goes into the IDLE state.
See page 3–61, Figure 3–1.
This command does not affect the settings of the trigger system and any
subsequent INITiate will cause the DMM to return to the wait-for-trigger state as
selected by the TRIGger:SOURce command. Refer to the TRIGger subsystem,
page 3–60.
Syntax
Related Commands
Query Format
Errors
*RST Condition
Native Equivalents
(Event, No query)
No Query.
No errors associated with this command.
There is no associated *RST condition. However, after the *RST the DMM is
put in the IDLE state.
There are no native equivalent commands.
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SCPI Commands
CALibration Subsystem
This subsystem is used to calibrate the ranges and functions of the DMM. This
will correct for any system errors due to drift or ageing effects.
Before any calibration can take place, two security levels must be set. First, there
is a switch on the DMM itself that must be set to CAL ENABLE. Having done
this, the command CALibration:SECure ON must be sent.
Syntax
Related Commands
CALibration
:HIGH? [<numeric_value>]
:LOW? [<numeric_value>]
:SECure <Boolean>
:SLFRequency?
There are no directly related commands however commands to configure the
DMM such as CONFigure, SENSe etc. are used in conjunction with CALibration.
See also Routine Calibration Procedure; section 8 of this handbook.
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VX4237 Digital Multimeter Module User Manual
CALibration:HIGH? [<numeric_value>]
CALibration:LOW? [<numeric_value>]
These commands are used to perform a calibration operation. In the case of
:HIGH?, this will be at the full range value. In the case of :LOW? this will be at
zero for DC and Ohms, or at 1% of range for AC. The DMM will measure the
input signal as a reference. From this measurement, correction factors are
calculated and stored in the non-volatile memory. These correction factors will
then be applied to all subsequent readings.
If the calibration operation is a success then the command returns a 0. If the
command fails for any reason, then a 1 is returned and an error message is put in
the error queue.
Note that to use this command the calibration switch must be set to CAL
ENABLE and the command CALibration:STATe ON must have been sent.
The optional parameter <numeric_value> gives the actual value of the reference
being applied to the input terminals if this is not the nominal value.
SCPI Commands
Errors
*RST Condition
Error 110, ‘Calibration switch disabled’ will be generated if either the calibration
switch is not set to enable and the CAL:SECure ON command has not been
received.
Error 222, ‘Data out of range’ will be generated if the <numeric_value> is out of
range or the measured value is out of range compared to the <numeric_value>
If the input is not connected, or the instrument is in DC coupled AC, or
TRIG:SOURce IMM is not selected, then error 120, ‘Calibration operation
invalid’ will be reported.
If the calibration fails for any other reason, then the message 122, ‘Calibration
operation failed’ will be reported.
There is no associated *RST condition.
NOTE. Both CALibration:SECure ON and the hardware calibration switch found
on the front panel have to be enabled before calibration can take place. Four
measurements are taken for every Calibration trigger. See the CVAL? command.
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SCPI Commands
CALibration:SECure <Boolean>
This command is used to enable the calibration mode. Before this command can
be accepted, the calibration switch on the DMM must be set to CAL ENABLE.
The accepted value for <Boolean> is OFF|0|1|ON.
Errors
Query Format
*RST Condition
An error will be generated if CAL:SEC ON is received and the calibration switch
is not set to CALENABLE.
This queries the current setting of the secure mode. It returns either 0 for
disabled, or l for enabled.
3–12
VX4237 Digital Multimeter Module User Manual
CALibration:SLFRequency?
This query command is used to store the current setting of the ADC conversion
line frequency into the non-volatile calibration stores. This value will then
become the default value at power on and *RST.
The line frequency is set using the SENSe:LFRequency command.
Note that to use this command the calibration switch must be set to CAL
ENABLE and the command CALibration:STATe ON must have been sent.
SCPI Commands
Errors
Query Format
*RST Condition
Native Equivalents
An error of 110, ‘Calibration switch disabled’ will be generated if either the
calibration switch is not set to enable and the CAL:SECure ON command has
not been received.
This command is a query only and will return 0 if the value is successfully
stored, or 1 if the operation failed.
Last value set with an CAL:SLFR? command.
CALibration:SECure ≡ CALON/OFF
CALibration:HIGH <...> ≡ CALH?
CALibration:LOW <...> ≡ CALL?
CALibration:SLFRequency? ≡ STLN?
VX4237 Digital Multimeter Module User Manual
3–13
SCPI Commands
CONFigure
The CONFigure command subsystem is used to configure the DMM. It prepares
the DMM to take a measurement but does not cause a trigger.
Syntax
Related Commands
CONFigure<function> <parameters> [,<source_list>]
Subsystem:
CONFigure
Function:
:CURRent
[:DC] <parameters> [,<source_list>]
:AC <parameters> [,<source_list>]
:FRESistance <parameters> [,<source_list>]
:RESistance <parameters> [,<source_list>]
:VOLTage
[:DC] <parameters> [,<source_list>]
:AC <parameters> [,<source_list>]
Parameters:
[<expected_value> [,<resolution>]]
Source List:
[, [(@1)] | (@2) | (@1,2) | (@1:2)]
FETCh?, INITiate, INPut, MEASure?, READ? CONFigure?
3–14
Description
NOTE. INPut:STATe <Boolean> should be ON before measurement takes place.
See page 3–29 for further information on the INPut command.
The <source list> will remain in the same state after a function change.
As shown by the syntax, the command:
CONFigure<function> <parameters>[,<source_list>]
is a compound command. The <function> selects which function the DMM
measures. This may be voltage, current or resistance. Each function has
associated parameters that are used to select the range and resolution of
subsequent measurements. There is then an optional <source_list> which selects
which channel the measurement is made on.
VX4237 Digital Multimeter Module User Manual
SCPI Commands
NOTE. In the event of an error within the command, as much as possible of the
command up to the error shall be implemented. For example, if:
CONF:VOLT 1, 1E-6, (@2)
is received on a single channel DMM, then the 1 volt DC 6.5 digit range would
be selected, but the second channel selection would generate an error.
VX4237 Digital Multimeter Module User Manual
3–15
SCPI Commands
unction
Range
CONFigure:CURRent[:DC] [<expected_value>[,<resolution>]]
CONFigure:CURRent:AC [<expected_value>[,<resolution>]]
Either command selects the current measuring function. The default is for DC
current, AC can be selected with the additional parameter. AC current with a DC
component can be selected with the command:
INPut:COUPling AC|DC
See the INPut Subsystem page 3–29.
The <expected_value> is used to select the range of the function, however the
DMM has only one range: 1 Amp. Thus all values will be accepted including the
commands:
MAXimum, MINimum, AUTO, AUTO ON, AUTO OFF & DEFault
The optional <resolution> parameter is used to select the measurement resolution. There are three modes – 4.5, 5.5 and 6.5 digits. However, 6.5 digit
resolution is not allowed in AC or DC coupled AC. The tables on the left below
show the modes selected by numeric values of <resolution>, those on the fight
show the modes selected by <resolution> commands:
T able 3–1: DC Current: Numeric Values Used to Select Required
Resolutions
Required Digits
F
CURR:DC 1A <1E–6>
6.5 5.5 4.5
<1E–5>
(1.000000A)
(1.00000A)
T able 3–2: DC Current: Resolutions Selected by Command
Function <resolution> Selected Digit
CURR[:DC] MAXimum 6.5 digit
MINimum 4.5 digit
AUTO 6.5 digit
AUTO ON 6.5 digit
AUTO OFF Resolution as last set
DEFault 6.5 digit
<1E–4>
(1.0000A)
3–16
VX4237 Digital Multimeter Module User Manual
T able 3–3: AC Voltage: Numeric Values Used to Select Required
unction
Range
Resolutions
Required Digits
SCPI Commands
Errors
F
CURR:AC 1A <1E–5>
5.5 4.5
<1E–4>
(1.00000A)
(1.0000A)
T able 3–4: AC Current: Resolutions Selected by Command
Function <resolution> Selected Digit
CURR:AC MAXimum 5.5 digit
MINimum 4.5 digit
AUTO 5.5 digit
AUTO ON 5.5 digit
AUTO OFF Resolution as last set
DEFault 5.5 digit
Current is an option and if the option is not fired any CURRent command will
generate the error –241, ‘Hardware missing’.
Query Format
*RST Condition
See CONFigure? command page 3–14.
CONF:CURR:DC 1, 1E–5 (Note that this function is inactive.)
VX4237 Digital Multimeter Module User Manual
3–17
SCPI Commands
CONFigure:FRESistance[<expected_value>[,<resolution>]]
CONFigure:RESistance[<expected_value>[,<resolution>]]
These two commands are used to select the resistance measuring function.
RESistance selects two wire measurements, while FRESistance selects four wire
measurements.
The <expected_value> is used to select the range of the resistance measurement
The table shows that <expected_value> affects the range selected.
<expected_value> Range
0 to 199.9999 100
200 to 1999.999 1 k
2000 to 19999.99 10 k
20000 to 199999.9 100 k
200000 to 1999999 1 M
>2000000 10 M
MINimum 100
MAXimum 10 M
DEFault no parameter Autorange
AUTO ON Select Autorange
AUTO OFF Deselect Autorange
3–18
In the table above, DEFault, AUTO and no <expected_value> selects autoranging. In this mode the DMM will select the most appropriate range to measure the
signal on the input. Any other <expected_value> will de-select the autorange
feature. The AUTO OFF command will leave the DMM in the last active range.
The optional <resolution> parameter is used to select the measurement resolution. There are three modes – 4.5, 5.5 and 6.5 digits. The table on the left below
shows the modes selected by numeric values of <resolution>, that on the right
shows the modes selected by <resolution> commands:
VX4237 Digital Multimeter Module User Manual
SCPI Commands
unction
Range
T able 3–5: Resistance (2- and 4-Wire): Numeric Values Used to Select Required
Resolutions
Required Digits
F
RES/FRES 100 <1E–4>
1 k <1E–6>
10 k <1E–5>
100 k <1E–4>
1 M <1E–6>
10 M <1E–5>
6.5 5.5 4.5
(100.0000)
(1.000000k)
(10.00000k)
(100.0000k)
(1.000000M)
(10.00000M)
<1E–3>
(100.000)
<1E–5>
(1.00000k)
<1E–4>
(10.0000k)
<1E–3>
(100.000k)
<1E–5>
(1.00000M)
<1E–4>
(10.0000M)
<1E–2>
(100.00)
<1E–4>
(1.00000k)
<1E–3>
(10.000k)
<1E–2>
(100.00)
<1E–4>
(1.0000M)
<1E–3>
(10.000M)
T able 3–6: Resistance (2- and 4-Wire): Resolutions Selected by Command
Function <resolution> Selected Digit
RES/FRES MAXimum 6.5 digit
MINimum 4.5 digit
Errors
Query Format
*RST Condition
None
See CONFigure? command page 3–14.
(Note that this function is inactive.)
(Note that this function is inactive.)
VX4237 Digital Multimeter Module User Manual
AUTO 6.5 digit
AUTO ON 6.5 digit
AUTO OFF Resolution as last set
DEFault 6.5 digit
3–19
SCPI Commands
CONFigure:VOLTage[:DC] [<expected_value>[,<resolution>]]
CONFigure:VOLTage:AC [<expected_value>[,<resolution>]]
Either command selects the voltage measuring function. The default is DC
voltage, AC can be selected with the additional parameter. AC voltage with a DC
component can be selected with the command INPut:COUPling AC | DC.
See the INPut Subsystem.
The <expected_value> is used to select the range of the voltage measurement
The table shows how <expected_value> affects the range selected.
<expected_value> Range
0 to .1999999 100 mV
0.2 to 1.999999 1 V
2.0 to 19.99999 10 V
20.0 to 199.9999 100 V
>200 300 V
MINimum 100 mV
MAXimum 300 V
DEFault no parameter Autorange
AUTO ON Select Autorange
AUTO OFF Deselect Autorange
3–20
In the above table, DEFault, AUTO and no <expected_value> selects autoranging. In this mode the DMM will select the most appropriate range to measure the
signal on the input. Any other <expected_value> will de-select the autorange
feature. The AUTO OFF command will leave the DMM in the last active range.
The optional <resolution> parameter is used to select the measurement resolution. There are three modes – 4.5, 5.5 and 6.5 digit. However, 6.5 digit resolution
is not allowed in AC or DC coupled AC. The tables on the left below show the
modes selected by numeric values of <resolution>, those on the fight show the
modes selected by <resolution> commands:
VX4237 Digital Multimeter Module User Manual
T able 3–7: DC Voltage: Numeric Values Used to Select Required
unction
Range
unction
Range
Resolutions
Required Digits
SCPI Commands
F
VOL T:[DC] 100 mV <1E–4>
1 V <1E–6>
10 V <1E–5>
100 V <1E–4>
300 V <1E–3>
6.5 5.5 4.5
<1E–3>
(100.0000mV)
(1.000000V)
(10.00000V)
(100.0000V)
(300.000V)
(100.000mV)
<1E–5>
(1.00000V)
<1E–4>
(10.0000V)
<1E–3>
(100.000V)
<1E–2>
(300.00V)
T able 3–8: DC Voltage: Resolutions Selected by Command
Function <resolution> Selected Digit
VOL T[:DC] MAXimum 6.5 digit
MINimum 4.5 digit
AUTO 6.5 digit
AUTO ON 6.5 digit
<1E–2>
(100.00mV)
<1E–4>
(1.00000V)
<1E–3>
(10.000V)
<1E–2>
(100.00V)
<1E–1 >
(300.0V)
T able 3–9: AC Voltage: Numeric Values Used to Select Required
Resolutions
F
VOL T:AC 100 mV <1E–3>
VX4237 Digital Multimeter Module User Manual
AUTO OFF Resolution as last set
DEFault 6.5 digit
Required Digits
5.5 4.5
<1E–2>
(100.000mV)
1 V <1E–5>
(1.00000V)
10 V <1E–4>
(10.0000V)
(100.00mV)
<1E–4>
(1.00000V)
<1E–3>
(10.000V)
3–21
SCPI Commands
T able 3–9: AC Voltage: Numeric Values Used to Select Required
Resolutions (Cont.)
Required Digits
Errors
Function
RangeFunction 4.55.5Range
100 V <1E–3>
(100.000V)
300 V <1E–2>
(300.00V)
<1E–2>
(100.00V)
<1E–1 >
(300.0V)
T able 3–10: AC Voltage: Resolutions Selected by Command
Function <resolution> Selected Digit
VOL T:AC MAXimum 5.5 digit
MINimum 4.5 digit
AUTO 5.5 digit
AUTO ON 5.5 digit
AUTO OFF Resolution as last set
DEFault 5.5 digit
An error of –241, ‘Data questionable’ will be generated if greater than 6.5 digit
resolution is selected. (or >5.5 for AC).
3–22
Query Format
*RST Condition
See the CONFigure? command.
CONF:VOLT:DC 300,1E-3. This function is active.
VX4237 Digital Multimeter Module User Manual
CONFigure?
CURR1
1E–6(@1
S
1E2
<r
–6
1E4
<r
–4
1,2
1E5
1E–1
<r
–6
OL AC
10
1
1
<r e 1 –5
<r
–4
2
1,2
1E1
<r
–4
1,2
12
SCPI Commands
This queries the current configuration of the DMM. Note that it returns the
present setting of the DMM – not what was last set with a CONF command.
Syntax
Related Commands
CONFigure? (Query Only)
CONFigure, MEASure?, SENSe
This single command is used to query the current settings of the DMM, It returns
a string in the form of:
“<function><range>,<resolution>,<source_list>”
The possible combinations of the string are:
Function Range <resolution> <source_list>
}
CURR:AC 1E–5 1E–5 (@2)
1E–4 1E–4 (@1,2)
RE
FRES 1E3
ange>/1E
<range>/1E–5
ange>/1E
(@1)
(@2)
(@
)
VOLT
VOLT:AC 1E0 <range>/1E–5 (@2)
If AUTO, DEF, MIN or MAX was selected for <range> or <resolution> then the
CONF? string will contain the current setting that the DMM has selected.
VX4237 Digital Multimeter Module User Manual
1E6
1E7
E
1E2
3E2
ange>/1E
ange>/1E
ange>/1E
(@1)
(@
(@
)
)
3–23
SCPI Commands
Note that in the above the <resolution> depends on the range currently selected.
Thus if the current active selection is 10 volt, 5.5 digits, then the returned string
would be:
VOLT:DC 1E1,1E-4, (@1)
In the case of the 300 V range, then the resolution is returned as 1E–l, 1E–2 or
1E–3.
*RST Condition
Native Equivalents
Query only, no associated *RST condition.
*LRN
3–24
VX4237 Digital Multimeter Module User Manual
FETCh?
SCPI Commands
This query command retrieves the last set of measurements taken and places
them in the output queue. The returned data will be either a single reading if
‘block’ mode is not selected, or the several readings if ‘block’ mode is selected.
Syntax
Related Commands
Qualifiers
Query Format
FETCh? (Query only)
CONFigure, INITiate, READ?
Note that the SCPI definition allows <function> and <parameter> qualifiers, but
as the DMM only stores the readings for the current setting, these commands are
not implemented.
The returned data is formatted in the following character positions:
4.5 digit 1 2 3 456789101112
snxxxnnEsnnt
5.5 digit 1 2 3 45678910111213
snxxxnnnEsnnt
6.5 digit 1 2 3 4567891011121314
snxxxnnnnEsnnt
where:
s = the sign + or –
n = ASCII digit 0 to 9
x = either an n or a decimal point
E = ASCII character identifying the exponent
t = a terminator or separator: either ; or , or <lf> (linefeed character)
The measurement overload condition is reported as 200.000E+331
Multiple readings are returned with each value separated by a comma and the last
reading terminated with the linefeed character.
Errors
VX4237 Digital Multimeter Module User Manual
If no measurement has been taken or the instrument has been reconfigured, then
no result is returned and the error–230, ‘Data corrupt or stale’ is stored in the
error queue. This will be as a result of *RST, a CONE, SENSe etc command or
after an INIT command has been sent.
3–25
SCPI Commands
*RST Condition
Native Equivalents
As this is a query command then there is no associated *RST condition.
However note that *RST puts the DMM into the idle state and thus a FETCh?
command would cause an error if no INIT had been received.
RDG? BRCL?
3–26
VX4237 Digital Multimeter Module User Manual
INITiate
SCPI Commands
This command removes the DMM from the idle state and into the wait for
trigger state. When the trigger occurs the subsequent readings are stored within
the DMM. These can then be accessed by the FETCh? command. Any readings
already in memory will be overwritten.
Syntax
Related Commands
INITiate[:IMMediate] (Event, No query)
ABORt, CONFigure, FETCh?, READ?, TRIGger
VX4237 Digital Multimeter Module User Manual
3–27
SCPI Commands
INITiate[:IMMediate]
This puts the DMM into the wait for trigger state. The DMM will then wait for
the appropriate trigger to occur before taking a measurement. If the trigger state
is set to TRIG:SOUR IMM then the DMM will take a reading immediately,
without waiting for any other event.
Any other trigger state set by the TRIG:SOUR command will cause the DMM to
wait until that event occurred before taking a reading.
The ABORt command can be used to remove the DMM from the wait for trigger
state.
Once the pending trigger conditions have been met, and all the readings have
been taken, then the DMM will return to the idle state and another INIT
command is required before further triggers are executed. The FETCh?
command can be used to access these readings.
The READ? command executes an INITiate command implicitly and the
MEASure? command executes a READ? command implicitly. Thus both
commands will put the DMM into the wait for trigger state. Note that if
TRIGger:SOURce IMMediate is in operation then these two commands will
implicitly cause a trigger. Once the trigger has occurred, then the measurement
will be placed in the output queue. Note that for external triggers, it will not be
possible to communicate with the DMM until the trigger has occurred. See
Appendix A to this section for further details.
Query Format
Errors
*RST Condition
Native Equivalents
INIT is an event and cannot be queried.
An error of –213, ‘Init ignored’ will be generated if the DMM is not in the idle
state when this command is received.
There is no associated *RST condition, but note that the *RST places the DMM
in the idle state.
No direct equivalent, but is related to X?, *TRG
3–28
VX4237 Digital Multimeter Module User Manual
INPut
SCPI Commands
Controls the connection of the input terminals to the signal to be measured. The
command is also used to configure the remote guard and the state of the input
filter.
Native Equivalents
Related Commands
Subsystem:
INPut
Alternatives/Parameters:
:COUPling AC|DC
:FILTer
[:LPASs]
[:STATe] <Boolean>
:GUARd LOW|FLOat
[:STATe] <Boolean>
:ZERO?
CONFigure, MEASure?, SENSe
VX4237 Digital Multimeter Module User Manual
3–29
SCPI Commands
INPut:COUPling AC|DC
This command is used to cause the DMM to measure the DC component of an
AC voltage signal. It is valid only when in AC voltage measurement, thus a
CONF or SENSe command must have already selected the AC function.
If the command is received with the AC parameter, then the DMM will only
measure the AC component. However sending the DC parameter will enable the
DMM to measure the DC and the AC components of the signal.
Errors
Query Format
*RST Condition
If the DMM is not in AC, then the error –221, ‘Settings conflict’ is generated.
INPut:COUPling?
This will return either the string “AC” or “DC”. If the DMM is in the Ohms
function, then this query will return “DC”.
– but inactive (See CONF:VOLT AC)
3–30
VX4237 Digital Multimeter Module User Manual
INPut:FILTer[:LPASs] [:STATe] <Boolean>
This sub-system configures the state of the input filter of the DMM. As the
DMM has effectively only a low pass filter, the other SCPI defined parameters
are not implemented.
Note that both :LPASs and :STATe are optional. If the value of <Boolean> is 0 or
OFF, then the filter is deselected. If <Boolean> is 1 or ON then the filter is
selected.
SCPI Commands
Errors
Query Format
*RST Condition
No associated errors.
INPut:FILTer[:LPASs] [:STATe]?
This will return the string ‘0’ if the filter is inactive or ‘1’ if the filter is active.
INPut:FILTer:LPASs:STATe 0 (Low-pass input Filter in OFF state)
VX4237 Digital Multimeter Module User Manual
3–31
SCPI Commands
INPut:GUARd LOW|FLOat
This command sets the connection of the internal guard shield:
Option Guard Connection
LOW internally connected to signal common
FLOat connected to front panel guard terminal
Errors
Query Format
*RST Condition
No associated errors
This queries the setting of the guard shield. Will return either “LOW” for
internally connected, or
“FL0” for connected to guard terminal.
3–32
VX4237 Digital Multimeter Module User Manual
INPut[:STATe] <Boolean>
SCPI Commands
Errors
Query Format
*RST Condition
This command controls whether the input terminals are connected to the
measurement signal. If<Boolean> is 0 or OFF then the DMM is isolated from
the external signal source. If <Boolean> is 1 or ON, then the DMM input is
connected to the external signal source.
No directly associated errors; however, it is not possible to take measurements if
the input is not connected to the signal. Thus a command such as MEAS ? and
INIT:IMM can generate errors as a result of the setting of INPut:[STATe]
Returns either ‘0’ if the input is disconnected or ‘1’ if the input is connected.
Note that this is different to that mandated by SCPI, but it is Datron’s policy to
disconnect all instruments from the signal lines. This isolation Will improve
safety and prevent internal damage due to inadvertently large inputs at power-on.
VX4237 Digital Multimeter Module User Manual
3–33
SCPI Commands
INPut:ZERO?
This command will cause the DMM to measure the current input value and
subtract this from all subsequent readings for the setting (i.e. function and range
etc.)
Errors
Query Format
*RST Condition
Native Equivalents
An execution error is generated if the measured value is outside the range of the
input zero correction range. The error 100, ‘Input not connected’ is reported if
this command is received and the input is disconnected.
INPut:ZERO?
This command returns 1 for a fail, 0 for a successful input zero.
All input zero corrections are unaffected by *RST.
INPut:COUPling AC|DC ACV ACCP DCCP
INPut:FILter FILT0/FILT1 in DCV etc.
INPut:[STATe] INPUT OFF, CH_A etc. ZERO?
INPut:ZERO ZERO?
3–34
VX4237 Digital Multimeter Module User Manual
MEASure?
SCPI Commands
This command configures the DMM, takes a measurement and then outputs the
reading to the output queue. This is equivalent to sending a CONE command
followed by a READ? command.
Syntax
Related Commands
MEASure <function>?<parameters> [,<source_list>]
Subsystem:
MEASure
Function:
:CURRent
[:DC]? <parameters> [,<source_list>]
:AC? <parameters> [,<source_list>]
:FRESistance? <parameters> [,<source_list>]
:RESistance? <parameters> [,<source_list>]
:VOLTage
[:DC]? <parameters> [,<source_list>]
:AC? <parameters> [,<source_list>]
Parameters:
[<expected_value>[,<resolution>]]
Source List:
[, [(@1)] | (@2) | (@1,2) | (@1:2)]
READ?, INPut, CONFigure
NOTE. INPut:STATe <Boolean> should be ON before measurement takes place.
See page 3–29 for further information on the INPut command.
As the MEASure? and CONFigure commands have the same structure — please
refer to this for a full description of CURRent, RESistance etc. For the format of
the data returned see the FETCh? command.
For the operation of MEAS? with the various trigger modes see Appendix A to
this section.
The MEASure command also allows for a <presentation layer>. This has not
been implemented on the VX4237.
Errors
VX4237 Digital Multimeter Module User Manual
If the input is not connected, then error 100, ‘Input not connected’ is reported.
If the DMM is in TRIGger:SOURCe BUS, then the error –214, Trigger deadlock
is reported.
3–35
SCPI Commands
OUTPut
This command is used to select the response mode of the DMM to a TTL trigger.
Syntax
Related Commands
OUTPut:TTLTrg<n>:PROTocol SYNChronous|ASYNchronous
Where n = 0 through 7, referring to the eight backplane lines.
TRIGger:SOURce:TTLTrg
3–36
VX4237 Digital Multimeter Module User Manual
OUTPut:TTLTrg<n>:PROTocol SYNChronous | ASYNchronous
This command is used to select the trigger protocol for the backplane TTL lines.
The SYNChronous mode configures the eight TTL lines as individual trigger
inputs. That is, a measurement can be triggered from any one of the lines if the
line is selected and INITiated.
In the ASYNchronous mode, the eight lines are treated as four input/output pairs
– 0/l, 2/3, 4/5, 6/7.
In this configuration the trigger is received on the lower number (i.e. TTLT0 / 2 /
4 / 6) and the measurement complete signal is output on the higher number (i.e.
TTLT1/3/5/7).
The ASYN command will select the pair of the currently active TTLT line. E.g.
if TTLT5 is selected ASYN would select pair 4/5.
Refer to VXI Specifications revision 1.4 for further information on triggering
protocols.
SCPI Commands
Query Format
Errors
*RST Condition
Native Equivalents
This query will return ‘SYNC’ or ‘ASYN’ depending on which is currently
selected.
No associated errors with this command.
mode, all TTLTrg lines deselected.
None
VX4237 Digital Multimeter Module User Manual
3–37
SCPI Commands
READ?
This command places the DMM in a ‘wait for trigger’ state and then returns the
measurement after the trigger. In effect this executes an INITiate and FETCh?
command
Syntax
Related Commands
Query Format
Errors
*RST Condition
Native Equivalents
READ ? (Query only)
CONFigure, FETCh? INITiate
See the FETCh? command for a description of the data format returned.
An execution error –100, ‘Input not connected’ will be generated if the DMM
input has not been selected with the INPut command.
If the DMM is in TRIGger:SOURce BUS, then the error –214, Trigger deadlock’
is reported. For the operation of READ? with the various trigger modes see
Appendix A.
Query command, no associated *RST state.
X?
3–38
VX4237 Digital Multimeter Module User Manual
[SENSe:]
SCPI Commands
This command is used to configure the DMM to a more detailed level that the
CONFigure command.
Note that :SENSe is a root level command and can be omitted. Thus only the
VOLTage, FILTer etc. part of the command need be sent. This command also
selects the line frequency that the measurements are taken over.
Syntax
[:SENSe]
Function
:CURRent
[:DC]
:RANGe <numeric_value>
:AUTO <Boolean>
:RESolution <numeric_value>
:AC
:RANGe <numeric_value>
:AUTO <Boolean>
:RESolution <numeric_value>
:FRESistance
:RANGe <numeric_value>
:AUTO <Boolean>
:RESolution <numeric_value>
:RESistance
:RANGe <numeric_value>
:AUTO <Boolean>
:RESolution <numeric_value>
:VOLTage
[:DC]
:RANGe <numeric_value>
:AUTO <Boolean>
:RESolution <numeric_value>
:AC
:RANGe <numeric_value>
:AUTO <Boolean>
:RESolution <numeric_value>
:FILTer
[:LPASs]
[:STATe] <Boolean>
:LFRequency <numeric_value>
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SCPI Commands
Related Commands
CONFigure, MEASure? INPut
As the six <function> defining sub-systems (see the list below) all have similar
sub-levels, they will all be described together:
[:SENSe]
:CURRent[:DC]
:CURRent:AC
:FRESistance
:RESistance
:VOLTage[:DC]
:VOLTage:AC
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[:SENSe]:<function>:RANGe <numeric_value>
[:SENSe]:<function>:RANGe:AUTO <Boolean>
These commands select the range of the specified function. The range selected
for any value of <expected_value> can be found in the tables in the CONFigure
command under the relevant <function>.
Note that these commands do NOT accept the special operators MAXimum,
MINimum, and DEFault.
The :AUTO parameter selects the autorange mode. In this setting, the DMM will
select the most appropriate range to measure the signal. Selecting a valid
RANGe will deselect autorange.
SCPI Commands
Query Format
[:SENSe]:<function>:RANGe? [MAXimum|MINimum]
[:SENSe]:<function>:RANGe:AUTO?
The query versions of these commands return the currently selected range. The
table below gives the returned string, depending on the <function>.
Current Resistance Voltage
1 1E2 1E–1
1E3 1E0
1E4 1E1
1E5 1E2
1E6 3E2
1E7
If the qualifier MINimum or MAXimum is present, then the following is
returned:
Parameter Current Resistance Voltage
MAXimum 1 1E2 1E–1
MINimum 1 1E7 3E2
the query for the AUTO parameter will return either ‘0’ if autorange is deselected
or ‘1’ if autorange is selected.
Errors
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See the CONFigure command for the errors associated with selecting combinations that are not available.
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SCPI Commands
*RST Condition
[:SENSe]:CURRent:DC:RANGe 1 inactive
[:SENSe]:RESistance:RANGe 1E7 inactive
[:SENSe]:FRESistance:RANGe 1E7 inactive
[:SENSe]:VOLTage:DC:RANGe 300 active
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[:SENSe]:<function>:RESolution <numeric_value>
As with the RESolution sub-command in the CONFigure command, this selects
the resolution of the measurements. Please refer to the settings as defined under
the CONFigure command (page 3–14).
SCPI Commands
Errors
Query Format
See the CONFigure command for the errors associated with selecting combinations that are not available.
[SENSe:]<function>:RESolution? [MINimum|MAXimum]
The query form will return one of the following strings as appropriate:
<function> <resolution>
CURRI CURR:AC 1E–6
1E–5
1E–4
RES I FRES <range> / 1E–6
<range> / 1E–5
<range> / 1E–4
VOL T I VOLT:AC <range> / 1E–6
<range> / 1E–5
<range> / 1E–4
If the qualifier MINimum or MAXimum is present then the following will be
returned for each of the above functions:
<parameter> <resolution>
MINimum <range> / 1E–4
MAXimum <range> / 1E–6
*RST Condition
[SENSe:]CURRent:DC:RESolution 1E-6 inactive
[SENSe:]RESistance:RESolution 1E1 inactive
[SENSe:]FRESistance:RESolution 1E1 inactive
[SENSe:]VOLTage:DC:RESolution 1E-3 active
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SCPI Commands
[SENSe:]FILTer[:LPASs] [:STATe] <Boolean>
This sub-system configures the state of the input filter of the DMM. As the
DMM effectively only has a low pass filter, the other SCPI defined parameters
are not implemented.
Note that both :LPASs and :STATe are optional. For a <Boolean> value of 0 or
OFF, the falter is deselected. For a <Boolean> value of 1 or ON the filter is
selected.
Errors
Query Format
*RST Condition
No associated errors
[SENSe:]<funCtiOn>:FILTer [:LPASs:] [STATe] ?
This will return the string ‘0’ or ‘1’ corresponding to filter inactive or filter
active.
[SENSe:]<function>:FILTer:LPASs:STATe:OFF
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[:SENSe]LFRequency<numeric_value>
This command is a Datron extension to the SCPI-confirmed [:SENSe] subsystem. It is used to set the line frequency at which the ADC converts. The table
below shows the accepted numeric values (nv) and the resulting line frequency
selection. Any other <numeric_value> will generate an error. The units are Hertz.
<numeric_value> (nv) Line Frequency Selected
0 < nv ≤55 50 Hz
55 < nv ≤100 60 Hz
100 < nv 400 Hz
MINimum 50 Hz
MAXimum 400 Hz
DEFault 60 Hz
SCPI Commands
Errors
Query Format
*RST Condition
Native Equivalents
If the parameter is less than zero an execution error will be generated.
[SENSe:]LFRequency?
The query form of the command returns the current setting of the line frequency.
and the current setting in the calibration stores. These will be either 50, 60 or
400, and the two values will be comma separated:
50, 60 <lf>
This would indicate that the temporary line frequency is 50 Hz, but the default
power on setting is 60 Hz. Note that the parameters MAX, MIN etc are not
applicable in this command.
The line frequency remains unchanged as it is stored in the non-volatile store.
DCV, DCI, ACV, ACI, OHMS, FILT, LINE
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SCPI Commands
STATus
This command controls the SCPI defined status reporting structures. The
commands that are listed in this section are the mandatory commands that must
be implemented by any SCPI instrument.
The status reporting is additional to that defined by the IEEE488.2 specification.
The extra status deals with the current operation of the instrument and quality of
any measurements taken.
For a diagram of the status register system please refer to the SCPI specification,
section 9.2, Figure 9.1.
Syntax
Related Commands
STATus
:OPERation
[:EVENt]? (Query Only)
:CONDition? (Query Only)
:ENABle <NRf>
:ENABle? (Query Only)
:QUEStionable
[:EVENt]? (Query Only)
:CONDition? (Query Only)
:ENABle <NRf>
:ENABle? (Query Only)
:PRESet (Event, No Query)
No directly-related SCPI commands.
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STATus:OPERation[:EVENt]?
This query command will return the latched settings from the operational status
register. The value that is returned is a binary weighted number. Thus converting
this number into a binary value will indicate which bits are set true.
The list below shows which bits of the operational register are used:
Bit Description
0 DMM is performing a calibration
2 DMM is currently range changing
4 DMM is currently measuring
5 DMM in wait for trigger state
Note that no other bits are used by the DMM and are returned as having the
value zero.
SCPI Commands
Errors
*RST Condition
Note that this command clears any bits that are currently set. Also sending the
*CLS command will clear any set bits.
There are no associated errors with this command.
As this is a query command, there is no associated *RST condition. However,
SCPI defines that the *RST will not affect the SCPI Event registers. The
operational register is cleared with a *CLR,OPER:EVENt? command or a
power-on.
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SCPI Commands
STATus:OPERation:CONDition?
This query command returns the current binary-weighted contents of the
operational status register. It is similar to the :EVENt ? query, except the
condition register is non-latched or buffered and as such returns what is currently
happening within the DMM.
Note that this command does not clear any of the set bits in the register. Also
note that because the DMM goes ‘busy’ during range change and calibration,
these bits will never be read true by this command.
Errors
*RST Condition
There are no associated errors with this command.
As this is a query command, there is no associated *RST condition. However,
SCPI defines that the *RST will not affect the SCPI Event registers. The only
way to clear the operational register is with a *CLR command or a power on.
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STATus:OPERation:ENABle <NRf>
This command is used to enable the summary and reporting of operational status
bits in the of <NRf> is converted into a weighted binary number and used as the
mask for the operational enable status register. If any of the enabled bits in the
operational status register are true, or subsequently go true, then bit 7 of the
Status Byte will be set true.
Note that the DMM only uses bits 0, 2 4 and 5 of the operational status register.
SCPI Commands
Errors
Query Format
*RST Condition
An error of –222, ‘Data out of range’ will be reported if the enable value is
greater that 6 5 5 3 5.
This returns an <NRf1> that is the binary weighted representation of enable bits
that are set.
SCPI defines that the *RST will not affect the SCPI Enable registers. The only
way to clear the operational register is with a *CLR command or at power on.
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SCPI Commands
STATus:QUEStionable[:EVENt]?
This command will return the latched settings from the questionable status
register, reporting information about the quality of the measurement. The value
that is returned is a binary-weighted decimal number. Converting this number
into a binary value will indicate which bits are set true.
The table below shows which bits of the questionable status register are used,
and the meaning of the response:
Bit Description
0 Voltage Overhang
1 Current Overrange
8 Invalid Calibration
9 Resistance Overrange
Errors
*RST Condition
Note that no other bits are used by the DMM and these are returned as having the
value zero. This command clears any bits that are currently set. Also sending the
*CLS command will clear any set bits.
There are no associated errors with this command.
As this is a query command, there is no associated *RST condition. However,
SCPI defines that the *RST will not effect the SCPI Event registers. The only
way to clear the questionable register is with a *CLR, STATus:QUEStionable[:EVENt]? command or at power on.
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STATus:QUEStionable:CONDition?
This query command returns the current binary weighted contents of the
questionable status register. It is similar to the :EVENt? query, except the
condition register is non-latched or buffered and as such returns what is currently
happening within the DMM.
Note that this command does not clear any of the set bits in the register.
SCPI Commands
Errors
*RST Condition
There are no associated errors
As this is a query command, there is no associated *RST condition. However,
SCPI defines that the *RST will not effect the SCPI Event registers. The only
way to clear the questionable register is with a *CLR command or at power on.
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SCPI Commands
STATus:QUEStionable:ENABle <NRf>
This command is used to enable the summary and reporting of questionable
status bits summarized by bit 3 of the IEEE 488.2 Status Byte. The value of
<NRf> is converted into a weighted binary number and used as the mask for the
operational enable status register. If any of the enabled bits in the operational
status register are true, or subsequently go true, then bit 3 of the Status Byte will
be set.
Note that the DMM only uses bits and 0, 1, 8 and 9 of the questionable status
register.
Errors
Query Format
*RST Condition
An error of –222, ‘Data out of range’ will be reported if the enable value is
greater that 65535.
This returns an <NRf1> that is the binary weighted representation of enable bits
that are set.
SCPI defines that the *RST will not effect the SCPI Enable registers. The only
way to clear the questionable register is with a *CLR command or at power on.
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STATus:PRESet
SCPI Commands
This command sets the SCPI defined Event and Enable registers into a known
state. See SCPI specification, Section II, 18.7 for details. The STATus:PRESet
condition is all bits set to zero (disabled) Positive Transition true.
Errors
*RST Condition
No associated errors with this command.
No associated *RST condition.
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SCPI Commands
SYSTem
The SYSTem command is used to query the current contents of the error queue.
It can also be used to switch the DMM into a different command language
interpreter, and it also reports the version of SCPI that the instrument conforms
to.
Syntax
Related Commands
Query Format
SYSTem
:ERRor? (Query only)
:LANGuage NATive
:VERSion? (Query only)
None.
SYSTem:ERROr?
This query command returns the error currently at the top of the error queue. The
format of the response is:
<NRf1>,‘<description>’
<NRf1> represents the error number and <description> is a short ASCII
description of the error.
If there are no errors currently in the queue then the DMM will return 0, ‘No
error’. If the queue overflows then the last error message added to the queue will
be replaced with the message –350, ‘Queue overflow’. The queue can store 10
errors before the overflow occurs.
The error queue is a First In, First Out system, thus the oldest error is reported
first.
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Errors
See the section entitled ‘Error Codes’ for a full list of the DMM errors. All error
numbers will be in the range: –32768 to +32767.
There are no errors associated with this command.
VX4237 Digital Multimeter Module User Manual
SYSTem:LANGuage NATive
This command causes the DMM to switch to the native command parser. This
will allow the control of the DMM with an IEEE488.2 compatible language.
Refer to the VX4237 VXIbus Card DMM Users Handbook for language use.
Once in native mode, control can be returned to the SCPI parser by the native
command ‘SCPI.’
SCPI Commands
Errors
Query Format
*RST Condition
There are no errors associated with this command.
There are no associated errors.
An *RST will not change the current parser mode. Thus once this command has
been issued, the only way back is by using the native command ‘SCPI.’
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SCPI Commands
SYSTem:VERSion?
This query command will report the version of SCPI that the instrument
conforms to. The returned <NRf2> is:
Errors
*RST Condition
There are no associated errors.
No associated *RST.
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TEST
SCPI Commands
This command performs an instrument self test. It may be either one specific test
or a complete run of all tests.
Syntax
Related Commands
TEST
[:ALL] ? (Query only)
TYPE ? <numeric_value> (Query only)
*TST
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SCPI Commands
TEST[:ALL]?
This query command performs the complete self test and then returns a number
to indicate the result of the test. This will be either ‘0’ if all tests pass or the
specific test number of the test that failed. These will be the numbers already
defined for the VX4237 native self test. During the self test, once a test falls the
DMM does not proceed with the testing.
Errors
*RST Condition
Only the test failed number.
There is no associated *RST condition. Self test is not active.
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TEST:TYPE? <numeric_value>
This query command performs the specified number test. It then returns the same
data as the native VX4237 TEST? command.
SCPI Commands
Errors
Native Equivalents
None
TEST?, *TST?. Note that this will use the current VX4237 self test structure.
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SCPI Commands
TRIGger
This command controls the behavior of the trigger system. It specifies where the
trigger is to originate, any delays between the trigger and the measurement and
how many measurements to take.
The basic principle of the SCPI trigger system is that an instrument is normally
in an IDLE state, see Figure 3–1. This is the state after an *RST, ABORt or
power on. The instrument may then be initiated from the idle state by placing it
into the ARM state. This is an Event Detection Layer at which the instrument
will wait until the specified event has occurred.
Once the ARM event(s) have occurred then the instrument will move into the
TRIGGER state. This is again an Event Detection Layer and the instrument will
wait for the specified event to occur before commencing with the measurement.
Once this specified number of ARM and TRIGGER states have been satisfied,
then the DMM will return to the IDLE state.
The VX4237 DMM does not implement the ARM layer of the trigger subsystem.
Thus the DMM will proceed from the IDLE state directly to the trigger state.
There are two routes out of this state – either an ABORt (or equivalent)
command to return the DMM to IDLE, or the specified trigger Event. In this
later case, the DMM will take a measurement before returning to the IDLE state.
Syntax
If the TRIGger:COUNt command has been set to more that the default of 1, then
the DMM will wait for COUNt triggers, taking a measurement for each one,
before returning to the IDLE state.
TRIGger
[:IMMediate] (Event, No Query)
:COUNt <numeric_value>
:DELay <numeric_value>
:AUTO <Boolean>
SOURce BUS | EXTernal | HOLD | IMMediate | TTLTrg<n>
Where n = 1 to 7
NOTE. See Operating Basics for further information on the trigger subsystem
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SCPI Commands
Related Commands
ABORt, MEASure?, CONFigure, READ?, INITiate, FETCh?
ABORt *RST
or Power On
Trigger System
Initiated
(Still) Initiated
Trigger Conditions
Satisfied
IDLE
No Longer
Initiated
Initiated
Complete # of
TRIGger Loops
Wait for
Trigger
Trigger Action
Complete
Measure
Figure 3–1: Trigger State Diagram
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SCPI Commands
TRIGger[:IMMediate]
If the DMM is in the Wait-for-trigger state set by the INITiate command, then
the DMM will take a measurement. The measurements can then be recalled
using the FETCh? command. Note that the DMM must be in either TRIG:SOUR
BUS or TRIG:SOUR HOLD state for this command to trigger the DMM and not
generate an error.
Errors
Query Format
*RST Condition
An error of 211, ‘Trigger ignored’ will be generated if the DMM has not been
initiated with an INIT command. (Thus from this command the error will be
generated if TRIG:SOURce IMM is selected).
This is an event and thus cannot be queried.
On *RST the DMM is placed into the Idle state.
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