Racal Instruments 2461 User manual

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200MHz UNIVERSAL
COUNTER TIMER
User Manual
MODEL 2461 Type C
Publication No. 980833-002
RACAL INSTRUMENTS
United States
(Corporate Headquarters and Service Center)
4 Goodyear Street, Irvine, CA 92618
Tel: [phone]; Fax: [phone]
5730 Northwest Parkway Suite 700, San Antonio, TX 78249
Tel: [phone]; Fax: [phone]
Europe
(European Headquarters and Service Center)
18 Avenue Dutartre, 78150 LeChesnay, France
Tel: [phone]; Fax: [phone]
29-31 Cobham Road, Wimborne, Dorset BH21 7PF, United Kingdom
Tel: [phone]; Fax: [phone]
Via Milazzo 25, 20092 Cinisello B, Milan, Italy
Tel: [phone]; Fax: [phone]
Technologie Park, Friedrich Ebert Strasse, 51429 Bergisch Gladbach, Germany
Tel: [phone]; Fax: [phone]
[email protected]
[email protected]
[email protected]
http://www.racalinstruments.com/
PUBLICATION DATE: November 19, 2004
Copyright 1998 by Racal Instruments, INC. Printed in the United States. All rights reserved.
This book or parts thereof may not be reproduced in any form without written permission of the publisher.
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THANK YOU FOR PURCHASING THIS RACAL INSTRUMENTS PRODUCT.
For this product, or any other Racal Instruments product that incorporates software drivers, you
may access our web site to verify and/or download the latest driver versions. The web address for
driver downloads is:
http://www.racalinstruments.com/downloads
If you have any questions about software driver downloads or our privacy policy, please contact us
at
[email protected].
WARRANTY STATEMENT
All Racal Instruments, Inc. products are designed and manufactured to exacting standards and in
full conformance to Racal’s ISO 9000/2000 procedures.
This warranty does not apply to defects resulting from any modification(s) of any product or part
without Racal Instruments express written consent, or misuse of any product or part. The warranty
also does not apply to fuses, software, non-rechargeable batteries, damage from battery leakage,
or problems arising from normal wear, such as mechanical relay life, or failure to follow instructions.
This warranty is in lieu of all other warranties, expressed or implied, including any implied warranty
of merchantability or fitness for a particular use. The remedies provided herein are buyer’s sole and
exclusive remedies.
For the specific terms of your standard warranty, or optional extended warranty or service
agreement, contact your Racal customer service advisor. Please have the following information
available to facilitate service.
1. Product serial number
2. Product model number
3. Your company and contact information
You may contact your customer service advisor by:
E-Mail: [email protected]
Telephone: [phone] (USA)
[phone] (UK)
Fax: [phone] (USA)
[phone] (UK)
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RETURN of PRODUCT
Authorization is required from Racal Instruments before you send us your product for service or
calibration. Call your nearest Racal Instruments support facility. A list is located on the last page of
this manual. If you are unsure where to call, contact Racal Instruments, Inc. Customer Support
Department in Irvine, California, USA at 1-800-722-3262 or 1-949-859-8999 or via fax at 1-949-859-
7139. We can be reached at: [email protected].
PROPRIETARY NOTICE
This document and the technical data herein disclosed, are proprietary to Racal Instruments, and
shall not, without express written permission of Racal Instruments, be used, in whole or in part to
solicit quotations from a competitive source or used for manufacture by anyone other than Racal
Instruments. The information herein has been developed at private expense, and may only be used
for operation and maintenance reference purposes or for purposes of engineering evaluation and
incorporation into technical specifications and other documents which specify procurement of
products from Racal Instruments.
DISCLAIMER
Buyer acknowledges and agrees that it is responsible for the operation of the goods purchased
and should ensure that they are used properly and in accordance with this handbook and any
other instructions provided by Seller. Racal Instruments products are not specifically designed,
manufactured or intended to be used as parts, assemblies or components in planning,
construction, maintenance or operation of a nuclear facility, or in life support or safety critical
applications in which the failure of the Racal Instruments product could create a situation where
personal injury or death could occur. Should Buyer purchase Racal Instruments product for such
unintended application, Buyer shall indemnify and hold Racal Instruments, its officers, employees,
subsidiaries, affiliates and distributors harmless against all claims arising out of a claim for
personal injury or death associated with such unintended use.
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FOR YOUR SAFETY
Before undertaking any troubleshooting, maintenance or exploratory procedure, read carefully the
WARNINGS and CAUTION notices.
This equipment contains voltage hazardous to
human life and safety, and is capable of
inflicting personal injury.
If this instrument is to be powered from the AC line (mains) through an
autotransformer, ensure the common connector is connected to the neutral (earth
pole) of the power supply.
Before operating the unit, ensure the conductor (green wire) is connected to the
ground (earth) conductor of the power outlet. Do not use a two-conductor extension
cord or a three-prong/two-prong adapter. This will defeat the protective feature of the
third conductor in the power cord.
Maintenance and calibration procedures sometimes call for operation of the unit with
power applied and protective covers removed. Read the procedures and heed
warnings to avoid “live” circuit points.
Before operating this instrument:
1. Ensure the proper fuse is in place for the power source to operate.
2. Ensure all other devices connected to or in proximity to this instrument are properly grounded or
connected to the protective third-wire earth ground.
If the instrument:
- fails to operate satisfactorily
- shows visible damage
- has been stored under unfavorable conditions
- has sustained stress
Do not operate until, performance is checked by qualified personnel.
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2461Type C User Manual
i
Table of Contents
Chapter 1 ............................................................................................................................1-1
GENERAL......................................................................................................................................1-1
Introduction ....................................................................................................................................1-1
Brief Description.............................................................................................................................1-2
Outstanding Resolution.................................................................................................................. 1-2
High Speed Time Measurement ....................................................................................................1-2
Measurement Time Out .................................................................................................................1-2
High Performance Trigger..............................................................................................................1-3
Voltage Measurements .................................................................................................................. 1-3
Individual Channel Filtering............................................................................................................1-3
Selectable Sensitivity .....................................................................................................................1-4
Pulse Characterization...................................................................................................................1-4
Phase Measurement......................................................................................................................1-4
Powerful Arming Capability............................................................................................................1-5
High Stability Time Base................................................................................................................1-5
Special Configurations ...................................................................................................................1-5
Measurement Block ....................................................................................................................... 1-5
Measurement Principles ................................................................................................................1-6
Chapter 2.............................................................................................................................2-1
INSTALLATION INSTRUCTIONS..................................................................................................2-1
Unpacking and Inspection..............................................................................................................2-1
Reshipment Instructions ................................................................................................................2-1
Installation......................................................................................................................................2-2
Label Requirements.......................................................................................................................2-5
Chapter 3.............................................................................................................................3-1
THEORY OF OPERATION ............................................................................................................3-1
Functional Systems........................................................................................................................ 3-1
Input Channels 1 & 2 System ........................................................................................................3-1
Input Channel 3 System.................................................................................................................3-2
Measurement System ....................................................................................................................3-5
Microprocessor System .................................................................................................................3-8
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2461Type C User Manual
ii
Details of the Counter .................................................................................................................... 3-9
Measurement Functions .............................................................................................................. 3-10
Signal Inputs ................................................................................................................................ 3-14
Additional Capabilities .................................................................................................................3-14
Chapter 4............................................................................................................................. 4-1
PROGRAMMING THE TYPE C FUNCTION CARD ...................................................................... 4-1
Introduction .................................................................................................................................... 4-1
Default Conditions ......................................................................................................................... 4-1
Functional Check ........................................................................................................................... 4-4
INTRODUCTION ........................................................................................................................... 4-4
VXIBUS Communication Check..................................................................................................... 4-4
List of SCPI Commands................................................................................................................. 4-5
2461 TYPE C Commands..............................................................................................................4-10
CALCULATE Subsystem ...............................................................................................................4-10
MeASUREMENT Subsystem.........................................................................................................4-12
CONFigure Subsystem .......................................................................................................4-12
FETCh Subsystem ............................................................................................................ 4-24
MEASure Subsystem ........................................................................................................ 4-27
READ Subsystem ........................................................................................................................ 4-38
INPut Subsystem ......................................................................................................................... 4-39
OUTPut Subsystem ..................................................................................................................... 4-50
SENSE SUBSYSTEM.................................................................................................................. 4-51
SOURCE SUBSYSTEM .............................................................................................................. 4-61
TEST SUBSYSTEM..................................................................................................................... 4-62
TRIGGER SUBSYSTEM ............................................................................................................. 4-68
2461 TYPE C-Specific Error Messages....................................................................................... 4-75
Examples Of SCPI Commands Used To Manipulate The Instrument............................................4-75
Selecting The Counter Function Card............................................................................................4-76
Preparation For Measurement.......................................................................................................4-76
Triggering And Retrieving Measurements......................................................................................4-77
BASICS............................................................................................................................. 4-78
MULTIPLE MEASUREMENTS ......................................................................................... 4-78
AUTOMATIC RESOLUTION.............................................................................................4-79
Chapter 5.............................................................................................................................5-1
USING THE VXI plug&play INSTALL DISKS ................................................................................ 5-1
Operating The VXI plug&play Install Disk ...................................................................................... 5-1
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2461Type C User Manual
iii
Using The Soft Front Panel............................................................................................................5-1
Arm Source Configuration..............................................................................................................5-5
Configure Inputs.............................................................................................................................5-6
Select Reference ...........................................................................................................................5-8
Configure Math Function................................................................................................................5-9
About............................................................................................................................................5-10
Chapter 6.............................................................................................................................6-1
PERFORMANCE VERIFICATION AND ADJUSTMENTS ............................................................. 6-1
Introduction ....................................................................................................................................6-1
Test Equipment Required ..............................................................................................................6-1
Input 1 Sensitivity Test...................................................................................................................6-2
Input 2 Sensitivity Test...................................................................................................................6-4
Input 3 Performance Verification....................................................................................................6-6
Time Interval 1:2 Test ....................................................................................................................6-8
Totalize 1 by 2 Test......................................................................................................................6-10
Ratio 1:2 Test...............................................................................................................................6-11
Trigger Level Accuracy Test ........................................................................................................6-12
Functional Checks .......................................................................................................................6-14
Input 1 Filter Check......................................................................................................................6-14
Input 2 Filter Check......................................................................................................................6-15
Input 1 Attenuator Check .............................................................................................................6-17
Input 2 Attenuator Check .............................................................................................................6-18
Hysteresis Check for Input 1........................................................................................................6-19
Hysteresis Check for Input 2........................................................................................................6-19
Calibration, External Standard Output (2461-Ce and 2461-Cf) ...................................................6-20
Chapter 7............................................................................................................................. 7-1
PRODUCT SUPPORT...................................................................................................................7-1
Product Support .............................................................................................................................7-1
Reshipment Instructions ................................................................................................................7-1
Appendix A: SPECIFICATIONS.................................................................................................... A-1
Appendix B: APPLICATION NOTES............................................................................................. B-1
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2461Type C User Manual
iv
List of Figures
Figure 1-1, Universal Counter Timer 2461 Type C Function Card ................................................1-1
Figure 1-2, High Speed Time Measurement..................................................................................1-2
Figure 1-3, High Performance Trigger ...........................................................................................1-3
Figure 1-4, Selectable Sensitivity ..................................................................................................1-4
Figure 1-5, Pulse Characterization ................................................................................................1-4
Figure 1-6, Powerful Arming Capability .........................................................................................1-5
Figure 1-7, Measurement Block.....................................................................................................1-7
Figure 2-1, The Universal Counter Timer ......................................................................................2-2
Figure 2-2, Removing the Screws from the Module.......................................................................2-3
Figure 2-3, Removing the Front Panel...........................................................................................2-3
Figure 2-4, The 2461 Type C.........................................................................................................2-4
Figure 2-5, Tightening the Four Screws. .......................................................................................2-4
Figure 2-6, The Racal Instruments Label ......................................................................................2-5
Figure 3-1, Inputs 1 &2 ..................................................................................................................3-4
Figure 3-2, Measurement Block.....................................................................................................3-7
Figure 3-3, Block diagram of processor system.............................................................................3-9
Figure 5-1, 2461-C Front Panel .....................................................................................................5-2
Figure 5-2, Configure Arming secondary panel .............................................................................5-5
Figure 5-3, Configure Input secondary panel ................................................................................5-6
Figure 5-4, Select Reference.........................................................................................................5-8
Figure 5-5, Configure Math Function secondary panel..................................................................5-9
Figure 5-6, About secondary panel..............................................................................................5-10
Figure 6-1, Input 1 Low Frequency Sensitivity Test Configuration ................................................6-2
Figure 6-2, Input 2 Low Frequency Sensitivity Test Configuration ................................................6-4
Figure 6-3, Time Interval 1-2 Test Configuration ...........................................................................6-8
Figure 6-4, Totalize 1 by 2 Test Configuration.............................................................................6-10
Figure 6-5, Ratio 1 : 2 Test Configuration....................................................................................6-11
Figure 6-6 Input 1 Trigger Level Test Configuration ....................................................................6-12
Figure 6-7, Input 1 Filter Check Configuration.............................................................................6-14
Figure 6-8, Input 2 Filter Check Configuration.............................................................................6-15
Figure 6-9, Input 1 X10 Attenuator Check Configuration.............................................................6-17
Figure 6-10, Input 2 X10 Attenuator Check Configuration...........................................................6-18
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2461Type C User Manual
v
Figure 6-11, External Standard Output ........................................................................................6-20
List of Tables
Table 6-1, Input 1 Sensitivity Low Frequency Test ........................................................................6-2
Table 6-2, Input 1 Sensitivity high Frequency Performance Limits................................................6-3
Table 6-3, Input 2 Sensitivity Low Frequency Tests ......................................................................6-5
Table 6-4, Input 2 Sensitivity High Frequency Tests .....................................................................6-5
Table 6-5, Time Interval 1-2 Test Performance Limits...................................................................6-9
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2461Type C User Manual
vi
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2461Type C User Manual
Racal Instruments 1998 General 1-1
Chapter 1
GENERAL
Introduction The type C card is a high performance universal counter designed
to be used with the innovative RACAL Instruments 2460 Series,
VXI Modules.
The Counter card offers eleven automatic measurement functions,
including phase, pulse, peak, rise/fall time, time interval and ratio
measurement, all with extremely high resolution.
To perform high performance measurement, the Counter card
includes one filter per channel and a selectable hysteresis.
The Cd card does not include an oscillator. The Ce has a TCXO
oscillator and the Cf card a high performance OCXO oscillator.
Figure 1-1, Universal Counter Timer
2461 Type C Function Card
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2461Type C User Manual
General 1-2 Racal Instruments 1998
Brief Description The 2461 Type C card is a member of the 2460 series instruments.
The 2461 Type C card is a high performance Universal Counter
(UCT) offering eleven automatic measurement functions :
• Frequency
• Period
• Time Interval
• Time Interval Delay
• Rise Time
• Fall Time
• Pulse Width
• Frequency Ratio channel 1 to 2 (Ratio 3 to 2 optional)
• Totalize
• Phase
• Voltage (Voltage High, Voltage Low and Average Voltage)
Outstanding
Resolution
The 2461 Type C card offers 200 MHz frequency range
measurements with a resolution going up to 10 digits per second.
In time interval the resolution is 1 ns in single shot and 100 ps in
average mode.
High Speed Time
Measurement
By using Timing Error Correction (TEC) in combination with
traditional recipromatic techniques, measurement time may be
minimized without any compromise in performance.
Figure 1-2, High Speed Time Measurement
Measurement Programmable measurement Time-out helps the user to optimize
system performance when of the input signal is missing
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2461Type C User Manual
Racal Instruments 1998 General 1-3
Time Out system performance when of the input signal is missing.
High
Performance
Trigger
In Manual mode, the trigger level is programmable from – 5.1 V to
+ 5.1 V with the exceptional resolution of 2.5 mV.
An automatic trigger mode is also available covering a frequency
range of DC and 50 Hz to 200 MHz.
Figure 1-3, High Performance Trigger
Voltage
Measurements
Automatic triggering is used to establish the peak DC voltages for
setting trigger points. This feature is used to measure Voltage
High, Voltage Low and Average Voltage.
Individual
Channel Filtering
The 2461 Type C card offers independent 50 kHz low pass filters
on each channel to allow measurements in noisy configurations.
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2461Type C User Manual
General 1-4 Racal Instruments 1998
Selectable
Sensitivity
The sensitivity of the counter can be decreased to perform
measurement on a low level signal with noise. This characteristic
is very important for system applications, requiring measurement
of signals in noisy configurations.
Figure 1-4, Selectable Sensitivity
Pulse
Characterization
The 2461 Type C board provides automatic pulse characterization
including Rise time, Fall time and pulse Width measurements.
Figure 1-5, Pulse Characterization
Phase
Measurement
Phase measurements are performed automatically.
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2461Type C User Manual
Racal Instruments 1998 General 1-5
Powerful Arming
Capability
The 2461 Type C card offers powerful arming capability. Different
modes are provided with the ability to select the arming source
among the external arming input and the VXI TTLtrig lines.
Figure 1-6, Powerful Arming Capability
High Stability
Time Base
Counter measurement stability can be improved by using an
external clock or an optional internal high stability time base. Two
types of internal time base are optional:
• TCXO (Ce card)
• OCXO (Cf card)
Special
Configurations
The Cd, Ce and Cf cards are fitted with additional internal
connectors for future applications.
Measurement
Block
The measurement block is mainly implemented with an Altera
Erasable Programmable logic Device (EPLD). The Timing Error
Correction (TEC) circuit is external to this.
Referring to the block diagram Figure 1-7, the measurement block
consists of a high speed front end which takes in Inputs 1 & 2 after
conditioning by the input amplifiers. This front end connects to the
microprocessor data bus to allow the micro to configure the
measurement block for the type of measurement to be taken. The
micro also drives the measurement process by controlling the
arming of the start and stop of the measurement.
After a measurement has taken place, the micro reads the values
in the various counting chains via the data bus. The measurement
block uses interrupts to communicate the various events that occur
in the measurement block.
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2461Type C User Manual
General 1-6 Racal Instruments 1998
Measurement
Principles
The measurement technique employed is known as the
recipromatic measurement technique. In this technique the signal
and reference are counted simultaneously. This has the advantage
that for signals of less than 10 MHz, accuracy is maintained
because of the large number of counts in the reference counter. In
addition the opening and closing of the gate is synchronized to the
signal which, together with the Timing Error Correction (TEC)
circuit allows higher resolution equivalent to a 1GHz reference.
In this system, the first edge of the incoming frequency to be
measured (after the µP has armed the start of measurement),
opens the gate and simultaneously allows the signal through to the
input 1 counting chain and the frequency reference through to the
reference counting chain. Both signals are now counted for the
duration of the gate time. The µP determines the length of the gate
time using its on-board timer, which is set by the operator.
At the end of the gate time, the µP arms the end of measurement
and the next edge of the input signal closes the gate and the two
counting chains stop counting.
In the above description, there are two points at which resolution is
limited by the 10 MHz reference, the opening of the gate and the
closing. To overcome this limitation, the time between the signal
opening the gate and the next edge of the reference is detected by
logic gates in the front end and a pulse whose width is proportional
to this time is generated. This pulse is then used to charge a
capacitor with a constant current source so the charge on the
capacitor is proportional the time error. The charge is then
discharged at much slower rate and while this is going on the
reference is counted in the start counting chain. When the
capacitor is discharged then the count in the start counting chain
represents the error between the opening of the gate and the next
counting edge of the reference (see Figure 1-7).
This process is repeated at the closure of the gate by a separate
TEC and counting circuit (the stop counting chain).
After the measurement results have been read out of all counters,
calibrated pulses, derived from the reference, are fed to the TEC
circuits. This is done for two pulse widths for both start and stop
circuits. The resultant counts are then used to calibrate the TEC
circuits. Once these are calibrated the value of the frequency of
the input can be calculated to a much greater resolution.
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2461Type C User Manual
Racal Instruments 1998 General 1-7
Figure 1-7, Measurement Block
Gate Control, Function & Multiplex circuits
Input 1 Counting chain Reference/ Input 2 Counting Chain
BUFFER
To Microcontroller Data Bus
Timing Error
Correction
Circuit(TEC)
Start Correction
Stop Correction
Start Counting chain Stop Counting Chain
Reference(CLOCK10/INTERNAL/EXTERNAL)
External Ref(Front Panel)
BUFFER
From Microcontroller Address Bus
Input 1
Input 2
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