Tektronix VXOA41 User manual

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User Manual
VXOA41
Optical Attenuator
070-8777-01

Copyright Tektronix, Inc. All rights reserved.
Tektronix 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.
Tektronix, Inc., P.O. Box 1000, Wilsonville, OR 97070–1000
TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.

WARRANTY
Tektronix warrants that the products that it manufactures and sells will be free from defects in materials and workmanship for a
period of three (3) years from the date of shipment. If a product proves defective during this warranty period, Tektronix, 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 Tektronix, with shipping charges prepaid. Tektronix shall pay for the return
of the product to Customer if the shipment is to a location within the country in which the Tektronix 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. Tektronix shall not be obligated to furnish service under this warranty a) to repair damage resulting from attempts by
personnel other than Tektronix representatives to install, repair or service the product; b) to repair damage resulting from improper
use or connection to incompatible equipment; c) to repair any damage or malfunction caused by the use of non-Tektronix supplies;
or d) 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 IN LIEU OF ANY OTHER WARRANTIES, EXPRESS 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 CUSTOMER 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.

VXOA41 Optical Attenuator User Manual i
Table of Contents
List of Figures iii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
List of Tables iv. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety Summary v. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Getting Started
Getting Started 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
First Time Operation 1–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 1–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checkout Procedure 1–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Basics
Operating Basics 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front-Panel Indicators and Connectors 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reference
Command Syntax 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clearing the VXOA41 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Command and Query Structure 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Command Entry 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Argument Types 3–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Syntax Diagrams 3–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Commands 3–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Common Commands and Queries 3–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Device Commands and Queries 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ADJusting? (Query Only) 3–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ALLev? (Query Only) 3–12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ATTenuation 3–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ATTenuation:INCRement 3–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ATTenuation:NEXT 3–14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ATTenuation:TRIGger 3–15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ATTenuation:TPOLarity 3–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BLRN 3–16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*CAL? (Query Only) 3–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*CLS (No Query Form) 3–17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DESE 3–18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DISable 3–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*ESE 3–19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*ESR? (Query Only) 3–20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EVENt? (Query Only) 3–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EVMSg? (Query Only) 3–21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EVQTy? (Query Only) 3–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FACTory (No Query Form) 3–22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
HEADer 3–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*IDN? (Query Only) 3–24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*LRN? or SET? 3–25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Table of Contents
ii VXOA41 Optical Attenuator User Manual
*OPC 3–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*OPT? (Query Only) 3–26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*PSC 3–27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RECall (No Query Form) 3–27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REFerence 3–28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*RST (No Query Form) 3–28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*SRE 3–29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*STB? (Query Only) 3–30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
STORe 3–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*TST? (Query Only) 3–31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VERBOSE 3–32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*WAI (No Query Form) 3–33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WAVelength 3–33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Status and Events 3–35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Registers 3–35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Queues 3–39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Event Handling Sequence 3–39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conflicts 3–40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Messages 3–41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendices
Appendix A: Accessories and Options A–1. . . . . . . . . . . . . . . . . . . . . . . . . .
Standard Accessories A–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Accessories A–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Options A–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix B: Specifications B–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix C: Interface Specifications C–1. . . . . . . . . . . . . . . . . . . . . . . . . .
Interface Standard C–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Character Set (ASCII Chart) C–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VXI Word Serial Commands C–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix D: Using the *OPC Query/Command D–1. . . . . . . . . . . . . . . . .
Appendix E: Packing for Shipment E–1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix F: Maintenance F–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning the Optical Ports F–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing the Optical Port Connectors F–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix G: Performance Verification G–1. . . . . . . . . . . . . . . . . . . . . . . . .
Equipment List G–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Up G–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Panel LEDs G–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shutter Attenuation and Disable G–5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Insertion Loss (Long Wavelengths) G–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Insertion Loss (Short Wavelengths) G–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repeatability and Accuracy G–11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix H: Replaceable Parts H–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Ordering Information H–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using the Replaceable Parts List H–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Glossary and Index

Table of Contents
VXOA41 Optical Attenuator User Manual iii
List of Figures
Figure 1-1: Logical Address Switch location on the VXOA41 1–4. . . . . .
Figure 1-2: Removing the VXOA41 from the Mainframe 1–5. . . . . . . . .
Figure 2-1: VXOA41 Front Panel (Option 1 Shown) 2–2. . . . . . . . . . . . . .
Figure 3-1: Command Message Elements 3–2. . . . . . . . . . . . . . . . . . . . . . .
Figure 3-2: Block Argument Example 3–6. . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3-3: Typical Syntax Diagrams 3–7. . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3-4: The Standard Event Status Register (SESR) 3–36. . . . . . . . . .
Figure 3-5: The Status Byte Register (SBR) 3–36. . . . . . . . . . . . . . . . . . . . .
Figure 3-6: The Device Event Status Enable Register (DESER) 3–37. . . .
Figure 3-7: The Event Status Enable Register (ESER) 3–38. . . . . . . . . . . .
Figure 3-8: The Service Request Enable Register (SRER) 3–38. . . . . . . . .
Figure 3-9: Status and Event Handling Process 3–40. . . . . . . . . . . . . . . . . .
Figure F-1: Removing the Optical Bulkhead Connector F–2. . . . . . . . . . .
Figure F-2: FC Optical Bulkhead Assembly F–3. . . . . . . . . . . . . . . . . . . . .
Figure F-3: ST Optical Bulkhead Assembly F–4. . . . . . . . . . . . . . . . . . . . .
Figure F-4: DIN 47256 Optical Bulkhead Assembly F–4. . . . . . . . . . . . . .
Figure F-5: SC Optical Bulkhead Assembly F–5. . . . . . . . . . . . . . . . . . . . .
Figure G-1: Setup for Shutter Attenuation and Disable Procedure G–5. .
Figure G-2: First setup for Insertion Loss Procedure G–7. . . . . . . . . . . . .
Figure G-3: Second setup for Insertion Loss Procedure G–8. . . . . . . . . . .
Figure G-4: First setup for Insertion Loss Procedure G–9. . . . . . . . . . . . .
Figure G-5: Second setup for Insertion Loss Procedure G–10. . . . . . . . . . .
Figure G-6: Setup for Repeatability and Accuracy Procedure G–11. . . . . .
Figure H-1: VXOA41 Replaceable Parts H–4. . . . . . . . . . . . . . . . . . . . . . .

Table of Contents
iv VXOA41 Optical Attenuator User Manual
List of Tables
Table 1–1: VXOA41 Module Power Requirements 1–2. . . . . . . . . . . . . . .
Table 3–1: BNF Symbols and Meanings 3–1. . . . . . . . . . . . . . . . . . . . . . . .
Table 3–2: Command Message Elements 3–2. . . . . . . . . . . . . . . . . . . . . . .
Table 3–3: Comparison of Header On and Off Responses 3–3. . . . . . . . .
Table 3–4: Block Argument Elements 3–5. . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–5: Numeric Argument Descriptions 3–6. . . . . . . . . . . . . . . . . . . .
Table 3–6: Commands Common to All GPIB Devices and Supported
by the VXOA41 3–10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–7: VXOA41 Device Commands and Parameters 3–11. . . . . . . . .
Table 3–8: FACTory Default Settings 3–23. . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–9: Results from *TST? 3–32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–10: SESR Bit Functions 3–36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–11: SBR Bit Functions 3–37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–12: No Event Messages 3–41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–13: Command Error Messages — CME Bit 5 3–41. . . . . . . . . . . .
Table 3–14: Execution Error Messages — EXE Bit 4 3–42. . . . . . . . . . . . .
Table 3–15: Device Error Messages — DDE Bit 3 3–43. . . . . . . . . . . . . . .
Table 3–16: System Event Messages — QYE Bit 2 3–43. . . . . . . . . . . . . . .
Table 3–17: Execution Warning Messages — EXE Bit 4 3–44. . . . . . . . . .
Table B–1: Optical Characteristics B–1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table B–2: Physical Characteristics B–2. . . . . . . . . . . . . . . . . . . . . . . . . . .
Table B–3: Environmental Performance B–2. . . . . . . . . . . . . . . . . . . . . . .
Table B–4: Certifications and Compliances B–3. . . . . . . . . . . . . . . . . . . . .
Table C–1: The ASCII Character Set C–2. . . . . . . . . . . . . . . . . . . . . . . . . .

VXOA41 Optical Attenuator User Manual v
Safety Summary
You might be eager to begin using your VXOA41, but please take a moment to
review these safety precautions. They are provided for your protection and to
prevent damage to the VXOA41 Optical Attenuator. This safety information
applies to all operators and service personnel.
Symbols and Terms
These two terms appear in manuals:
CAUTION. Caution statements identify conditions or practices that could result in
damage to the equipment or other property.
WARNING. Warning statements identify conditions or practices that could result
in personal injury or loss of life.
These two terms appear on equipment:
CAUTION indicates a personal injury hazard not immediately accessible as
one reads the marking, or a hazard to property including the equipment itself.
DANGER indicates a personal injury hazard immediately accessible as one
reads the marking.
This symbol appears in manuals:
Static-Sensitive Devices
These symbols appear on equipment:
DANGER
High Voltage Protectiveground (earth)terminal ATTENTION Refer to manual

Safety Summary
vi VXOA41 Optical Attenuator User Manual
Specific Precautions
Observe all of these precautions to ensure your personal safety and to prevent
damage to either the VXOA41 or equipment connected to it.
WARNING. To prevent damage to your eyes, avoid looking into the optical output port
while there is an optical signal connected to the input port. Even if the VXOA41 is
switched off, light can pass through the attenuator. Always attach the output port to a
receiver before attaching the source signal to the input port.
The VXOA41 is designed for operation in a C-size or D-size VXI mainframe. To
ensure safe operation, follow all precautions listed in the instrument’s documen-
tation. Do not attempt to operate the VXOA41 with any other power source.
The VXOA41 is grounded through the VXI mainframe. To avoid electric shock,
plug the mainframe power cord into a properly wired receptacle where earth
ground has been verified by a qualified service person.
Without the protective ground connection, all parts of the VXOA41 are potential
shock hazards. This includes knobs and controls that may appear to be insulators.
Use only the power cord and connector specified for your VXI mainframe. Use
only a power cord that is in good condition.
To avoid fire hazard, use only the fuse specified in the parts list for your VXI
mainframe and that is identical in type, voltage rating, and current rating.
To avoid personal injury, do not operate the VXOA41 or VXI mainframe without
the panels or covers.
The VXOA41 provides no explosion protection from static discharges or arcing
components. Do not operate the VXOA41 in an atmosphere of explosive gasses.
Optical Output
Power Source
Grounding the VXOA41
Use the Proper Power
Cord
User the Proper Fuse
Do Not Remove Covers or
Panels
Do Not Operate in
Explosive Atmospheres

Getting Started

VXOA41 Optical Attenuator User Manual 1–1
Getting Started
Congratulations on your purchase of a VXOA41 Optical Attenuator. The
VXOA41 Optical Attenuator is a high-performance instrument used to attenuate
optical signals. Some of the outstanding characteristics of the VXOA41 are:
Attenuation to 60 dB — the VXOA41 can attenuate signals up to 60 dB in
steps of 0.01 dB. A shutter provides greater than 100 dB attenuation.
600 nm to 1700 nm calibrated spectral response in one unit.
Linear response within ±0.05 dB.
Ability to store attenuation levels, which is useful for repeat measurements.
Versions available for both single and multimode fiber.
VXI double-wide C-size module with message-based interface.
The VXOA41 is a message-based VXI module. Control communications are
provided at two levels: low-level word serial commands and ASCII commands.
Low-level word serial commands provide system administration services. Word
serial commands are used by the VXI Resource Manager to determine system
status, allocate resources, and initiate normal system operation. These commands
are not normally accessed by the system user.
The ASCII command set is used for instrument control and communication. The
commands use IEEE Std 488.2 style syntax. Word serial protocol transports
these communications between the system controller or slot 0 (if the system
controller is not included in the VXI mainframe) and the instrument module.
First Time Operation
Before operating the VXOA41 for the first time, you must perform the following
steps:
1. Verify that you have met the power and cooling requirements for the VXI
mainframe with the VXOA41 installed.
NOTE. There is a label located on the right-side shield that lists the power and
cooling requirements.
2. Verify that the backplane jumpers have been properly set up for the desired
slot in the mainframe; if necessary, refer to the installation instructions later
in this section.

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1–2 VXOA41 Optical Attenuator User Manual
3. Ensure that you have the logical address switches on the VXOA41 set to the
desired address (see Figure 1-1).
4. Ensure that the VXOA41 is properly installed in the VXI mainframe.
5. Verify that you can communicate with the VXI module as described in the
Checkout Procedure.
Installation
After unpacking all components, inspect them for any damage that may have
occurred due to shipping.
You can install the VXOA41 into any appropriate C- or D-size VXI mainframe
in slots 1–12. Verify that the mainframe can provide adequate power and cooling
for the module. Table 1–1 lists the VXOA41 power requirements. The power and
cooling requirements are also labeled on the VXOA41 side cover as well as in
Specifications later in this manual.
Table 1–1: VXOA41 Module Power Requirements
Voltage Average Current MaximumCurrent
+24 V 72 mA 320 mA
–24 V 31 mA 40 mA
+12 V N/A N/A
–12 V N/A N/A
+5 V 2.1A 2.3A
–5.2 V 34 mA 50 mA
–2 V 30 mA 680 mA
WARNING. Shock hazards exist due to high currents within the mainframe
compartment. Do not configure the Bus Grant and Interrupt Acknowledge
jumpers unless you are technically qualified to do so.
Before installing the VXOA41 in a VXI mainframe, a technically qualified
person should verify that the slot where you intend to install the module has the
Bus Grant (BG0–BG3) and Interrupt Acknowledge (IACK) jumpers properly
installed for the mainframe slot. The VXI mainframes contain daisy-chain
jumpers for these signals. The jumpers must be configured for the VXOA41 so
that the slot is not bypassed.
The VXOA41 is a 2-wide VXI slot instrument. The left slot will pass on
daisy-chained IACK signals to the right, but the right slot of the VXOA41 will

Getting Started
VXOA41 Optical Attenuator User Manual 1–3
not pass IACK signals because it does not connect to the backplane. Thus, the
mainframe slot that accepts the right side of the VXOA41 must have jumpers
installed to pass on IACK signals.
Use the following procedures to install the VXOA41 into a Tektronix main-
frame. If you use the VXOA41 with another mainframe, you may have to modify
this procedure.
CAUTION. Some components on the VXOA41 are susceptible to static-discharge
damage. Observe standard handling precautions for static-sensitive devices.
Always wear a grounded wrist strap, or equivalent, while installing or removing
the VXOA41
1. The VXOA41 contains a DIP switch that you use to set the module address
within the mainframe. Figure 1-1 shows the switch location. The switch can
be accessed through the hole in the side panel. Set the switch to the desired
address before installing the VXOA41 in the mainframe.
If the system resource manager supports Dynamic Auto Configure, you can
set the switch to 255 (FF). At power-on, the logical address will automatical-
ly be configured. For proper operation, the logical address must be unique in
the VXI system. In other words, no two modules in the VXI system can have
the same logical address.
Installing the VXOA41 in a
VXI Mainframe

Getting Started
1–4 VXOA41 Optical Attenuator User Manual
ON (1)
(When Down)
LSB
OFF (0)
(When Down)
MSB
Rectangular hole
in right side shield
1 2 3 4 5 6 7 8
OPEN
Figure 1-1: Logical Address Switch location on the VXOA41
2. Ensure that the rear-panel power ON/OFF switches and the front-panel
ON/STANDBY switch on the mainframe are in the OFF and STANDBY
positions, respectively.
CAUTION. If you install the VXOA41 in a D-size mainframe, make sure that you
connect the P1 and P2 connectors of the module to the P1 and P2 connectors of
the mainframe. Connecting the P1 and P2 connectors of the module to the P2
and P3 connectors of the mainframe can severely damage the VXOA41 or the
mainframe.
3. Carefully insert the module into the mainframe top and bottom guides in the
slots where you plan to install the module, and push the module into the
mainframe as far as it will go without forcing it. This should seat the P1 and
P2 connectors.

Getting Started
VXOA41 Optical Attenuator User Manual 1–5
NOTE. If the VXOA41 is installed in a D-size mainframe, ensure that the
front-panel gap is properly sealed to maintain adequate internal air flow for
cooling.
4. Ensure the module is fully seated into its VXI connectors and that the front
panel of the module is flush with the front of the mainframe chassis. Tighten
the module retainer screws at the top and bottom of the front panel to secure
the module in the mainframe.
Use the following steps to remove the VXOA41 from a Tektronix mainframe. If
you use the VXOA41 with another mainframe, you may have to modify this
procedure.
1. Ensure that the rear-panel power ON/OFF switches and the front panel
ON/STANDBY switch on the mainframe are in the OFF and STANDBY
positions, respectively.
2. Loosen the module retainer screws.
3. Grasp both handles of the module and pull the module straight out of the
mainframe as shown in Figure 1-2.
Figure 1-2: Removing the VXOA41 from the Mainframe
4. Once the module has been removed, store it in a static-free environment.
Removing the VXOA41
from a VXI Mainframe

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1–6 VXOA41 Optical Attenuator User Manual
Checkout Procedure
Once you have installed the VXOA41 in a VXI mainframe, you can communi-
cate with it as with any other VXI module. You do not need any special software
installed. However, because you are working in a VXI environment, this
procedure assumes that you have the capability to communicate with the
VXOA41 using standard talker/listener hardware or software or other program
development environments.
There are basically two steps that you should perform to verify that the VXOA41
is correctly installed and operating on the VXI bus.
1. Verify that the READY LED is lighted approximately five seconds after you
power on the mainframe; this LED verifies that the power-up diagnostics
have passed.
2. After the diagnostics have passed, you can verify that the VXOA41
communicates with a controller or commander by issuing *IDN? to the
VXOA41 and reading the results. If the VXOA41 properly responds to ID?
or *IDN?, you have verified the communications with the module on the
VXI bus. In general, the VXOA41 should respond to an ID? as follows:
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Operating Basics