Tektronix VXOA41 Manual
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User Manual
VXOA41
Optical Attenuator
070-8777-01
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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.
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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.
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
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Table of Contents
List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
iii
iv
v
Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1–1
First Time Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checkout Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1–1
1–2
1–6
Operating Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–1
Front-Panel Indicators and Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2–1
Command Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–1
Clearing the VXOA41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Command and Query Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Command Entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Argument Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Syntax Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–1
3–1
3–3
3–5
3–7
Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–9
Common Commands and Queries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Device Commands and Queries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ADJusting? (Query Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ALLev? (Query Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ATTenuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ATTenuation:INCRement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ATTenuation:NEXT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ATTenuation:TRIGger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ATTenuation:TPOLarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BLRN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*CAL? (Query Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*CLS (No Query Form) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DESE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DISable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*ESE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*ESR? (Query Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EVENt? (Query Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EVMSg? (Query Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EVQTy? (Query Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FACTory (No Query Form) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
HEADer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*IDN? (Query Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*LRN? or SET? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–9
3–11
3–11
3–12
3–13
3–14
3–14
3–15
3–16
3–16
3–17
3–17
3–18
3–19
3–19
3–20
3–21
3–21
3–22
3–22
3–24
3–24
3–25
Getting Started
Operating Basics
Reference
VXOA41 Optical Attenuator User Manual
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i
Table of Contents
*OPC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*OPT? (Query Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*PSC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
RECall (No Query Form) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REFerence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*RST (No Query Form) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*SRE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*STB? (Query Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
STORe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*TST? (Query Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VERBOSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
*WAI (No Query Form) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WAVelength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–26
3–26
3–27
3–27
3–28
3–28
3–29
3–30
3–31
3–31
3–32
3–33
3–33
Status and Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–35
Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Queues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Event Handling Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Conflicts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3–35
3–39
3–39
3–40
3–41
Appendix A: Accessories and Options . . . . . . . . . . . . . . . . . . . . . . . . . .
A–1
Standard Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A–1
A–1
A–2
Appendix B: Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix C: Interface Specifications . . . . . . . . . . . . . . . . . . . . . . . . . .
B–1
C–1
Interface Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Character Set (ASCII Chart) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VXI Word Serial Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
C–1
C–2
C–3
Appendix D: Using the *OPC Query/Command . . . . . . . . . . . . . . . . .
Appendix E: Packing for Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendix F: Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
D–1
E–1
F–1
Cleaning the Optical Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing the Optical Port Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
F–1
F–2
Appendix G: Performance Verification . . . . . . . . . . . . . . . . . . . . . . . . .
G–1
Equipment List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Panel LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shutter Attenuation and Disable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Insertion Loss (Long Wavelengths) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Insertion Loss (Short Wavelengths) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repeatability and Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
G–1
G–3
G–3
G–5
G–7
G–9
G–11
Appendix H: Replaceable Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
H–1
Parts Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using the Replaceable Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
H–1
H–1
Appendices
Glossary and Index
ii
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Table of Contents
List of Figures
Figure 1-1: Logical Address Switch location on the VXOA41 . . . . . .
Figure 1-2: Removing the VXOA41 from the Mainframe . . . . . . . . .
Figure 2-1: VXOA41 Front Panel (Option 1 Shown) . . . . . . . . . . . . . .
Figure 3-1: Command Message Elements . . . . . . . . . . . . . . . . . . . . . . .
Figure 3-2: Block Argument Example . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3-3: Typical Syntax Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3-4: The Standard Event Status Register (SESR) . . . . . . . . . .
Figure 3-5: The Status Byte Register (SBR) . . . . . . . . . . . . . . . . . . . . .
Figure 3-6: The Device Event Status Enable Register (DESER) . . . .
Figure 3-7: The Event Status Enable Register (ESER) . . . . . . . . . . . .
Figure 3-8: The Service Request Enable Register (SRER) . . . . . . . . .
Figure 3-9: Status and Event Handling Process . . . . . . . . . . . . . . . . . .
Figure F-1: Removing the Optical Bulkhead Connector . . . . . . . . . . .
Figure F-2: FC Optical Bulkhead Assembly . . . . . . . . . . . . . . . . . . . . .
Figure F-3: ST Optical Bulkhead Assembly . . . . . . . . . . . . . . . . . . . . .
Figure F-4: DIN 47256 Optical Bulkhead Assembly . . . . . . . . . . . . . .
Figure F-5: SC Optical Bulkhead Assembly . . . . . . . . . . . . . . . . . . . . .
Figure G-1: Setup for Shutter Attenuation and Disable Procedure . .
Figure G-2: First setup for Insertion Loss Procedure . . . . . . . . . . . . .
Figure G-3: Second setup for Insertion Loss Procedure . . . . . . . . . . .
Figure G-4: First setup for Insertion Loss Procedure . . . . . . . . . . . . .
Figure G-5: Second setup for Insertion Loss Procedure . . . . . . . . . . .
Figure G-6: Setup for Repeatability and Accuracy Procedure . . . . . .
Figure H-1: VXOA41 Replaceable Parts . . . . . . . . . . . . . . . . . . . . . . .
VXOA41 Optical Attenuator User Manual
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1–4
1–5
2–2
3–2
3–6
3–7
3–36
3–36
3–37
3–38
3–38
3–40
F–2
F–3
F–4
F–4
F–5
G–5
G–7
G–8
G–9
G–10
G–11
H–4
iii
Table of Contents
List of Tables
Table 1–1: VXOA41 Module Power Requirements . . . . . . . . . . . . . . .
Table 3–1: BNF Symbols and Meanings . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–2: Command Message Elements . . . . . . . . . . . . . . . . . . . . . . .
Table 3–3: Comparison of Header On and Off Responses . . . . . . . . .
Table 3–4: Block Argument Elements . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–5: Numeric Argument Descriptions . . . . . . . . . . . . . . . . . . . .
Table 3–6: Commands Common to All GPIB Devices and Supported
by the VXOA41 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–7: VXOA41 Device Commands and Parameters . . . . . . . . .
Table 3–8: FACTory Default Settings . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–9: Results from *TST? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–10: SESR Bit Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–11: SBR Bit Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–12: No Event Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3–13: Command Error Messages — CME Bit 5 . . . . . . . . . . . .
Table 3–14: Execution Error Messages — EXE Bit 4 . . . . . . . . . . . . .
Table 3–15: Device Error Messages — DDE Bit 3 . . . . . . . . . . . . . . .
Table 3–16: System Event Messages — QYE Bit 2 . . . . . . . . . . . . . . .
Table 3–17: Execution Warning Messages — EXE Bit 4 . . . . . . . . . .
Table B–1: Optical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table B–2: Physical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table B–3: Environmental Performance . . . . . . . . . . . . . . . . . . . . . . .
Table B–4: Certifications and Compliances . . . . . . . . . . . . . . . . . . . . .
Table C–1: The ASCII Character Set . . . . . . . . . . . . . . . . . . . . . . . . . .
iv
1–2
3–1
3–2
3–3
3–5
3–6
3–10
3–11
3–23
3–32
3–36
3–37
3–41
3–41
3–42
3–43
3–43
3–44
B–1
B–2
B–2
B–3
C–2
VXOA41 Optical Attenuator User Manual
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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
Protective ground
(earth) terminal
ATTENTION
Refer to manual
VXOA41 Optical Attenuator User Manual
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v
Safety Summary
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.
Optical Output
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.
Power Source
Grounding the VXOA41
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 documentation. 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 the Proper Power
Cord
Use only the power cord and connector specified for your VXI mainframe. Use
only a power cord that is in good condition.
User the Proper Fuse
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.
Do Not Remove Covers or
Panels
Do Not Operate in
Explosive Atmospheres
vi
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.
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Getting Started
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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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1–1
Getting Started
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
Maximum Current
+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
2.1 A
2.3 A
–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
1–2
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Getting Started
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.
Installing the VXOA41 in a
VXI Mainframe
Use the following procedures to install the VXOA41 into a Tektronix mainframe. 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 automatically 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.
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Getting Started
OPEN
MSB
ON (1)
(When Down)
1 2 3 4 5 6 7 8
LSB
OFF (0)
(When Down)
Rectangular hole
in right side shield
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.
1–4
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Getting Started
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.
Removing the VXOA41
from a VXI 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.
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Getting Started
Checkout Procedure
Once you have installed the VXOA41 in a VXI mainframe, you can communicate 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:
1–6
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Operating Basics
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Operating Basics
This section provides a brief description of the indicators and connectors of the
VXOA41 Optical Attenuator.
Front-Panel Indicators and Connectors
The VXOA41 front-panel indicators and connectors consist of five LEDs (light
emitting diodes) and two connectors as shown in Figure 2-1.
Two of the front-panel LEDs show the module status. The READY LED is a
green LED that lights when the power-on diagnostics have successfully
completed. If the diagnostics fail, the READY LED will not light.
The ACCESSED LED is an amber LED that briefly lights each time communications to the VXOA41 occur. It also lights while the MODID is asserted by
the VXI Slot 0 module. This feature supports physical identification of modules
within the mainframe.
The ATT ADJ LED is a red LED that lights when the attenuation is being
changed. When it is dark, the requested attenuation level has been achieved.
The MIN ATT LED is a red LED that lights when the attenuation level has been
set to the minimum level.
The DISABLE LED is a red LED that lights when the internal shutter has moved
across the optical path. Maximum attenuation is acheived when the internal
shutter blocks the optical path.
The two connectors on the front panel are FC-PC style connectors. The top
connector is for the signal input; the lower connector is for the attenuated output
signal.
NOTE. See Appendix F for instructions on how to change the optical connectors
to another style, such as ST or DIN 47256.
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.
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2–1
Operating Basics
Figure 2-1: VXOA41 Front Panel (Option 1 Shown)
2–2
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Reference
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Command Syntax
You can control the VXOA41 using a large group of commands and queries.
This section describes the syntax these commands and queries use and the
conventions the VXOA41 uses to process them. The commands and queries
themselves are listed in the section entitled Commands.
You transmit commands to the VXOA41 using the enhanced American Standard
Code for Information Interchange (ASCII) character encoding. Appendix C
includes a chart of the ASCII character set.
This manual uses Backus-Naur Form (BNF) notation and syntax diagrams to
describe commands and queries. The syntax diagrams follow the notations and
conventions of the ANSI/IEEE Std 488.2-1987, section 7.2.
This manual uses the BNF symbols listed in Table 3–1.
Table 3–1: BNF Symbols and Meanings
Symbol
Meaning
Defined element
Is Defined As
Exclusive OR
Group; one element is required
Optional; can be omitted
Previous element(s) may be repeated
Comment
Clearing the VXOA41
You can stop any query or process by using the Clear VXI Word Serial command.
Command and Query Structure
Commands consist of set commands and query commands (usually simply called
commands and queries). Commands modify instrument settings or tell the
VXOA41 to take a specific action. Queries cause the VXOA41 to return
information about its status.
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3–1
Command Syntax
Most commands have both a set form and a query form. The query form of the
command is the same as the set form but with a question mark on the end. For
example, the set command ATT:DB has a query form ATT:DB?. Not all commands
have both a set and query form; some commands are set only and some are query
only.
A command message is a command or query name, followed by any information
the VXOA41 needs to execute the command or query. Command messages
consist of three different element types, defined in Table 3–2 and shown in the
example in Figure 3-1.
Table 3–2: Command Message Elements
Symbol
Meaning
<Header>
The basic command name. If the header ends with a question mark,
the command is a query. The header may begin with a colon (:)
character; if the command is concatenated with other commands the
beginning colon is required. The beginning colon can never be used
with command headers beginning with star (*).
<Mnemonic>
A header sub-function. Some command headers have only one
mnemonic. If a command header has multiple mnemonics, they are
always separated from each other by a colon (:) character.
<Argument>
A quantity, quality, restriction, or limit associated with the header. Not
all commands have an argument, while other commands have multiple
arguments. Arguments are separated from the header by one or more
space characters. Arguments are separated from each other by a
<Separator>, which is defined below.
<Separator>
A separator between arguments of multiple-argument commands. The
separator can be a single comma, or it may optionally have white
space characters before and after the comma.
Header
ATT:DB 10
Mnemonics
Argument
Figure 3-1: Command Message Elements
Commands
Commands cause the VXOA41 to perform a specific function or change one of
its settings. Commands have the following structure:
[:]<Header>[<Space><Argument>[<Separator><Argument>]...]
3–2
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Command Syntax
Queries
Queries cause the VXOA41 to return information about its status or settings.
Queries have the structure:
!
!
!#"
!"!
!#"
You may use only a part of the header in a query command. When you do this,
the instrument returns information about all the possible mnemonics that you
have left unspecified. For example, returns the current setting in
absolute dB units, while returns the setting in absolute units and units
relative to the reference as well as all other parameters.
Headers in Query
Responses
You can control whether or not headers are returned by the VXOA41 as part of
the query response. Use the command to control this feature. If is on, command headers are returned as part of the query, and the query response
is formatted as a valid set command. When is off, only the values are
sent back in the response, which may be easier to parse and to extract information from. Table 3–3 shows the difference in responses.
NOTE. Command queries that begin with an asterisk never return a header in the
response (per IEEE 488.2).
Table 3–3: Comparison of Header On and Off Responses
Query
Header Off Response
Header On Response
Command Entry
When sending commands to the VXOA41, keep the following in mind:
You can enter commands in uppercase or lowercase.
Precede all commands with blank characters. Blank characters include any
combination of the ASCII control characters 00 through 09 and 0B through
20 hexadecimal (0 through 9 and 11 through 32 decimal).
The VXOA41 ignores commands consisting of any combination of blank
characters, carriage returns, and line feeds.
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Command Syntax
Abbreviating Commands
You can abbreviate many VXOA41 commands. These abbreviations are shown
in capitals in the command’s listing in the Commands section. For example, the
command DISPlay can be entered simply as DISP or display.
If you use the HEADER command to have command headers included as part of
query responses, you can further control whether the returned headers are
abbreviated or are full-length. The Verbose command lets you control this.
Concatenating Commands
You can concatenate any combination of set commands and queries using a
semicolon (;). The VXOA41 executes concatenated commands in the order
received. Concatenating commands is useful when you want to avoid events
generated by conflicting settings — see Conflicts on page 3–40.
When concatenating commands and queries you must follow these rules:
1. Completely different headers must be separated by both a semicolon and by
the beginning colon on all commands but the first. For example, the
commands ATT:DB 15 and DISABLE OFF would be concatenated into a
single command:
ATT:DB 15;:DIS OFF
2. Never precede a star (*) command with a colon:
ATT:DB 10;*OPC
3. When you concatenate queries, the responses to all the queries are concatenated into a single response message. For example, if the disable mode is
OFF and the attenuator is 20 dB, the concatenated query:
DIS?;:ATT:DB?
will return either DIS 0;:ATT:DB 20 if HEADER is set to ON or 0;20 if
HEADER is set to OFF.
4. Set commands and queries may be concatenated in the same message. For
example,
ATT:DB 15;DIS ON;DIS?;:ADJ?
is a valid message that sets the attenuation to 15 dB, the disable mode to
ON, and responds with the disable status and the adjusting status. Concatenated commands and queries are executed in the order received.
Here are some invalid concatenations:
3–4
DISABLE OFF;ATT:DBR 5
No colon before ATT
ATT:MIN;:*OPC
Extra colon before a star (*) command
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Command Syntax
Message Terminators
This manual uses <EOI> (End of Input) to represent a message terminator.
In VXI byte transfer protocol, the EOI is represented as being bit 8 of the Byte
Available and Byte Request word serial commands. If bit 8 is set, then EOI is
associated with the current data byte for that word serial command. When using
VXI byte transfer protocol, the VXOA41 always accepts the EOI interface
symbol as an input message terminator.
The end-of-message terminator may be either the END message (EOI asserted
concurrently with the last data byte), the ASCII code for line feed (LF) sent as
the last data byte, or both.
The end-of message terminator should not immediately follow a semicolon (;).
The VXOA41 always terminates responses to queries with linefeed and EOI
asserted.
Argument Types
The argument of a command can take several forms. The individual descriptions
of each command tell which argument types to use with that command.
Block Arguments
One VXOA41 command utilizes a block argument form. The elements of the
block arguments described in Table 3–4.
Table 3–4: Block Argument Elements
Symbol
Meaning
<Block>
A block of data bytes, which is defined below
<NZDig>
A non-zero digit character, in the range 1–9
<Dig>
A digit character, in the range 0–9
<DChar>
A character with the binary equivalent of 0 through FF hexadecimal (0
through 255 decimal)
The block argument is in the following format:
<Block> ::= #<NZDig><Dig>[<Dig>. . .][<DChar>. . .]
<NZDig> specifies the number of <Dig> elements that follow. Taken together, the
<Dig> elements form a decimal integer that specifies how many <DChar>
elements follow. See Figure 3-2.
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3–5
Command Syntax
Block Argument
BLRN #222(binary data - 22 bytes)
Block Header
Specifies Data Length
Specifies Number of
Length Digits that Follow
Figure 3-2: Block Argument Example
The block argument can also take the following format:
<Block> ::= #0[<DChar>. . .]<EOI>
Under IEEE Std 488.2 the above format is also a valid form for block arguments.
If this form is used, the last byte of the block must have EOI asserted. Consequently, this must be the last or only command. Although the VXOA41 accepts
this format, it will never respond to a query with this format.
Numeric Arguments
Many VXOA41 commands require numeric arguments. Descriptions of these
arguments are given in Table 3–5.
Table 3–5: Numeric Argument Descriptions
3–6
Symbol
Meaning
<NR1>
Signed integer value
<NR2>
Floating point value without an exponent
<NR3>
Floating point value with an exponent
<NRf>
Flexible numeric argument {NR1|NR2|NR3}. A suffix composed of a
multiplier (letter exponent) and units may be used as an alternate to
NR3. For example, this numeric type would let you use “10nm” as an
alternate to “10E–9m”.
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Command Syntax
Syntax Diagrams
The syntax diagrams in this manual use the following symbols and notation:
Circles and ovals contain literal elements that must be sent exactly as shown.
Command and query names are abbreviated to the minimum required
spelling.
Boxes contain the defined elements described earlier in this section, such as
or .
Arrows connect the elements and show the allowed paths through the
diagram. Parallel paths show that one and only one of the paths must be
taken. A path around a group of elements shows that those elements are
optional. Loops show elements that can be repeated.
Figure 3-3 shows the structure of a few typical syntax diagrams.
Figure 3-3: Typical Syntax Diagrams
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3–7
Command Syntax
3–8
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Commands
VXOA41 commands fall into two main groups: Common Commands and
Device Commands. The commands follow Tektronix Standard Codes and
Formats 1991.
Most of these commands can be used either as set commands or queries.
However, some commands can only be used to set: these have the words “No
Query Form” included with the command name. Other commands can only be
used to query: these have a question mark appended to the header, and include
the words “Query Only” in the command name.
Headers, mnemonics, and arguments are usually spelled out fully in text, with
the minimum required spelling shown in upper case. For example, to use the
command you must enter at least . The examples in this manual use
the abbreviated forms.
Common Commands and Queries
Several commands and queries used with the VXOA41 are common to all
devices that support IEEE 488.2. These commands and queries are defined by
IEEE Std 488.2-1987.
Table 3–6 lists the Common Commands supported by the VXOA41. Complete
descriptions of these commands appear in an alphabetical listing of commands
later in this section.
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3–9
Commands
Table 3–6: Commands Common to All GPIB Devices and Supported by the
VXOA41
Header
Full Command Name
All Events
Binary Device Setup
1
Instrument Self Calibration
Clear Status
Device Event Status Enable
Standard Event Status Enable
Standard Event Status Register
Event
Event Message
Number of Events in Queue
Set to Factory Defaults
Header
Identification
Learn Device Setup
Operation Complete
Option Identification Query
Power-On Status Clear
Reset
Service Request Enable
Read Status Byte
Self-Test
Verbose
Wait To Continue
1
3–10
*CAL? always returns 0.
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Commands
Device Commands and Queries
Table 3–7 lists the device commands, queries, and command parameters that are
specific to the VXOA41. Complete descriptions of these commands appear in
the alphabetical listing of commands that immediately follows this table.
Table 3–7: VXOA41 Device Commands and Parameters
Header
Full Command Name
'%&"
Attenuator Adjusting
"'&#"
Attenuation
"'&#"
Attenuation in Absolute Terms
"'&#"
Attenuation with Reference Value
"'&#"
Minimum Attenuation
"'&#"!"&
Attenuation Increment
"'&#"
Command Trigger
"'&#"$
VXI Trigger Output
"'&#"$&(
VXI Trigger Output Polarity
Light Shutter Status
Recall Attenuation Setting
$"
Reference
)
Store Attenuation
"&
Wavelength
ADJusting? (Query Only)
The ADJusting? query returns the status of the attenuator. A 1 is returned if the
attenuator is moving to some attenuation value. A 0 is returned if the attenuator
is stationary.
Related Commands
Syntax
*OPC, *WAI
'%&"
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3–11
Commands
ADJusting
Syntax
?
ADJ?
Would return the string ":ADJUSTING 0" or ":ADJUSTING 1".
ALLev? (Query Only)
The ALLev? query causes the VXOA41 to return all events and their messages.
This query also removes the returned events from the Event Queue. The
messages are separated by commas. Use the *ESR? query to enable the events to
be returned. For a complete discussion of the use of these registers, see
page 3–35. This command is similar to repeatedly sending EVMsg? queries to
the VXOA41.
Related Commands
Syntax
*CLS, DESE, *ESE, *ESR?, EVENT?, EVMsg?, EVQTY, *SRE, *STB?
ALLev?
ALLev
Returns
?
The event code and message in the following format:
<Event Code><Comma><QString>[<Event Code><Comma><QString>...]
<QString>::= <Message>;[<Command>]
<Command> is the command that caused the error and it might be returned when a
command error is detected by the VXOA41. As much of the command will be
returned as possible without exceeding the 60 character limit of the <Message>
and <Command> strings combined. The command string is right-justified.
Examples
ALLev?
Might return the string:
401,"Power on"
ALLev?
Would return a string similar to the following if an unrecognized command
were sent to the VXOA41:
113,"Undefined header; unrecognized commandĆabc".
3–12
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Commands
ATTenuation
ATTenuation can be used as both a query and as a command to set device
parameters. ATTenuation has three parameters: DB, DBR, and MIN. Use the DB
term to query or set attenuation in absolute terms relative to minimum attenuation. To query or set attenuation values relative to the REFerence value, use the
DBR term. To set the attenuation to the minimum (0 dB), use the MIN term.
NOTE. Attenuation can be changed even if the light shutter is closed.
Related Commands
Syntax
STORe, RECall
Arguments
Examples
If you make a query without an argument (for example, ATTen?), the response is
the same as that for an ATTen:DB?; DBR? query.
Would return the string :
! !! "!
Would return the string:
! !! "
Would return the string:
! !# VXOA41 Optical Attenuator User Manual
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3–13
Commands
ATTenuation:INCRement
ATTenuation:INCRement sets and queries the increment value used in the
triggered auto-increment mode. Each time a trigger occurs (a trigger word serial
command or the ATT:NEXT command) the VXOA41 changes the current
attenuation setting by the set increment value. The increment value may be either
positive or negative.
NOTE. Attenuation can be changed even if the light shutter is closed.
Related Commands
Syntax
ATTenuation:NEXT
Arguments
Examples
The argument has a range of –60 to +60. The minimum increment is 0.1. Setting
the increment to –0.01 < value < 0.01 disables the auto-increment feature.
Would return the string:
Sets the auto-increment value to 5.0 dB.
ATTenuation:NEXT
ATTenuation:NEXT causes the VXOA41 to change the current attenuation
setting by the current auto-increment value.
NOTE. Attenuation can be changed even if the light shutter is closed.
Related Commands
3–14
ATTenuation:INCRement
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Commands
Syntax
ATTen:NEXT
ATTen
:
NEXT
ATTenuation:TRIGger
The ATTenuation:TRIGger command controls the usage of a VXI TTL trigger
line in monitoring the attenuator adjusting status. When a trigger line is selected,
the associated trigger line will be asserted or unasserted when the attenuator is
busy adjusting (attenuation is not stable). The polarity of the trigger signal is
determined by the ATTenuation:TPOLarity command. The desired TTL trigger
line is specified as TTLTRG0 through TTLTRG7. To disable the TTL trigger
line usage, use the command ATTenuation:TRIGger NONE.
Related Commands
Syntax
ATTenuation:TPOLarity
ATTen:TRIGger { TTLTRG<NR1> | NONE }
ATTen:TRIGger?
<space>
ATTen
:
Examples
<NR1>
NONE
TRIGger
Arguments
TTLTRG
?
The numeric argument has a range of 0 to 7. That is, TTLTRG<NR1> can take
on the values TTLTRG0, TTLTRG1, . . . TTLTRG7. Note that there is no space
between TTLTRG and the numeric argument.
ATT:TRIG TTLTRG1
Specifies that the line TTLTRG1 will be used to monitor attenuator adjusting
status.
ATT:TRIG NONE
Disables the TTL trigger line usage.
ATT:TRIG?
Might return the string:
ATTENUATION:TRIGGER TTLTRG7
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3–15
Commands
ATTenuation:TPOLarity
The ATTenuation:TPOLarity command sets the polarity of the VXI TTL trigger
line used to monitor the attenuator adjusting status.
Related Commands
Syntax
ATTenuation:TRIGger
ATTen:TPOLarity { 0 | 1 }
ATTen:TPOLarity?
0
<space>
ATTen
:
TPOLarity
1
?
Arguments
The numeric argument can be either 0 or 1. When the argument is 0, the trigger
line specified with the ATT:TRIG command is asserted when the attenuator is
busy adjusting and unasserted when the attenuator is stable. If the argument is 1,
the trigger line will be unasserted when the attenuator is busy adjusting and
asserted when it is stable.
Examples
ATT:TPOL 0
Sets the polarity of the TTL trigger line so that the line is asserted when the
attenuator is busy.
ATT:TPOL
Might return the string:
ATTENUATION:TPOLARITY 1
BLRN
The query version of this command reads the instrument configuration in binary
form. The command version configures the instrument binary data format. The
configuration is 22 bytes long.
Related Commands
Syntax
*LRN
BLRN <Block>
BLRN?
3–16
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Commands
<Space>
<Block>
BLRN
?
Examples
BLRN?
Might return the response:
BLRN #222 <22 bytes of binary data>
*CAL? (Query Only)
This command query returns a number that denotes the calibration status of the
VXOA41. If the *CAL? query returns 0, then calibration is OK. If a non-zero
value is returned, the unit needs to be returned to Tektronix for calibration.
Related Commands
*TST?
Syntax
*CAL?
*CAL
Examples
?
*CAL?
Wil normally return "0".
*CLS (No Query Form)
The *CLS (Clear Status) command clears the VXOA41 status data structures.
This command also puts the VXOA41 in the Operation Complete Command Idle
State and in the Operation Complete Query Idle State. While in these states, the
VXOA41 has nothing in its buffers and does not execute commands or queries.
Related Commands
Syntax
DESE, *ESE, *ESR, EVENT?, EVMSG?,*SRE, *STB
*CLS
*CLS
The *CLS command clears
the Event Queue
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3–17
Commands
the Standard Event Status Register (SESR)
the Status Byte Register (except the MAV bit; see below)
If the *CLS command immediately follows an <EOI>, the output queue and
MAV bit (Status Byte Register bit 4) are also cleared. MAV indicates information is in the output queue. DCL will clear the output queue and thus MAV.
*CLS does not clear the output queue or MAV. (A complete discussion of these
registers and bits and of event handling in general is on page 3–35.)
DESE
The DESE (Device Event Status Enable) command sets and queries the bits in
the Device Event Status Enable Register (DESER). The DESER prevents events
from being reported to the Standard Event Status Register (SESR) and from
being entered into the Event Queue. For a complete discussion of the use of
these registers, see page 3–35.
Related Commands
Syntax
*CLS, *ESE, *ESR, EVENT?, EVMSG?, *SRE, *STB
DESE <NRf>
DESE?
<Space>
<NRf>
DESE
?
Arguments
<NRf> is a value in the range from 0 to 255. The binary bits of the DESER are
set according to this value. For example, DESE 209 sets the DESER to the binary
value 11010001 (that is, the first bit in the register is set to 1, the second bit to 1,
the third bit to 0, etc.).
The power-on default for DESER is all bits set if *PSC is 1. If *PSC is 0, the
DESER maintains its value through a power cycle.
NOTE. Setting the DESER and the ESER to the same value allows only those
codes to be entered into the Event Queue and summarized on the ESB bit (bit 5)
of the Status Byte Register. Use the *ESE command to set the ESER. A complete
discussion of event handling is on page 3–35.
3–18
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Commands
Examples
Sets the DESER to binary 11010001, which enables the PON, URQ, EXE,
and OPC bits.
Might return the string , showing that the DESER contains the
binary value 10111010.
DISable
To query or set the status of the light shutter, use the DISable term. A DISable
argument of 1, or ON, closes the light shutter and blocks all light through the
fiber ports. A DISable argument of 0, or OFF, opens the shutter and allows light
to pass through the fiber ports (light will be attenuated at the level specified by
the ATTEN:DB or ATTEN:DBR terms).
Related Commands
Syntax
N/A
Examples
Returns the string:
if the light shutter is not closed.
*ESE
The *ESE (Event Status Enable) command sets and queries the bits in the Event
Status Enable Register (ESER). The ESER prevents events from being reported
to the Status Byte Register (STB). For a complete discussion of the use of these
registers, see page 3–35.
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3–19
Commands
Related Commands
Syntax
*CLS, DESE, *ESR, EVENT?, EVMSG? *SRE, *STB
*ESE <NRf>
*ESE?
<Space>
<NRf>
*ESE
?
Arguments
<NRf> is a value in the range from 0 through 255. The binary bits of the ESER
are set according to this value.
The power-on default for ESER is 0 if *PSC is 1. If *PSC is 0, the ESER
maintains its value through a power cycle.
NOTE. Setting the DESER and the ESER to the same value allows only those
codes to be entered into the Event Queue and summarized on the ESB bit (bit 5)
of the Status Byte Register. Use the DESE command to set the DESER. A complete
discussion of event handling is on page 3–35.
Examples
*ESE 209
Sets the ESER to binary 11010001, which enables the PON, URQ, EXE, and
OPC bits.
*ESE?
Might return the string *ESE 186, showing that the ESER contains the
binary value 10111010.
*ESR? (Query Only)
The *ESR? (Event Status Register) query returns the contents of the Standard
Event Status Register (SESR). *ESR? also clears the SESR (since reading the
SESR clears it). For a complete discussion of the use of these registers, see page
3–35.
Related Commands
Syntax
3–20
ALLev?, *CLS, DESE, *ESE, EVENT?, EVMSG?, EVQTy?, *SRE, *STB
*ESR?
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Commands
Examples
Might return the value , showing that the SESR contains binary
11010101.
EVENt? (Query Only)
The EVENt? query returns from the Event Queue an event code that provides
information about the results of the last *ESR? read. EVENT? also removes the
returned value from the Event Queue. Note that the ALLev? command removes
all pending events from the event queue and places them in the output queue. A
complete discussion of event handling is on page 3–35.
Related Commands
Syntax
ALLev?, *CLS, DESE, *ESE, *ESR?, EVMSG?, EVQty?, *SRE, *STB
Examples
Might return the response , showing that there was an error in a
command header.
EVMSg? (Query Only)
The EVMSg? query removes from the Event Queue a single event code
associated with the results of the last *ESR? read and returns the event code
along with an explanatory message. A complete discussion of event handling is
on page 3–35.
Related Commands
Syntax
*CLS, DESE, *ESE, *ESR?, EVENT?, *SRE, *STB
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3–21
Commands
Examples
Might return the message:
.
EVQTy? (Query Only)
The EVQTy? query returns returns the number of events associated with the last
Standard Event Status Register read and thus the length of a subsequent response
to an ALLev? query. The maximum number of event queue items is 32.
Related Commands
Syntax
*CLS, DESE, *ESE, *ESR?, EVMSG?, *SRE, *STB
Examples
Might return the response , showing that there are four events in
the event queue.
FACTory (No Query Form)
The FACTory command resets the VXOA41 to its factory default settings and
purges stored settings.
NOTE. The FACTory command can take 5 to 10 seconds to complete depending
on attenuation settings.
Related Commands
Syntax
DESE, *ESE, HEADER, *PSC, *RST, *SRE, VERBOSE
3–22
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Commands
The FACTory command does the following:
Puts the VXOA41 in the Operation Complete Command Idle State.
Puts the VXOA41 in the Operation Complete Query Idle State.
Clears the Event Status Enable Register (equivalent to the command
).
Clears the Service Request Enable Register (equivalent to the command
).
Sets the Device Event Status Enable Register to all-enabled (equivalent to
the command ).
Sets the Power-on status clear flag to TRUE (equivalent to the command
).
Sets the Response Header Enable State to TRUE (equivalent to the
command ).
Sets the Verbose Header State to TRUE (equivalent to the command
).
Sets the certain parameters as shown in Table 3–8.
Table 3–8: FACTory Default Settings
Parameter
Setting
The FACTory command does not alter the following items:
The state of the VXI interface.
The selected VXI address.
Calibration data that affects device specifications.
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3–23
Commands
HEADer
The HEADer command sets and queries the Response Header Enable State that
causes the VXOA41 to either include or omit headers on query responses. This
command does not affect IEEE Std 488.2 Common Commands (those starting
with an asterisk) or the *LRN? response.
Related Commands
Syntax
VERBOSE
HEADer { ON | OFF | <NRf> }
HEADer?
ON
<Space>
OFF
<NRf>
HEADer
?
Arguments
ON or <NRf> 0 sets the Response Header Enable State to TRUE. This causes
the VXOA41 to include headers on applicable query responses. You can then use
the query response as a command.
OFF or <NRf> = 0 sets the Response Header Enable State to FALSE. This causes
the VXOA41 to omit headers on query responses, so that only the argument is
returned.
Examples
HEADER OFF
Causes the VXOA41 to omit headers from query responses.
HEADER 1
Causes the VXOA41 to include headers on applicable query responses.
HEADER?
Might return the value 1, showing that the Response Header Enable State is
TRUE.
*IDN? (Query Only)
The *IDN? (Identification) query returns the VXOA41’s unique identification
code.
3–24
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Commands
Syntax
*IDN?
*IDN
?
The query response is an ASCII string separated into four fields by commas:
TEKTRONIX,VXOA41,<serial number>,CF:91.1CN RM:<firmware version
number>
Examples
*IDN?
Might return the response:
TEKTRONIX,VXOA41,B010101,CF:91.1CN RM:1.5
*LRN? or SET?
The *LRN? (Learn Device Setup) or SET? query returns a string listing the
VXOA41’s settings, except for calibration values. You can use this string to
return the VXOA41 to the state it was in when you made the *LRN? query.
Related Commands
Syntax
HEADER, VERBOSE
*LRN?
SET?
*LRN
?
SET
NOTE. The *LRN? query always returns a string with command headers,
regardless of the setting of the HEADER command. This is because the returned
string is intended to be able to be sent back to the VXOA41 as a command
string. The VERBOSE command can still be used to specify whether the returned
headers should be abbreviated or full length.
Examples
*LRN?
Might return the string:
:REFERENCE 0.00;:WAVELENGTH 1300;:ATTENUATION:DB 0.00;:DISĆ
PLAY DB;:DISABLE 0;:STORE1 0.00;:STORE2 0.00
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3–25
Commands
*OPC
The *OPC (Operation Complete) command generates the operation complete
message in the Standard Event Status Register (SESR) when all pending
operations finish. The *OPC? query places the ASCII character “1” into the
Output Queue when all pending operations are finished. The *OPC? response is
not available to read until all pending operations finish. For a complete
discussion of the use of these registers and the output queue, see page 3–35.
Related Commands
Syntax
*WAI, ADJusting?
*OPT? (Query Only)
The *OPT (Option Identification Query) command returns a string that identifies
what options are installed in the VXOA41.
Related Commands
Syntax
N/A
Returns
Examples
3–26
The command returns a single “” if the VXOA41 is in standard configuration
(no options, single-mode fiber). If options are installed, the command returns a
string of three fields, with each field separated by a comma. Each of the fields
represents one of the possible options. Since the options are mutually exclusive,
two of the fields will always be “0”. One of the fields, which one depends on
what option is installed, will indicate the installed option with the syntax:
“ ! " " # ”
Might return the string:
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Commands
*PSC
The *PSC (Power-On Status Clear) command sets and queries the power-on
status flag that controls the automatic power-on handling of the DESER, SRER,
and ESER registers. When PSC is TRUE, the DESER register is set to 255 and
the SRER and ESER registers are set to 0 at power-on. When PSC is FALSE, the
current values in the DESER, SRER, and ESER registers are preserved in
non-volatile memory when power is shut off and restored at power-on. For a
complete discussion of the use of these registers, see page 3–35.
Related Commands
Syntax
DESE, *ESE, *RST, *SRE
Arguments
is a value in the range from –32767 to 32767.
= 0 sets the power-on status clear flag to FALSE, disables the power-on
clear and allows the VXOA41 to assert SRQ after power-on.
0 sets the power-on status clear flag TRUE. Sending *PSC 1 therefore
enables the power-on clear and prevents any SRQ assertion after power-on.
Using an out-of-range value causes an execution error.
Examples
Sets the power-on status clear flag to FALSE.
Might return the value , showing that the power-on status clear flag is set to
TRUE.
RECall (No Query Form)
The RECall command sets the attenuation of the instrument to either stored
value 1 or 2.
Related Commands
STORe
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3–27
Commands
Syntax
REFerence
This command reads and sets the reference used when returning the attenuation
in the ATT–REF mode. The units for command mode and responses is dB.
Values smaller than 0.01 dB are rounded to the nearest one-hundredth dB. The
REF value may not exceed ±99.99. The combination of the REF value and the
ATTen value may not exceed ±99.99. For example, if the ATTen value is set to
30 dB and the REF value is set to –70 dB, the resultant ATT–REF value would
be 100 dB, and an execution error event would result. The factory default for
REF is 0.00 (dB).
Related Commands
Syntax
N/A
Arguments
Examples
is a number that cannot exceed ±99.99.
Sets the REFerence value to 45.00 dB.
Would return the string:
:REF 45.00
*RST (No Query Form)
The *RST (Reset) command returns the VXOA41 to a known set of instrument
settings.
3–28
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Commands
NOTE. The *RST command can take 5 to 10 seconds to complete depending on
attenuation settings.
Related Commands
Syntax
*PSC, FACTory
*RST does the following:
Puts the VXOA41 into the Operation Complete Command Idle State.
Puts the VXOA41 into the Operation Complete Query Idle State.
Returns the instrument settings to those listed on page 3–23.
The *RST command does not alter the following:
The state of the IEEE Std 488.2 interface.
The selected IEEE Std 488.2 address of the VXOA41.
Calibration data that affects device specifications.
The Output Queue.
The Standard Status Register Enable setting.
The Standard Event Status Enable setting.
The Power-on status clear flag setting.
HEADer and VERBose settings.
*SRE
The *SRE (Service Request Enable) command sets and queries the bits in the
Service Request Enable Register (SRER). For a complete discussion of the use
of these registers, see page 3–35.
Related Commands
ALLev?, *CLS, DESE, *ESE, *ESR, EVENT?, EVMSG?, EVQty?, *PSC,
*STB
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3–29
Commands
Returns
*SRE <NRf>
*SRE?
<Space>
<NRf>
*SRE
?
Arguments
<NRf> is a value in the range from 0 to 255. The binary bits of the SRER are set
according to this value. Using an out-of-range value causes an execution error.
The power-on default for SRER is 0 if *PSC is 1. If *PSC is 0, the SRER
maintains its value through a power cycle.
Examples
*SRE 48
Sets the bits in the SRER to 00110000 binary.
*SRE?
Might return a value of 32, showing that the bits in the SRER have the
binary value 00100000.
*STB? (Query Only)
The *STB? (Read Status Byte) query returns the Status Byte Register (SBR)
using the Master Summary Status (MSS) bit. For a complete discussion of the
use of these registers, see page 3–35.
Related Commands
Syntax
ALLev?, *CLS, DESE, *ESE, *ESR, EVENT?, EVMSG?, EVQty?, *SRE
*STB?
*STB
Examples
3–30
?
*STB?
Might return the value 96, showing that the STB contains the binary value
01100000.
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Commands
STORe
The STORe command, Store Attenuation, sets or reads the value of stored
positions 1 or 2. Using the command form (for example, STOR1) without a
value specified stores the current attenuation in the specified location.
Related Commands
Syntax
RECall
STORe { 1 | 2 }?
STORe { 1 | 2 }
STORe { 1 | 2 } <NRf>
?
1
STORe
<Space>
2
Arguments
Examples
<Space>
<NRf>
<NRf> specifies the attenuation value to be stored. The range for the attenuation
value is 0 <NRf> 60.00. All attenuation values associated with the STORe
command and query forms are in absolute dB and never include the REFERENCE value, even if the front panel display shows that the VXOA41 is set to
ATT-REF mode.
STORE1?
Returns the attenuation value stored in register 1, in the form:
:STORE1 <NRf>
STORE1 20.00
Sets the attenuation value in stored register 1 to 20.00 dB.
STORE2
Stores the current attenuation value in stored register 2.
*TST? (Query Only)
The *TST? (Self-Test) query runs the VXOA41 internal self-test and reports the
results. The self-test does not require operator interaction and does not create bus
conditions that violate IEEE Std 488.1/488.2 standards. When complete, the
VXOA41 returns to the state it was in just prior to the self-test. The test response
is a value <NR1> as described in Table 3–9.
Related Commands
N/A
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3–31
Commands
NOTE. If an error is detected, *TST? stops and returns an error code and does
not complete any remaining tests. It also places a device dependent event in the
event queue.
Syntax
NOTE. The *TST? query can take 5 seconds or more to respond.
Table 3–9: Results from *TST?
Examples
<NR1>
Meaning
0
Test completed with no errors detected
101, 102
ROM checksum error
104
Non-volatile RAM is bad
115
System timer is bad
401
Calibration EEPROM is bad
410, 411
Calibration needed
Might return the value , indicating that the system timer is not working
correctly.
VERBOSE
The VERBOSE command sets and queries the Verbose Header State that
controls the length of headers on query responses. This command does not affect
IEEE Std 488.2 Common Commands (those starting with an asterisk).
Related Commands
3–32
HEADER, *LRN?
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Commands
Syntax
VERBOSE { ON | OFF | <NRf> }
VERBOSE?
ON
<Space>
OFF
<NRf>
VERBOSE
?
Arguments
ON or <NRf> 0 sets the Verbose Header State TRUE, which returns full-length
headers for applicable setting queries.
OFF or <NRf> = 0 sets the Verbose Header State FALSE, which returns minimum-
length headers for applicable setting queries.
Examples
VERBOSE ON
Sets the Verbose Header State TRUE.
VERBOSE?
Might return the value 1, showing that the Verbose Header State is TRUE.
*WAI (No Query Form)
The *WAI (Wait) command prevents the VXOA41 from executing further
commands or queries until all pending operations finish.
Related Commands
Syntax
*OPC, ADJusting?
*WAI
*WAI
WAVelength
This commands set or queries the wavelength used by the instrument when
determining the equivalent attenuator positioning for a given attenuation.
Related Commands
N/A
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3–33
Commands
Syntax
" "
!
"
Arguments
Examples
The valid range for the wavelength argument is 600 nm to 1700 nm. Default
units are always in nanometers with N (for nano or 1E–09) and U (for micro or
1E–06) accepted as multipliers; M (for meters) is also an acceptable term (see
examples below).
Returns the value of wavelength to which the VXOA41 is set. An example
response is:
Sets the wavelength to 1300 nm.
Sets the wavelength to 1300 nm.
Sets the wavelength to 1300 nm.
Sets the wavelength to 1300 nm.
3–34
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Status and Events
The VXOA41 provides a status and event reporting system for the programming
interface. This system informs you of certain significant events that occur within
the VXOA41.
The VXOA41 status handling system consists of five 8-bit registers and two
queues. This section describes these registers and components and explains how
the event handling system operates.
Registers
The registers in the event handling system fall into two functional groups:
Status Registers
The Standard Event Status Register (SESR) and the Status Byte Register
(SBR) contain information about the status of the VXOA41. These registers
are therefore called the Status Registers.
The Device Event Status Enable Register (DESER), the Event Status Enable
Register (ESER), and the Service Request Enable Register (SRER)
determine whether selected types of events are reported to the Status
Registers and the Event Queue. These three registers are called the Enable
Registers.
The Standard Event Status Register (SESR) and the Status Byte Register (SBR)
record certain types of events that may occur while the VXOA41 is in use. These
registers are defined by IEEE Std 488.2. Refer also to Figure 3-4 and Table
3–10.
Each bit in a Status Register records a particular type of event, such as an
execution error or service request. When an event of a given type occurs, the bit
that represents that type of event is set to a value of one. (You can disable bits so
that they ignore events and remain at zero; see the Enable Registers section on
page 3–37.) Reading the status registers tells you what types of events have
occurred.
The Standard Event Status Register (SESR). The SESR, shown in Figure 3-4,
records eight types of events that can occur within the VXOA41. Use the *ESR?
query to read the SESR register. Reading the register clears the bits of the
register so that the register can accumulate information about new events.
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3–35
Status and Events
7
6
5
PON
URQ
CME
4
EXE
3
2
1
0
DDE
QYE
RQC
OPC
Figure 3-4: The Standard Event Status Register (SESR)
Table 3–10: SESR Bit Functions
Bit
Function
7 (MSB)
PON (Power On). Shows that the VXOA41 was powered on.
6
URQ (User Request). Not used.
5
CME (Command Error). Shows that an error occurred while the VXOA41
was parsing a command or query. Table 3–13, on page 3–41, lists
Command error messages.
4
EXE (Execution Error). Shows that an error occurred while the VXOA41 was
executing a command or query. Table 3–14, on page 3–42, lists Execution
error messages.
3
DDE (Device Error). Shows that a device error occurred. Table 3–15, on
page 3–43, lists Device error messages.
2
QYE (Query Error). Shows that either an attempt was made to read the
Output Queue when no data was present or pending, or that data in the
Output Queue was lost.
1
RQC (Request Control). Not used.
0 (LSB)
OPC (Operation Complete). Shows that the operation is complete. The
*OPC command sets this bit.
The Status Byte Register (SBR). The SBR, shown in Figure 3-5, records whether
output is available in the Output Queue, whether the VXOA41 requests service,
and whether the SESR has recorded any events.
Use a “Read STB“ word serial command or the *STB? query to read the
contents of the SBR. Refer to Table 3–11. The bits in the SBR are set and cleared
depending on the contents of the SESR, the Event Status Enable Register
(ESER), and the Output Queue. (When you use the Read STB word serial
command to obtain the SBR, bit 6 is the RQS bit. When you use the *STB?
query to obtain the SBR, bit 6 is the MSS bit.)
6
RQS
7
—
6
5
ESB
4
MAV
3
2
—
1
—
0
—
—
MSS
Figure 3-5: The Status Byte Register (SBR)
3–36
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Status and Events
Table 3–11: SBR Bit Functions
Bit
Function
7 (MSB)
Not used (always 0).
6*
RQS (Request Service ), obtained from a “Read STB” word serial command.
Shows that the VXOA41 requests service from the controller.
6
MSS (Master Status Summary), obtained from *STB? query. Summarizes
the ESB and MAV bits in the SBR.
5
ESB (Event Status Bit). Shows that status is enabled and present in the
SESR.
4
MAV (Message Available). Shows that output is available in the Output
Queue.
3–0
Not used (always 0).
*
Enable Registers
When the user has enabled a VME interrupt for the VXOA41, this bit is the indicator
of whether the VME interrupt has been asserted.
The DESER, ESER, and SRER allow you to select which events are reported to
the Status Registers and the Event Queue. Each Enable Register acts as a filter to
a Status Register (the DESER also acts as a filter to the Event Queue) and can
prevent information from being recorded in the register or queue.
Each bit in an Enable Register corresponds to a bit in the Status Register it
controls. In order for an event to be reported to its bit in the Status Register, the
corresponding bit in the Enable Register must be set to 1. If the bit in the Enable
Register is set to 0, the event is not recorded.
The next section describes the Enable Registers and the commands used to set
them.
The Device Event Status Enable Register (DESER). Figure 3-6 shows the DESER.
This DESER controls which types of events are reported to the SESR and the
Event Queue. The bits in the DESER correspond to those in the SESR, as
described earlier.
Use the DESE command to enable and disable the bits in the DESER. Use the
DESE? query to read the DESER.
7
6
5
PON
URQ
CME
4
EXE
3
2
1
0
DDE
QYE
RQC
OPC
Figure 3-6: The Device Event Status Enable Register (DESER)
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3–37
Status and Events
The Event Status Enable Register (ESER). Figure 3-7 shows the ESER. The ESER
controls which types of events are summarized by the Event Status Bit (ESB) in
the SBR.
Use the *ESE command to set the bits in the ESER, and use the *ESE? query to
read it.
7
6
5
PON
URQ
CME
4
EXE
3
2
1
0
DDE
QYE
RQC
OPC
Figure 3-7: The Event Status Enable Register (ESER)
The Service Request Enable Register (SRER). Figure 3-8 shows the SRER. The
SRER controls which bits in the SBR generate a Service Request and are
summarized by the Master Status Summary (MSS) bit.
Use the *SRE command to set the SRER. Use the SRE? query to read it. The
RQS bit remains set to one until either the Status Byte Register is read with a
Read STB word serial command or the MSS bit changes back to a zero.
7
6
—
5
—
ESB
4
MAV
3
2
—
1
—
0
—
—
Figure 3-8: The Service Request Enable Register (SRER)
The Enable Registers and
the *PSC Command
The *PSC command controls the contents of the Enable Registers at power-on.
Sending *PSC 1 sets the Enable Registers at power on as follows:
DESER 255 (equivalent to a DESe 255 command)
ESER 0 (equivalent to an *ESE 0 command)
SRER 0 (equivalent to an *SRE command)
Sending *PSC 0 lets the Enable Registers maintain their values in nonvolatile
memory through a power cycle.
NOTE. To enable the PON (Power On) event to generate a Service Request, send
*PSC 0, use the DESe and *ESE commands to enable PON in the DESER and
ESER, and use the *SRE command to enable bit 5 in the SRER. Subsequent
power-on cycles will generate a Service Request.
3–38
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Status and Events
Queues
The VXOA41 status and event reporting system contains two queues: the Output
Queue and the Event Queue.
The Output Queue
The Output Queue stores up to 8000 bytes of a query response while it is waiting
to be output. The Output Queue is emptied each time a new command or query
message is received. Because of this, all query responses must be read before the
next command or query is sent, otherwise responses to earlier queries will be lost
and an error may result.
The Event Queue
The Event Queue stores detailed information on up to 32 events. If more than 32
events fill the Event Queue, the thirty-second event is replaced by event code
350, “Too many events.”
To read the Event Queue, use either the EVENT? query (which returns only the
event number) or the EVMSG? query (which returns the event number and a text
description of the event). Reading an event removes it from the queue.
Before reading an event from the Event Queue, you must use the *ESR? query to
read the summary of that event from the SESR. Sending an *ESR? query makes
the events summarized by the *ESR? read available to the EVENT? and
EVMSG? queries, and empties the SESR.
Reading the SESR erases any events that were summarized by a previous *ESR?
read but not read from the Event Queue. Events that follow an *ESR? read are
put in the Event Queue but are not available until *ESR? is used again.
Event Handling Sequence
Figure 3-9, on page 3–40, shows how to use the status and event handling
system. In the explanation that follows, numbers in parentheses refer to numbers
in Figure 3-9.
When an event occurs, a signal is sent to the DESER (1). If that type of event is
enabled in the DESER (that is, if the bit for that event type is set to 1), the
appropriate bit in the SESR is set to one and the event is recorded in the Event
Queue (2). If the corresponding bit in the ESER is also enabled (3), then the ESB
bit in the SBR is set to one (4).
When output is sent to the Output Queue, the MAV bit in the SBR is set to
one (5).
When a bit in the SBR is set to one and the corresponding bit in the SRER is
enabled (6), the MSS bit in the SBR is set to one and a service request is
generated (7).
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3–39
Status and Events
1
Device Event Status Enable Register
(DESER)
7
6
5
PON
URQ
CME
4
EXE
3
2
1
0
DDE
QYE
RQC
OPC
3
2
1
0
DDE
QYE
RQC
OPC
2
Standard Event Status Register (SESR)
7
6
5
PON
URQ
CME
4
EXE
7
6
5
PON
URQ
CME
4
EXE
Event
Queue
Event
3
Event Status Enable Register
(ESER)
Event
Event
3
2
1
0
DDE
QYE
RQC
OPC
Byte
Byte
Output
Queue
Byte
4
5
6
RQS
7
Status Byte Register
(SBR)
—
5
ESB
6
4
3
MAV
2
—
1
—
0
—
—
MSS
6
7
Service Request Enable Register
(SRER)
7
6
—
5
—
ESB
4
MAV
3
2
—
1
—
0
—
—
Figure 3-9: Status and Event Handling Process
Conflicts
Whenever a command is issued that results in a conflict, an event is generated on
the EXE bit (bit 4).
To avoid generating this event, concatenate commands so that the conflict is
resolved when the command is completed. For example, when setting the
attenuator in DBR mode, always make sure that the REF command precedes the
ATT:DBR command,otherwise an execution warning will result.
3–40
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Status and Events
Messages
Tables 3–12 through 3–17 list all the programming interface messages the
VXOA41 generates in response to commands and queries.
For most messages, a secondary message from the VXOA41 gives more detail
about the cause of the error or the meaning of the message. This message is part
of the message string and is separated from the main message by a semicolon.
Each message is the result of an event. Each type of event sets a specific bit in
the SESR and is controlled by the equivalent bit in the DESER. Thus, each
message is associated with a specific SESR bit. In the message tables that follow,
the associated SESR bit is specified in the table title, with exceptions noted with
the error message text.
Table 3–12 lists the messages returned when the system has no events or status
to report. These have no associated SESR bit.
Table 3–12: No Event Messages
Code
Message
0
No events to report – queue empty
1
No events to report – new events pending *ESR?
Table 3–13 lists the error messages generated by improper command syntax.
Check that the command is properly formed and that it follows the rules in the
Command Syntax chapter starting on page 3–1.
Table 3–13: Command Error Messages — CME Bit 5
Code
Message
100
Command error
101
Invalid character
102
Syntax error
103
Invalid message or unit separator
104
Data type error
105
GET not allowed
106
Invalid program data separator
108
Parameter not allowed
109
Missing parameter
110
Command header error
111
Header separator error
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3–41
Status and Events
Table 3–13: Command Error Messages — CME Bit 5 (Cont.)
Code
Message
112
Program mnemonic too long
113
Undefined header
118
Query not allowed
120
Numeric data error
121
Invalid character in number
123
Numeric overflow
124
Too many digits
128
Numeric data not allowed
130
Suffix error
131
Invalid suffix
134
Suffix too long
138
Suffix not allowed
140
Character data error
141
Invalid character data
144
Character data too long
148
Character data not allowed
150
String data error
151
Invalid string data
158
String data not allowed
160
Block data error
161
Invalid block data
168
Block data not allowed
Table 3–14 lists the execution errors that are detected during execution of a
command.
Table 3–14: Execution Error Messages — EXE Bit 4
3–42
Code
Message
200
Execution error
220
Parameter Error
221
Settings in conflict
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Status and Events
Table 3–14: Execution Error Messages — EXE Bit 4 (Cont.)
Code
Message
222
Data out of range
223
Too much data
Table 3–15 lists the device errors that can occur during operation of the
VXOA41. These errors may indicate that the VXOA41 needs repair.
Table 3–15: Device Error Messages — DDE Bit 3
Code
Message
300
Internal error
310
System error
313
Calibration memory lost
315
Configuration memory lost
350
Too many events (does not set DDE bit)
Table 3–16 lists the system event messages. These messages are generated
whenever certain system conditions occur.
Table 3–16: System Event Messages — QYE Bit 2
Code
Message
401
Power on – PON Bit 7
402
Operation complete – OPC Bit 0
403
User request – URQ Bit 6
410
Query interrupted
420
Query unterminated
430
Query deadlocked
440
Query unterminated after indefinite response
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3–43
Status and Events
Table 3–17 lists warning messages that do not interrupt the flow of command
execution. These notify you that you might get unexpected results.
Table 3–17: Execution Warning Messages — EXE Bit 4
3–44
Code
Message
500
Execution warning
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Appendices
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Appendix A: Accessories and Options
The following paragraphs describe the standard and optional accessories for the
VXOA41 Optical Attenuator. To purchase optional accessories, or purchase
additional standard accessories, see a Tektronix products catalog or contact your
local Tektronix field representative.
Standard Accessories
The VXOA41 Optical Attenuator User Manual (Tektronix part number
070-8777-00) is this manual.
Optional Accessories
The optional accessories appropriate for your instrument depend on which option
was installed on your VXOA41 at the time of purchase.
Optical Cables, Single Mode, 2 meter, 8/125 micron
FC/PC to Diamond 2.5, Tektronix part number 174-1497-00.
FC/PC to Diamond 3.5, Tektronix part number 174-1385-00.
FC/PC to ST, Tektronix part number 174-1386-00.
FC/PC to FC/PC, Tektronix part number 174-1387-00.
FC/PC to Biconic, Tektronix part number 174-1388-00.
Optical Cables, Multimode, 2 meter, 62.5/140 micron
FC/PC to Biconic, Tektronix part number 174-2323-00.
FC/PC to SMA906, Tektronix part number 174-2324-00.
FC/PC to FC/PC, Tektronix part number 174-2322-00.
Optical Cables, Multimode, 2 meter, 100/140 micron
NOTE. At the time of publication, the 100 m cables listed below do not utilize
physical contact connectors.
FC to SMA, Tektronix part number 174-0878-00.
ST to SMA, Tektronix part number 174-0876-00.
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A–1
Appendix A: Accessories and Options
Diamond 2.5 to SMA, Tektronix part number 174-1303-00.
Optical Connector Kit
Universal optical input and output connector kit, Tektronix part number
020-1885-00.
NOTE. Each connector kit contains only one connector. To change both optical
connectors on the VXOA41 you must purchase two kits.
Options
The following options are available for the VXOA41.
Option 1: 50 Micron
Multimode Fiber
A–2
Option 1 changes the optical input and output ports to accept 50 mm multimode
fiber, utilizing FC-PC connections.
Option 2: 62.5 Micron
Multimode Fiber
Option 2 changes the optical input and output ports to accept 62.5 mm multimode
fiber, utilizing FC-PC connections.
Option 3: 100 Micron
Multimode Fiber
Option 3 changes the optical input and output ports to accept 100 mm multimode
fiber, utilizing FC-PC connections.
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Appendix B: Specifications
The performance characteristics described in this appendix (Tables B–1 through
B–3) are valid under the following conditions:
H
The instrument must have been calibrated at an ambient temperature between
+20_ C and +30_ C.
H
The instrument must have had a warm-up period of at least 20 minutes.
H
All optical connections to the instrument are made using physical contact
connectors. Tektronix offers a limited selection of fiber optic jumper cables
which utilize physical contact on the connector ends (for example, Tektronix
part number 174-1387-00; see Appendix A).
H
Both input and output connectors have been cleaned as described on page
F–1.
Table B–1: Optical Characteristics
Characteristics
Specification
Wavelength Range
600 nm – 1700 nm
Input
Standard
Singlemode Fiber
Option 1
50 m Multimode Fiber
Option 2
62.5 m Multimode Fiber
Option 3
100 m Multimode Fiber
Insertion Loss
1100 – 1700 nm
≤ 2.0 dB
700 – 1100 nm
≤ 4.0 dB
Return Loss
≤ 45 dB
Option 1
≤ 25 dB
Option 2
≤ 25 dB
Option 3
≤ 25 dB
Attenuation Range
600 – 1350 nm
≥ 60 dB (calibrated, 0.01 dB step size)
1350 – 1600 nm
≥ 50 dB (calibrated, 0.01 dB step size)
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B–1
Appendix B: Specifications
Table B–1: Optical Characteristics (Cont.)
Characteristics
Specification
Maximum Attenuation
≥ 100 dB (shutter activated)
Option 1
≥ 100 dB (shutter activated)
Option 2
≥ 100 dB (shutter activated)
Option 3
≥ 90 dB (shutter activated)
Repeatability
± 0.05 dB
Linearity
± 0.05 dB
Accuracy
850 ± 20 nm
≤ 0.15 dB (typically ≤ 0.05 dB)
1300 ± 20 nm
≤ 0.15 dB (typically ≤ 0.05 dB)
1500 ± 20 nm
≤ 0.15 dB (typically ≤ 0.05 dB)
Table B–2: Physical Characteristics
Characteristics
Specification
Net Weight
2.4 kg (5.25 lb)
External Dimensions
Height
60.66 mm (2.39 in)
Width
366.70 mm (14.38 in)
Length
345.03 mm (13.58 in)
Table B–3: Environmental Performance
Characteristic
Specification
Temperature
Operating
0° C to +50° C (32° F to 122° F)
Nonoperating
(storage)
–40° C to +70° C (–40° F to 160° F)
(Meets MIL-T-28800D, class 5)
Humidity
Operating and
Nonoperating
B–2
95% RH: 11_ C to 30_C (52_ F to 86_ F)
75% RH: 11_ C to 40_C (52_ F to 104_ F)
45% RH: 11_ C to 50_C (52_ F to 122_ F)
(Exceeds MIL-T-28800D, Class 5, noncondensing)
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Appendix B: Specifications
Table B–3: Environmental Performance (Cont.)
Characteristic
Specification
Vibration
0.38 mm (0.015 in) p-p, 5 Hz to 55 Hz, 75 minutes. Meets
MIL-T-28800D, Class 5, when installed in qualified power
modules.
Shock
30 g’s, (1/2 sine), 11 ms duration, 3 shocks in each direction
along 3 major axes, 18 total shocks. Meets MIL-T-28800D,
Class 5, when installed in qualified power modules.
Bench Handling
12 drops from 45°, 4 in or equilibrium, whichever occurs first.
Meets MIL-T-28800D, Class 5, when installed in qualified
power modules, and IEC 348 (Electronic measuring
apparatus).
Packaged Product Vibration and
Shock
The packaged product qualifies under the National Safe
Transit Association’s Preshipment Test Procedures, Project
1A-B-1 and 1A-B-2.
Table B–4: Certifications and compliances
Characteristic
Specification
EC Declaration of Conformity –
EMC
Meets intent of Directive 89/336/EEC for Electromagnetic
Compatibility. Compliance was demonstrated to the following
specifications as listed in the Official Journal of the European
Communities:
EN 50081-1 Emissions:
EN 55011 Class A Radiated and Conducted Emissions
EN 60555-2 AC Power Line Harmonic Emissions
EN 50082-1 Immunity:
IEC 801-2
IEC 801-3
IEC 801-4
IEC 801-5
FCC Compliance
Electrostatic Discharge Immunity
RF Electromagnetic Field Immunity
Electrical Fast Transient/Burst Immunity
Power Line Surge Immunity
Emissions comply with FCC Code of Federal Regulations
47, Part 15, Subpart B, Class A Limits
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B–3
Appendix B: Specifications
B–4
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Appendix C: Interface Specifications
Interface Standard
The VXOA41 conforms to the VXIbus Specification Version 1.3 as a messagebased I4 device. All instrument commands comply with the IEEE 488.2
standard.
No commander capability
No Signal Register
No VMEbus master capability
No Fast Handshake
No Shared Memory
No Response Generator
Can generate events
Has programmable interrupter
No interrupt handling
Has Trigger word serial command
Supports VXIbus 488.2 protocol
Supports VXIbus instrument protocol
No extended long word protocol
No longword protocol
The VXOA41 manufacturer identification number is 4093. The VXOA41 device
identification number is 4080. Both of these numbers are printed on the label
located on the right-side shield of the VXOA41.
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C–1
Appendix C: Interface Specifications
Character Set (ASCII Chart)
Table C–1 shows the character set used for all messages to and from the
VXOA41. This is identical to standard ASCII.
Table C–1: The ASCII Character Set
!
"
#
$
%
&
C–2
.5,
3/(
348
%48
%/4
%.1
!#+
"%,
"3
(4
,&
64
&&
#2
3/
3)
$,%
$#
$#
$#
$#
.!+
39.
%4"
#!.
%35"
%3#
&3
'3
23
53
SPACE
!
"
#
$
%
&
'
(
)
*
+
,
.
/
0
1
2
3
4
5
6
7
8
9
:
;
<
=
>
?
@
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
[
\
]
^
RUBOUT
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Appendix C: Interface Specifications
VXI Word Serial Commands
The VXOA41 recognizes the following VXI word serial commands. These
commands are described in the VXIbus Specification Version 1.3. Each word
serial command is a 16-bit word that the Slot 0 controller sends to the instrument
via its data low register.
Abort Normal Operation
Halts any pending or active operations from the bus and goes into the CONFIGURE substate of the PASSED state. While in the CONFIGURE substate, the
DIR bit in the response register is 0 and the instrument cannot accept commands
via the Byte Available or Byte Request word serial commands. A Begin Normal
Operation command is required to put the instrument into the NORMAL
OPERATION substate.
Assign Interrupter Line
Assigns a VME interrupt line for use. This interrupt line is used the same way as
the SRQ line is used in a GPIB system. The instrument can be configured to
generate an interrupt on the assigned interrupt line when an event is activated.
Asynchronous Mode
Control
Enables the generation of events by the instrument. The only valid setting of this
command is to enable/disable events that can generate an interrupt. Signals and
responses are not supported.
Begin Normal Operation
Byte Available
Byte Request
Clear
Clear Lock
Sent by the resource manager of the system to take the instrument out of the
CONFIGURE substate and into the NORMAL OPERATION substate. After
receipt of this command, the instrument asserts the DIR bit of its response
register and is ready to accept commands via the Byte Available word serial
command.
Indicates that the commander has put a byte of data into the data register. This
command is equivalent to a GPIB controller addressing an instrument to listen
and then sending a byte of data to it.
The commander is ready to receive a byte of data from the instrument as a result
of a previous query.
Causes the instrument to clear the VXIbus of any pending operations. This is
analogous to sending DCL or SDC on the GPIB.
Causes the instrument to exit the locked state (sets the Locked* bit of the
response register). The equivalent GPIB command is RTL.
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C–3
Appendix C: Interface Specifications
Control Event
End Normal Operation
Read Interrupter Line
When the instrument finishes any pending operations, it enters the CONFIGURE
substate. While in the CONFIGURE substate, the DIR bit in the response
register is 0 and the instrument cannot accept commands via the Byte Available
or Byte Request word serial commands. A Begin Normal Operation command is
required to put the instrument into the NORMAL OPERATION substate.
Returns the currently assigned VME interrupter line.
Read Interrupters
Returns the number of interrupters supported. The VXOA41 supports only one
interrupter.
Read Protocol
Returns the capabilities of the instrument to the Commander. This word always
has the value 0xFE23.
Read Protocol Error
Read STB
Set Lock
Trigger
C–4
Enables the generation of events by the instrument. The two event types
supported are request true and request false.
Reports the most recent word serial protocol error code to the commander.
Returns the value of the status byte. This command is analogous to a serial poll
on the GPIB (refer to the section Status and Events).
Puts the instrument into the locked state (the Locked* bit of the response register
is cleared).
This command causes the attenuator to change its attenuation setting by the
current increment amount, if the increment is nonzero. See ATTenuate:INCRement and ATTenuate:NEXT in the Commands section.
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Appendix D: Using the *OPC Query/Command
When you are using the VXOA41 in an automated test environment, it is
important that you be aware of the finite times for certain commands to
complete. For example, suppose you develop an automated test in which the
attenuator is adjusted over the VXI bus via the ATT:DB n command. After each
adjustment by the attenuator, you might then take a reading from an optical
power meter (such as the Tektronix OCP 5502). In such a sequence, it is
important that you not initiate the reading from the optical power meter before
the VXOA41 has completed all adjustments and has come to a stable position
(that is, the ATT ADJ indicator is no longer illuminated).
Below is an example that illustrates the use of instrument commands and queries
utilizing the *OPC? query/command. In this example, queries to other instruments (such as the power meter) are not made until all of the VXOA41’s pending
operations have completed.
Example: A command is sent to the VXOA41 to change attenuation to 45 dB;
the command is immediately followed by an *OPC? query to the same
VXOA41.
1. Write to the VXOA41 VXI address: ATT:DB 45.00; *OPC?
2. Read from VXOA41 the VXI address: 1
Depending on the previous attenuation setting of the VXOA41, several seconds
may be required before the ATT:DB command is completed and the *OPC?
produces a “1” in the VXOA41 output queue. After the *OPC? query is sent to
the VXOA41, the programmer should immediately attempt a read instruction
from the controller. The programmer’s controller should wait until the VXOA41
finishes all adjustments and the *OPC query provides a “1” to be read.
NOTE. It is important that you remember to set the time-out of the controller’s
READ instruction to be greater than the longest time possible for the VXOA41 to
make any adjustments (up to five seconds may be required to make large changes
to attenuation settings).
You can also have the OPC bit of the SESR set by using the command form of
*OPC instead of the query form. By setting the OPC bit to “1” via an *OPC
command, an event will be generated assuming the user has enabled the proper
register bits.
Advanced programmers can develop other methods to accomplish the
set-and-wait-until-complete routine utilizing the event queues and status
registers provided in the VXOA41.
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D–1
Appendix D: Using the *OPC Query/Command
D–2
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Appendix E: Packing for Shipment
If you ship the VXOA41, pack it in the original shipping carton and packing
material. If the original packing material is not available, package the instrument
as follows:
1. Obtain a corrugated cardboard shipping carton with inside dimensions at
least 15 cm (6 in) taller, wider, and deeper than the VXOA41. The shipping
carton must be constructed of cardboard with 375 pound test strength.
2. If you are shipping the VXOA41 to a Tektronix field office for repair, attach
a tag to the VXOA41 showing the instrument owner and address, the name
of the person to contact about the instrument, the instrument type, and the
serial number.
3. Wrap the VXOA41 with polyethelene sheeting or equivalent material to
protect the finish.
4. Cushion the VXOA41 in the shipping carton by tightly packing dunnage or
urethane foam on all sides between the carton and the VXOA41. Allow
7.5 cm (3 in) on all sides, top, and bottom.
5. Seal the shipping carton with shipping tape or an industrial stapler.
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E–1
Appendix E: Packing for Shipment
E–2
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Appendix F: Maintenance
This appendix describes how to perform routine maintenance on the VXOA41
Optical Attenuator. There are no user-serviceable parts in the VXOA41. Should
your instrument need service, contact your nearest Tektronix service representative.
The following maintenance procedures are discussed in this chapter.
Cleaning the Optical Ports
Changing the Optical Port Connectors
Cleaning the Optical Ports
If the VXOA41 performance appears degraded, the optical fiber and optical port
may be dirty. Clean the fiber connector with a clean cloth. To clean an optical
port, perform the following steps:
1. Turn the power supply off and then pull the VXOA41 out of the mainframe.
2. Use a Phillips screwdriver to remove the four screws that secure the
bulkhead connector to the front panel (see Figure F-1).
3. Gently pull the bulkhead out of the unit and unscrew the fiber connector. Be
careful not to pull beyond the fiber slack. If there is insufficient slack or if
you accidently push the disconnected fiber back into the instrument, then
perform the following three steps:
a. Remove the screws that secure the side cover and remove the side cover
(See Figure F-1).
b. You will now have access to the optical fiber. Unscrew it from the
bulkhead if necessary or push it back through the front panel.
c. Reinstall the cover when finished.
4. Using a soft, lint-free cloth with a high-quality glass cleaner, clean the tip of
the fiber cable.
5. If available, use low-pressure compressed air or canned air to blow any dirt
out of the bulkhead connector. If compressed air is not available, then the
bulkhead will have to be taken apart and cleaned. Refer to the Changing the
Optical Port Connectors procedure, on page F–2, for information about
bulkhead disassembly.
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F–1
Appendix F: Maintenance
6. After cleaning the bulkhead, reconnect the fiber and install the bulkhead. Be
sure to reinstall the dust cover chain.
NOTE. To keep cleaning to a minimum, install the dust cover when no fiber is
connected to the optical port.
Optical Fiber Connector
Figure F-1: Removing the Optical Bulkhead Connector
Changing the Optical Port Connectors
The VXOA41 is shipped with the FC connector bulkhead and dust cover
installed. If you wish to change to the ST, DIN 47256, or SC connectors perform
the following procedure.
1. Turn the power supply off first and then pull the VXOA41 out of the
mainframe.
2. Using a Phillips screwdriver, remove the four screws that secure the
bulkhead connector to the front panel (see Figure F-1).
3. Gently pull the bulkhead out of the unit and unscrew the fiber connector. Be
careful not to pull beyond the fiber slack. If there is insufficient slack or if
you accidently push the disconnected fiber back into the instrument, then
perform the following three steps:
F–2
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Appendix F: Maintenance
a. Using a Phillips screwdriver, remove the screws that secure the side
cover and then remove the side cover (See Figure F-1).
b. You will now have access to the optical fiber. Unscrew it from the
bulkhead if necessary or push it back through the front panel.
c. Reinstall the side cover when finished.
4. Disassemble the bulkhead as shown in Figures F-2 through F-5.
Figure F-2: FC Optical Bulkhead Assembly
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F–3
Appendix F: Maintenance
Figure F-3: ST Optical Bulkhead Assembly
Figure F-4: DIN 47256 Optical Bulkhead Assembly
F–4
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Appendix F: Maintenance
Figure F-5: SC Optical Bulkhead Assembly
5. Replace the current bulkhead with the one you wish to use and re-assemble.
6. Installation is the reverse of steps 1 through 3.
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F–5
Appendix F: Maintenance
F–6
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Appendix G: Performance Verification
Equipment List
Tektronix VX1400 or VX1405 Mainframe or any VXI C-size or D-size
mainframe with a minimum cooling capacity of 1.5 liters/sec (at 0.04 mm
H2O); see the Installation section of the Getting Started chapter in this
manual.
A VXI slot-0 controller and/or Resource Manager (for example, a Tektronix
VX4521 Resource Manager or a Radisys EPC-2 controller).
A software utility to send and receive VXI, message-based commands and
queries to a VXI device: if using an EPC-2 controller this can be the
BusProbe utility; if using the VX4521 then this can be any GPIB talker-listener utility on a controller with a GPIB card (for example, an IBIC DOS or
Windows utility).
NOTE. Throughout this procedure the terms “send the command...” , “send the
query...”, and “...the query response...” refer to using this utility to send and
receive the IEEE 488.2 message-based command/queries to the VXOA41. The
actual text in this procedure that is sent to or received from the VXOA41 appears
in a different typeface, for example, .
Averaging Optical Power Meter with the following requirements:
±0.01 dB resolution
±0.005 dB stability
65 dBm sensitivity
Relative dB level to arbitrary reference capability
Sensitive (>60 dB range) at 850 nm, 1300 nm and 1550 nm
A Tektronix OCP5502 or OCP5002 can be used for the VXOA41
standard, option 1, or option 2 although the Shutter Attenuation test will
only be able to be verified to –70 dB (the OCP’s sensitivity limits the
100 dB attenuation measurement). An OCP can not be used for testing
the VXOA41 option 3 due to the OCP’s 62.5 mm fiber input and the
VXOA41 option 3’s 100 mm fiber size.
REV JUL 1993
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G–1
Appendix G: Performance Verification
G–2
A Stable Optical Source with the following requirements:
Greater than 0.01 dB stability over 1 minute
Output greater than 1 mW of optical power into the fiber type of the
VXOA41
Wavelength of 1300 ±120 nm or 1550 ±120 nm for testing VXOA41
standard module
Wavelength of 850 ±20 nm or 1300 ±20 nm or 1550 ±120 nm for testing
VXOA41 option 1, option 2, or option 3
Fiber optic jumper cables, which vary depending on the specific VXOA41 in
use:
For a standard VXOA41: two 9 µm core singlemode jumpers
For a VXOA41 option 1: One 50 µm core multimode fiber from source
to input of the VXOA41 option 1 and one 50 µm core or greater for
output of VXOA41 option 1 to the Optical Power Meter (note: 62.5 µm
is largest fiber core allowed for accurate use with the Tektronix OCP
Power Meter). The 50 µm fiber used for input to the VXOA41 option 1
can be replaced by a singlemode fiber if the stable source to be used is
designed to couple light into a singlemode fiber.
For a VXOA41 option 2: One 62.5 µm core multimode fiber from the
source to the input of VXOA41 option 2 and one 62.5 µm core or greater
for the output of the VXOA41 to the Optical Power Meter (note: since
62.5 µm is largest fiber core allowed for accurate use with the Tektronix
OCP Power Meter, the OCP should not be used with the 100 µm
VXOA41 option 3). The 62.5 µm fiber used for input to the VXOA41
option 2 can be replaced by a singlemode fiber if the stable source to be
used is designed to couple light into a singlemode fiber (a singlemode
50 µm fiber can also be used).
For VXOA41 option 3: one 100 µm core multimode fiber from source to
input of VXOA41 option 3 and one 100 µm core or greater for output of
VXOA41 option 3 to the Optical Power Meter (note: 62.5 µm is the
largest fiber core allowed for accurate use with the Tektronix OCP Power
Meter). The 100 µm fiber used for input to the VXOA41 option 3 can be
replaced by a singlemode fiber if the stable source to be used is designed
to couple light into a singlemode fiber. A 50 µm fiber, or even a 62.5 µm
fiber can be used with a stable source designed to couple into a
singlemode fiber.
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Appendix G: Performance Verification
NOTE. The equipment listed is sufficient to carry out the Performance Verification. However, the VXOA41 is an instrument capable of operating at over a
thousand different wavelength settings and at over 6000 different attenuation
level settings. This verification procedure is not intended as a comprehensive
verification of the instrument’s specifications. Please refer to the Product
Verification Data sheet accompanying the VXOA41 at shipment for a more
complete listing of the instrument’s performance as shipped from the factory.
Power Up
1. Insert the VXOA41 into a powered-down VXI Mainframe (see Installation
in the Getting Started section).
Make certain that the VXOA41 is securely inserted into the mainframe.
2. Turn the VXI mainframe power on (via mainframe’s power switch).
A few seconds are required after mainframe power-up before the slot-0
resource manager deasserts system reset and the VXOA41 READY LED
lights.
3. The wavelength and attenuation settings will power-up at whatever values
existed before the previous power-down; if the instrument is being powered
on for the first time the settings will be at their factory default values.
4. to the VXOA41; this ensures that query
responses from the instrument are prefixed in the fullest and most explanatory way (the examples of this procedure assume that the headers are turned
on).
Front Panel LEDs
NOTE. Whenever the VXOA41 is accessed over the VXI Bus with either a
command or query, the amber ACCESSED LED on the front panel should light
briefly. The length of time the LED is lighted is relatively short (tenths of
seconds), depending on the speed of the controller, but it is usually observable by
the user.
1. Check that the READY LED is lighted (green).
This should stay lighted while the mainframe is on and the controller is
not in RESET.
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G–3
Appendix G: Performance Verification
2. Send the command ATT:MIN; this causes the instrument to adjust to
zero dB (a few seconds may be needed to complete the adjustment if the
previous setting was non-zero).
The MIN ATT red LED should be lighted.
3. Send the command ; this causes the instrument to adjust to 10 dB
(a few seconds may be needed to complete the adjustment).
The ATT ADJ red LED should be lighted for a brief moment (a second
or two) while the attenuation is being adjusted. This LED will always
light up during attenuation adjustments (and after wavelength adjustments); after adjustments are complete, the LED should return to an OFF
state (unlighted).
4. Send the command ; this causes the instrument to return to the
minimum attenuation.
5. ; 6. Send the command ; this causes the instrument to adjust to place the
shutter across the optical path for maximum attenuation.
The DISABLE red LED should be lighted.
7. Send the command ; this will withdraw the shutter so that it is no
longer blocking the optical path.
G–4
The DISABLE red LED should be off (unlighted).
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Appendix G: Performance Verification
Shutter Attenuation and Disable
1. Send the command ; this causes the instrument to place the shutter
across the optical path for maximum attenuation.
VXOA41
Optical Source
Optical Power Meter
Input
Output
Output
Figure G-1: Setup for Shutter Attenuation and Disable Procedure
2. If you have not already done so, connect an optical source to the input of the
VXOA41 using an optical fiber jumper cable of equal or lesser core diameter
than the VXOA41 (see Specifications for the core diameter of the particular
VXOA41 under test).
The source should be relatively stable (>0.1 dB stability over 1 minute)
and should emit at least 1 mW of optical power into the fiber jumper
used for input to the VXOA41. The source must emit light at a
wavelength within the specifications of the VXOA41 (700 nm to
1600 nm).
An average optical power meter is required. The meter should be able to
accept the fiber type of the jumpers being used.
3. Before continuing, cap the input to the Optical Power Meter and properly
zero the meter.
4. Send the command , this withdraws the shutter from the optical path.
5. Connect a fiber of equal or greater core diameter than VXOA41 to the output
of the VXOA41.
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G–5
Appendix G: Performance Verification
6. Connect the other end of the fiber jumper to the input of the Optical Power
Meter.
7. Record the power reading from the Optical Power Meter as Po.
8. If a relative dB mode is available on the Power Meter, set the dB reference
level of the Power Meter to the measured Po value.
9. Send the command ; this causes the VXOA41 to place the shutter
across the optical path for maximum attenuation.
10. Record the new reading of the Optical Power Meter as Pf; if the dB relative
mode is available, then record the new reading’s value relative to the
P0=0 dB reference. If Pf is v0.00, substitute 1
10 –14 W for Pf. If the
Relative dB mode is not available, the relative dB is calculated as
Relative Attenuation with shuttler blocking light (dB) + 10
log
Pf
P0
The Relative Attenuation should be >100 dB lower; that is, the power
meter in relative mode should read less than –100 dB (note: for the
VXOA41 option 3, the relative level should be >90 dB lower).
NOTE. Most Optical Power Meters cannot accurately measure at such low power
levels; consequently, the meter may simply display the lowest value it possibly
can when the shutter is activated. To verify the >100 dB isolation of the shutter,
an Optical Power Meter with greater than –100 dBm sensitivity must be used.
G–6
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Appendix G: Performance Verification
Insertion Loss (Long Wavelengths)
1. Send the command ; this causes the VXOA41 to place the shutter
across the optical path for maximum attenuation.
2. Properly zero the Average Optical Power Meter to be used.
3. Send the command , this withdraws the shutter from the optical path.
VXOA41
Optical Source
Optical Power Meter
Input
Output
Output
Figure G-2: First setup for Insertion Loss Procedure
4. If you have not already done so, connect the optical source to the input of the
Average Optical Power Meter using an optical fiber jumper cable of equal or
lesser core diameter than the VXOA41.
The source should be relatively stable (>0.1 dB stability over 1 minute)
and should emit at least 1 mW of optical power into the fiber jumper
used. The source must emit light at a wavelength within the specifications of the VXOA41 long wavelength insertion loss (1100 nm to
1700 nm).
5. Record the power reading from the Optical Power Meter as Plong1.
If a relative-dB mode is available on the Power Meter, set the dB
reference level of the Power Meter to the measured Plong1 value.
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G–7
Appendix G: Performance Verification
VXOA41
Optical Source
Optical Power Meter
Input
Output
Output
Figure G-3: Second setup for Insertion Loss Procedure
6. If you have not already done so, attach the optical source to the input of the
VXOA41 using the fiber jumper.
7. Attach the output of the VXOA41 to the Optical Power Meter using a fiber
of greater than or equal core diameter compared to the VXOA41.
8. Send the command ATT:MIN to the VXOA41 (check to see that MIN ATT
LED is lighted).
9. Record the new reading of the Optical Power Meter as Plong2; if the dB
relative mode is available, then record the new reading’s value relative to the
Plong1=0dB reference. If the Relative dB mode is not available, the relative
dB Insertion Loss is calculated as:
Long Wavelength Insertion Loss (dB) + –10
G–8
log
Plong2
Plong1
The Long Wavelength Insertion Loss should be less than –2.0 dB (that
is, less than 2.0 dB Insertion Loss).
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Appendix G: Performance Verification
Insertion Loss (Short Wavelengths)
1. Properly zero the Average Optical Power Meter to be used.
VXOA41
Optical Source
Optical Power Meter
Input
Output
Output
Figure G-4: First setup for Insertion Loss Procedure
2. Connect an optical source to the input of the Average Optical Power Meter
using an optical fiber jumper cable of equal or lesser core diameter than the
VXOA41 (see page B–1 for the core diameter of the particular VXOA41
under test).
The source should be relatively stable (>0.1 dB stability over 1 minute)
and should emit at least 1 mWatt of optical power into the fiber jumper
used. The source must emit light at a wavelength within the specifications of the VXOA41 short wavelength insertion loss (700 nm to
1100 nm).
3. Ensure that the power meter’s wavelength is set to match the wavelength of
the source.
4. Record the power reading from the Optical Power Meter as Pshort1.
If a relative-dB mode is available on the Power Meter, set the dB
reference level of the Power Meter to the measured Pshort1 value.
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G–9
Appendix G: Performance Verification
VXOA41
Optical Source
Optical Power Meter
Input
Output
Output
Figure G-5: Second setup for Insertion Loss Procedure
5. Attach the optical source to the input of the VXOA41 using the fiber jumper.
6. Attach the output of the VXOA41 to the Optical Power Meter using a fiber
of greater than or equal core diameter compared to the VXOA41.
7. Ensure that the VXOA41 is set to the minimum attenuation setting; this can
be accomplished by sending the command to the VXOA41 (check
to see that MIN ATT LED is lighted).
8. Record the new reading of the Optical Power Meter as Pshort2; if the dB
relative mode is available, then record the new reading’s value relative to the
Pshort1=0 dB reference. If the Relative dB mode is not available, the relative
dB Insertion Loss is calculated as
Short Wavelength Insertion Loss (dB) + 10
G–10
log Pshort2
Pshort1
The relative level of Pshort2 to Pshort1 should be greater than –4.0 dB
(that is, less than 4.0 dB Insertion Loss).
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Appendix G: Performance Verification
Repeatability and Accuracy
Although the repeatability of the VXOA41 is specified over the entire wavelength range (600 nm–1700 nm), the <0.15 dB accuracy error (typically
<0.05 dB) specification is only specified for wavelengths within ±20 nm of
850 nm, 1300 nm, and 1550 nm. This test must be repeated three times with
three different stable optical sources at the three specified wavelengths to fully
verify the accuracy of the VXOA41. A single source is sufficient, though, to
verify the repeatability of the VXOA41.
NOTE. This test requires an Optical Source and an Average Optical Power
Meter: In order to verify the repeatability of the VXOA41, the Optical Source
and Power Meter must both be very stable (>0.01 dB); the repeatability of the
measurement devices must be greater than the value being measured. It is
necessary that the optical fibers used to carry the signal from the source, to the
VXOA41, and then to the Power Meter are not disturbed or moved during this
test.
VXOA41
Optical Source
Optical Power Meter
Input
Output
Output
Figure G-6: Setup for Repeatability and Accuracy Procedure
1. Attach the stable source to the input of the VXOA41 and attach the output of
the VXOA41 to the Optical Power Meter using the appropriate fiber optic
jumper cables. Be sure that the attenuator wavelength setting matches the
source wavelength; this can be accomplished by sending the command
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G–11
Appendix G: Performance Verification
where “<wavelength>” is a number matching the
wavelength of the stable source in units of nanometers. For example, you
might send the command: . You can check the wavelength setting
by sending the query and noting the response (in this example,
).
2. Set the VXOA41 to minimum attenuation by sending the command
.
3. After the attenuator is stable, record the optical power measured by the
Optical Power Meter; set this power level as the 0 dB reference level of the
Power Meter. Set the Optical Power Meter to display in dB.
4. Adjust the attenuation to 10.00 dB by sending the command to
the VXOA41.
5. Record the relative dB power level of the Power Meter; this value should be
–10.00 dB ±0.15 dB relative to the previously set 0 dB reference level (when
the VXOA41 was at MIN ATT setting).
Record the exact relative dB reading; this will be used as the 10 dB
comparison for repeatability.
6. Adjust the attenuation to 20.00 dB by sending the command to
the VXOA41.
7. Record the relative dB power level of the Power Meter; this value should be
–20.00 dB ±0.15 dB relative to the previously set 0 dB reference level (when
the VXOA41 was at MIN ATT setting).
Record the exact relative dB reading; this will be used as a comparison
for repeatability.
8. Adjust the attenuation to minimum attenuation by sending the command
to the VXOA41.
The Power Meter should read within ±0.05 dB of 0.00 dB; this
verification assumes that the source has not drifted (<0.005 dB change)
and the fiber jumper cables have not been disturbed.
9. Adjust the attenuation to 10.00 dB by sending the command to
the VXOA41.
The Power Meter should read within ±0.05 dB of the reading taken in
step 5; this verification assumes that the source has not drifted
(<0.005 dB change) and the fiber jumper cables have not been disturbed.
10. Adjust the attenuation to 20.00 dB by sending the command ATT:DB 20 to
the VXOA41.
G–12
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Appendix G: Performance Verification
The Power Meter should read within ±0.05 dB of the reading taken in
step 7; this verification assumes that the source has not drifted
(<0.005 dB change) and the fiber jumper cables have not been disturbed.
This completes the performance verification.
NOTE. To fully verify the accuracy of the VXOA41, you should repeat steps 1
through 10 for each of the three wavelengths described in the opening paragraph
of this procedure.
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G–13
Appendix G: Performance Verification
G–14
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Appendix H: Replaceable Parts
This appendix contains a list of the components that are replaceable for the
VXOA41 Optical Attenuator. As described below, use this list to identify and
order replacement parts.
Parts Ordering Information
Replacement parts are available from or through your local Tektronix service
center or representative.
Changes to Tektronix instruments are sometimes made to accommodate
improved components as they become available and to give you the benefit of
the latest circuit improvements. Therefore, when ordering parts, it is important to
include the following information in your order:
Part number
Instrument type or model number
Instrument serial number
Instrument modification number, if applicable
If a part you order has been replaced with a different or improved part, your local
Tektronix service center or representative will contact you concerning any
change in the part number.
Change information, if any, is located at the rear of this manual.
Using the Replaceable Parts List
The tabular information in the Replaceable Parts List is arranged for quick
retrieval. Understanding the structure and features of the list will help you find
the all the information you need for ordering replacement parts.
Item Names
Abbreviations
In the Replaceable Parts List, an Item Name is separated from the description by
a colon (:). Because of space limitations, an Item Name may sometimes appear
as incomplete. For further Item Name identification, U.S. Federal Cataloging
Handbook H6-1 can be used where possible.
Abbreviations conform to American National Standards Institute (ANSI)
standard Y1.1
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H–1
Appendix H: Replaceable Parts
CROSS INDEX – MFR. CODE NUMBER TO MANUFACTURER
Mfr.
Code
Manufacturer
Address
City, State, Zip Code
TK0435
LEWIS SCREW CO
4300 S RACINE AVE
CHICAGO IL 60609–3320
0KB05
NORTH STAR NAMEPLATE
1281–S NE 25TH
HILLSBORO OR 97124
62559
SCHROFF INC
170 COMMERCE DR
WARWICK RI 02886–2430
73743
FISCHER SPECIAL MFG CO
111 INDUSTRIAL RD
COLD SPRING KY 41076–9749
80009
TEKTRONIX INC
14150 SW KARL BRAUN DR
PO BOX 500
BEAVERTON OR 97077–0001
H–2
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Appendix H: Replaceable Parts
Fig. &
Index No.
Qty
12345 Name & Description
200–4124–00
1
COVER,SIDE:VXI C–SIZE,0.032 ALUM 5052
–2
211–0311–00
16
SCREW,MACHINE:4–40 X 0.125 L,FLH,100 DEG,STL
TK0435
ORDER BY DESC
–3
426–2489–00
2
FRAME,SECTION:RAIL,TOP & BOTTOM,ALUMINUM
80009
426248900
–4
211–0101–00
8
SCREW,MACHINE:4–40 X 0.25,FLH,100 DEG,STL
TK0435
ORDER BY DESC
–5
200–4043–00
1
COVER,SIDE:VXI C–SIZE,0.032 ALIM 5052
80009
200404300
–6
334–8657–00
1
MARKER,IDENT:MKD TEKTRONIX VXOA41 OPT ATTEN
80009
334865700
–7
210–0405–00
4
NUT,PLAIN,HEX:2–56 X 0.188,BRS
73743
12157–50
–8
367–0448–00
2
HANDLE,CARRYING:GEMINI
62559
20808–004
–9
211–0334–00
4
SCREW,SHOULDER:4–40 X 0.4,HEX HD,BRASS
80009
211033400
–10
334–8600–00
1
MARKER,IDENT:MKD VXI,VXOA41
0KB05
334–8600–00
–11
334–8595–00
1
MARKER,IDENT:MKD TEKTRONIX,VXOA41
0KB05
334–8595–00
070–8777–00
1
MANUAL,TECH:USER,VXOA41
80009
070877700
020–1885–00
1
ACCESSORY PKG:O/E CONVERTER
80009
020188500
G–1–1
Tektronix
Part No.
Serial No.
Effective Dscont
Mfr.
Code
80009
Mfr. Part No.
200412400
ACCESSORIES
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H–3
Appendix H: Replaceable Parts
Figure H-1: VXOA41 Replaceable Parts
H–4
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Glossary and Index
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Glossary
Buffer
A protective coating placed on an optical fiber.
Dispersion
The process by which an optical signal is distorted as it travels through an
optical fiber. One kind of dispersion is material dispersion, which is caused
by a differential delay of the different wavelength components of an optical
signal.
Cladding
The outer layer of an optical fiber, which surrounds the core, and has a lower
refractive index than the core.
Core
The center, light-guiding section of an optical fiber.
dBm
An expression of power level in decibels referenced to a power of one
milliwatt.
Mode
An allowable electromagnetic field pattern within an optical fiber. An
allowable pattern satisfies Maxwell’s equations.
Multimode Fiber
An optical fiber with a core that is larger enough to support the transmission
of more than one mode of light through the fiber (that is, axial and non-axial
light rays).
Numerical Aperature
A measure of the light-gathering ability of an optical fiber, which describes
the maximum angle to the fiber axis at which light will be accepted and
propagated. The numerical aperature of an optical fiber is defined as:
NA + Ǹ(n 21 * n 22)
where n1 and n2 are the refractive index of the core and the cladding,
respectively.
Singlemode Fiber
An optical fiber with a narrow core that supports the transmission of only
one mode of light through the fiber.
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Glossary–1
Glossary
Glossary–2
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Index
A
Abbreviating, Command, 3–4
Accessories
Optional, A–1, A–2
Standard, A–1
address switches, 1–3
ADJusting? command, 3–11–3–12
ALLev? command, 3–12, 3–21
Argument, Command, 3–2
ASCII, 3–1
Character table, C–2
ATTenuation command, 3–13
ATTen:DB, 3–13
ATTen:DBR, 3–13
ATTen:MINimum, 3–13
ATTenuation:INCRement command, 3–14
ATTenuation:NEXT command, 3–14–3–15
ATTenuation:TPOLarity command, 3–16
ATTenuation:TRIGger command, 3–15
B
backplane jumpers, 1–2
Block, Command argument, 3–5
BLRN command, 3–16–3–17
BNF (Backus-Naur form), 3–1
Break, 3–1
Buffer, Glossary–1
C
*CAL? command, 3–17
CAUTION
statement in manuals, v
statement on equipment, v
Cautions
fuses, vi
grounding the VXOA41, vi
operating in explosive atmospheres, vi
power cord, vi
power source, vi
removing panels or covers, vi
checkout procedure, ID?, *IDN? query, 1–6
Cladding, Glossary–1
Clear Status, 3–17–3–18
*CLS command, 3–17–3–18
Command
*CAL?, 3–17
*OPT?, 3–26
*SET?, 3–25
Abbreviating, 3–4
ADJusting?, 3–11–3–12
ALLev?, 3–12
Argument, 3–2
ATTenuation, 3–13
ATTenuation:INCRement, 3–14
ATTenuation:NEXT, 3–14–3–15
ATTenuation:TPOLarity, 3–16
ATTenuation:TRIGger, 3–15
Block argument, 3–5
BLRN, 3–16–3–17
*CLS, 3–17–3–18
Common, List, 3–9
Concatenating, 3–4
DESE, 3–18–3–19, 3–37
Device, List, 3–11
DISable, 3–19
*ESE, 3–19–3–20, 3–38
*ESR?, 3–20–3–21, 3–35
EVENt?, 3–21
EVMSg?, 3–21–3–22
EVQty?, 3–22
FACTory, 3–22–3–23
HEADER, 3–24
Header, 3–2
*IDN?, 3–24–3–25
List
Common command, 3-9
Device command, 3-11
*LRN?, 3–25
Message, 3–2
Mnemonic, 3–2
Numeric argument, 3–6
*OPC, 3–26
*PSC, 3–27, 3–38
Query, 3–1, 3–3
RECall, 3–27–3–28
REFerence, 3–28
*RST, 3–28–3–29
Separator, 3–2
Set, 3–1, 3–2
*SRE, 3–29–3–30, 3–38
*STB?, 3–30, 3–36
STOre, 3–31
Syntax, BNF (Backus-Naur form), 3–1
Table
Common command, 3-9
Device command, 3-11
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Index–1
Index
*TST?, 3–31–3–32
VERBOSE, 3–32–3–33
*WAI, 3–33
WAVelength, 3–33
Word Serial, C–3
Command syntax, BNF (Backus-Naur form), 3–1
Common command, List, 3–9
Concatenating, Command, 3–4
Configuration, Command query, 3–24–3–25
Conflicts, 3–40
cooling requirements, 1–2
Core, Glossary–1
D
DANGER, statement on equipment, v
dBm, Glossary–1
DESE command, 3–18–3–19, 3–37
DESER register, 3–18, 3–27, 3–37
Device Clear, 3–1
Device command, List, 3–11
device identification number, C–1
diagnostics, 1–6
Diagram, Syntax, 3–7
DISable command, 3–19
Dispersion, Glossary–1
Documentation, A–1
Dynamic Auto Configure, 1–3–1–5
E
H
Header
Command, 3–2
Included in query response, 3–24, 3–32–3–33
HEADer command, 3–24
I
*IDN? query, 3–24–3–25
IEEE Std. 488.2 - 1987, 3–9
IEEE Std. 488.2 — 1987, 3–1
installation, module, 1–3–1–5
installation procedures, 1–2–1–5
L
LED
Accessed, 2–1
ATT ADJ, 2–1
DISABLE, 2–1
MIN ATT, 2–1
module status, 2–1
Ready, 1–6, 2–1
List
Common command, 3–9
Device command, 3–11
*LRN? query, 3–25
M
EOI (end of input), 3–5
Error message, Programming interface, 3–41
*ESE command, 3–19–3–20. 3–38
ESER register, 3–19, 3–27, 3–38
*ESR? command, 3–20–3–21
*ESR? query, 3–35
Event handling, 3–40
Event Quantity query, 3–22
Event query, 3–21–3–22
Event queue, 3–21–3–22, 3–39
EVENt? command, 3–21
EVMSg? command, 3–21–3–22
EVQty? command, 3–22
Manuals, A–1
manufacturer identification number, C–1
Message
Command, 3–2
Command terminator, 3–5
Table of program messages, 3–41
Mnemonic, Command, 3–2
Mode, Glossary–1
module installation, 1–3–1–5
Multi-mode Fiber, Glossary–1
N
Numeric, Command argument, 3–6
Numerical Aperature, Glossary–1
F
FACTory command, 3–22–3–23
front-panel, description, 2–1–2–2
Index–2
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Index
O
*OPC command, 3–26
Operation complete command, 3–26
Operation complete wait, 3–33
*OPT? command, 3–26
Optical Cables, optional accessories, A–1
Optical Connector Kit, optional accessories, A–2
Optical Output, vi
Output queue, 3–39
P
power requirements, 1–2
Power-on status clear command, 3–27
*PSC command, 3–27, 3–38
SESR register, 3–17, 3–20–3–21, 3–26, 3–35
Set
Command query, 3–25
Query, 3–25
Set command, 3–1, 3–2
*SET? query, 3–25
Single-mode Fiber, Glossary–1
*SRE command, 3–29–3–30, 3–38
SRER register, 3–27, 3–29–3–30, 3–38
*STB? query, 3–30, 3–36
STORe command, 3–31
See also RECall command
Syntax
BNF (Backus-Naur form), 3–1
Diagram, 3–7
system resource manager, 1–3
T
Q
Query, Header in query response, 3–24, 3–32–3–33
Query command, 3–1, 3–3
Queue
Event, 3–39
Output, 3–39
R
Ready LED, 1–6
RECall command, 3–27–3–28
REFerence command, 3–28
Register
DESER, 3–18, 3–27, 3–37
ESER, 3–19, 3–27, 3–38
SBR, 3–30, 3–36
SESR, 3–17, 3–20–3–21, 3–26, 3–35
SRER, 3–27, 3–29–3–30, 3–38
removing the module, 1–5
Reset
See also FACTORY
Command, 3–28–3–29
*RST command, 3–28–3–29
S
Safety, Symbols, v
SBR register, 3–30, 3–36
Self test, 3–31–3–32
Separator, Command, 3–2
Serial poll, 3–36
Service request enable command, 3–29–3–30
Service request enable register, 3–29–3–30
Table
ASCII character, C–2
Common command, 3–9
Device command, 3–11
Programming message, 3–41
Tek Std. Codes and Formats 1989, 3–9
Terminator, Command message, 3–5
*TST? query, 3–31–3–32
V
VERBOSE command, 3–32–3–33
VXI mainframe, 1–2
backplane jumpers, 1–2
VXIbus specification version, C–1
W
*WAI command, 3–33
Wait for operation complete, 3–33
WARNING, statement in manual, v
Warning, optical output, vi
WAVelength command, 3–33
Word Serial Commands
Abort Normal Operation, C–3
Assign Interrupter Line, C–3
Asynchronous Mode Control, C–3
Begin Normal Operation, C–3
Byte Available, C–3
Byte Request, C–3
Clear, C–3
Clear Lock, C–3
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Index–3
Index
Control Event, C–4
End Normal Operation, C–4
Read Interrupter Line, C–4
Read Interrupters, C–4
Read Protocol, C–4
Read Protocol Error, C–4
Read STB, C–4
Set Lock, C–4
Trigger, C–4
word serial protocol, 1–1
Index–4
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SUPPORTED
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SECURE ASSET SOLUTIONS
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at our full-service, in-house repair center
WE BUY USED EQUIPMENT
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