Keysight (Agilent) 8156A Operations Guide

Operating and Programming Guide

HP 8156A Attenuator

SERIAL NUMBERS

This guide applies to all instruments.

ABCDE

HP Part No. 08156-91011

Printed in the Federal Republic of Germany

First Edition

E1098

Notices

This document contains proprietary

information that is protected by

copyright. All rights are reserved.

No part of this document may be

photocopied, reproduced, or

translated to another language

without the prior written consent of

Hewlett-Packard GmbH.

c



Copyright 1996, 1998 by:

Hewlett-Packard GmbH

Herrenberger Str. 130

71034 Boeblingen

Germany

Subject Matter

The information in this document is

subject to change without notice.

Hewlett-Packard makes no warranty

of any kind with regard to this

printed material, including, but not

limited to, the implied warranties of

merchantability and tness for a

particular purpose.

Hewlett-Packard shall not be liable

for errors contained herein or for

incidental or consequential damages

in connection with the furnishing,

performance, or use of this material.

Printing History

New editions are complete revisions

of the guide reecting alterations in

the functionality of the instrument.

Updates are occasionally made to

the guide between editions. The

date on the title page changes when

an updated guide is published. To

nd out the current revision of the

guide, or to purchase an updated

guide, contact your Hewlett-Packard

representative.

Control Serial Number: First Edition

applies directly to all instruments.

Warranty

This Hewlett-Packard instrument

product is warranted against defects

in material and workmanship for a

period of one year from date of

shipment. During the warranty

period, HP will, at its option, either

repair or replace products that prove

to be defective.

For warranty service or repair, this

product must be returned to a service

facility designated by HP. Buyer shall

prepay shipping charges to HP and

HP shall pay shipping charges to

return the product to Buyer.

However, Buyer shall pay all shipping

charges, duties, and taxes for

products returned to HP from

another country.

HP warrants that its software and

rmware designated by HP for use

with an instrument will execute its

programming instructions when

properly installed on that instrument.

HP does not warrant that the

operation of the instrument,

software, or rmware will be

uninterrupted or error free.

Limitation of Warranty

The foregoing warranty shall not

apply to defects resulting from

improper or inadequate maintenance

by Buyer, Buyer-supplied software or

interfacing, unauthorized

modication or misuse, operation

outside of the environmental

specications for the product, or

improper site preparation or

maintenance.

No other warranty is expressed or

implied. Hewlett-Packard specically

disclaims the implied warranties of

Merchantability and Fitness for a

Particular Purpose.

First Edition : 1st January 1994 : 08156-91011 : E0194

: 1st June 1994 : 08156-91011 : E0694

: 1st March 1996 : 08156-91011 : E0396

: 1st June 1996 : 08156-91011 : E0696

: 1st October 1998 : 08156-91011 : E1098

Exclusive Remedies

The remedies provided herein are

Buyer's sole and exclusive remedies.

Hewlett-Packard shall not be liable

for any direct, indirect, special,

incidental, or consequential

damages whether based on contract,

tort, or any other legal theory.

Assistance

Product maintenance agreements

and other customer assistance

agreements are available for

Hewlett-Packard products.For any

assistance contact your nearest

Hewlett-Packard Sales and Service

Oce.

Certication

Hewlett-Packard Company certies

that this product met its published

specications at the time of

shipment from the factory.

Hewlett-Packard further certies

that its calibration measurements

are traceable to the United States

National Institute of Standards and

Technology, NIST (formerly the

United States National Bureau of

Standards, NBS) to the extent

allowed by the Institutes's

calibration facility, and to the

calibration facilities of other

International Standards Organization

members.

ISO 9001 Certication

Produced to ISO 9001 international

quality system standard as part of

our objective of continually

increasing customer satisfaction

through improved process control.

Safety Summary

The following general safety precautions must be observed during all phases

of operation, service, and repair of this instrument. Failure to comply with

these precautions or with specic warnings elsewhere in this manual violates

safety standards of design, manufacture

, and intended use of the instrument.

Hewlett-Packard Company assumes no liability for the customer's failure to

comply with these requirements.

General

This is a Safety Class 1 instrument (provided with terminal for

protective earthing) and has been manufactured and tested according to

international safety standards.

Operation - Before applying power

Comply with the installation section.

Additionally, the following shall be observed:

Do not remove instrument covers when operating.

Before the instrument is switched on, all protective earth terminals

, extension

cords, auto-transformers and devices connected to it should be connected to a

protective earth via a ground socket. Any interruption of the protective earth

grounding will cause a potential shock hazard that could result in serious

personal injury.

Whenever it is likely that the protection has been impaired, the instrument

must be made inoperative and be secured against any unintended operation.

Make sure that only fuses with the required rated current and of the specied

type (normal blow, time delay, etc.) are used for replacement. The use of

repaired fuses and the short-circuiting of fuseholders must be avoided.

Adjustments described in the manual are performed with power supplied to

the instrument while protective covers are removed. Be aware that energy at

many points may, if contacted, result in personal injury.

Any adjustments, maintenance, and repair of the opened instrument under

voltage should be avoided as much as possible, and when unavoidable, should

be carried out only by a skilled person who is aware of the hazard involved.

Do not attempt internal service or adjustment unless another person, capable

of rendering rst aid and resuscitation is present. Do not replace components

with power cable connected.

Do not operate the instrument in the presence of ammable gases or fumes.

Operation of any electrical instrument in such an enviroment constitutes a

denite safety hazard.

Do not install substitute parts or perform any unauthorized modication to

the instrument.

Be aware that capacitors inside the instrument may still be charged even if

the instrument has been disconnected from its source of supply.

v

Safety Symbols

The apparatus will be marked with this symbol when it is

necessary for the user to refer to the instruction manual in

order to protect the apparatus against damage.

Caution, risk of electric shock.

Frame or chassis terminal.

Protective conductor terminal.

Hazardous laser radiation.

Warning

Caution

The Models HP 8156A is a Class 1 instrument (that is, an instrument with an

exposed metal chassis directly connected to earth via the power supply cable).

The symbol used to show a protective earth terminal in the instrument is .

Before operation, review the instrument and guide, including the red safety

page, for safety markings and instructions. Consult the installation section. You

must follow these instructions and indications to ensure safe operation and to

maintain the instrument in safe condition.

The WARNING sign denotes a hazard. It calls attention to

a procedure, practice or the like, which, if not correctly

performed or adhered to, could result in injury or loss of

life. Do not proceed beyond a WARNING sign until the

indicated conditions are fully understood and met.

The CAUTION sign denotes a hazard. It calls attention to

an operating procedure, practice or the like, which, if not

correctly performed or adhered to, could result in damage to

or destruction of part or all of the equipment. Do not proceed

beyond a CAUTION sign until the indicated conditions are fully

understood and met.

vi

Warning

AC Line Power Requirements

To avoid hazardous electrical shock, do not operate the

instrument if there are any signs of damage to any portion

of the outer enclosure (covers, panels, etc.).

The HP 8156A can operate from any single-phase A

between 100V and 240V at a frequency in the range from 50 to 60Hz. The

maximum power consumption is 40VA with all options installed.

There is a fuse in this instrument. This is a T1A/250V (time-lag) (HP Part No.

2110-0007). See \Replacing the Fuse" in Appendix A for instructions on how to

change the fuse.

Line Power Cable

In accordance with international safety standards, this instrument has

a three-wire power cable. When connected to an appropriate AC power

receptacle, this cable earths the instrument cabinet. The type of power cable

shipped with each instrument depends on the country of destination. Refer to

Figure 0-1 for the part numbers of the power cables available.

C power source that supplies

Figure 0-1. Line Power Cables - Plug Identication

vii

Warning

To avoid the possibility of injury or death, you must

observe the following precautions before powering on the

instrument.

If this instrument is to be energized via an

autotransformer for voltage reduction, ensure that the

Common terminal connects to the earthed pole of the

power source.

Insert the power cable plug only into a socket outlet

provided with a protective earth contact. Do not negate

this protective action by the using an extension cord

without a protective conductor.

Before switching on the instrument, the protective

earth terminal of the instrument must be connected to a

protective conductor.You can do this by using the power

cord supplied with the instrument.

It is prohibited to interrupt the protective earth

connection intentionally.

The following work should be carried out by a qualied electrician. All local

electrical codes must be strictly observed:

If the plug on the cable does not t the power outlet, or if the cable is to be

attached to a terminal block, cut the cable at the plug end and rewire it.

The color coding used in the cable depends on the cable supplied. If you are

connecting a new plug, it should meet the local safety requirements and include

the following features:

Adequate load-carrying capacity (see table of specications).

Ground connection.

Cable clamp.

Warning

To avoid the possibility of injury or death, please note that

the HP 8156A does not have a oating earth.

viii

Warning

The HP 8156A is not designed for outdoor use.To prevent

potential re or shock hazard, do not expose the instrument

to rain or other excessive moisture.

ix

Contents

1. Getting Started

Using the Attenuator ..................... 1-1

Using the Modify Keys . . . . . . . . . . . . . . . . . . . . 1-2

Editing a Number ........ ...... ...... . 1-3

Editing a Non-Numeric Parameter ............. 1-3

Making an Attenuation Sweep .... ...... ..... .. 1-3

Making an Automatic Sweep ................. 1-3

The Manual Sweep . . . . . . . . . . . . . . . . . . . . . . .

Using your Attenuator as a Variable Back Reector ....... 1-4

Using the Through-Power Mode . . . . . . . . . . . . . . . . . 1-5

Selecting the Wavelength Calibration and Its Function ...... 1-6

2. Using the Attenuator

Setting Up the Hardware . . . . . . . . . . . . . . . . . . . . 2-1

Setting Up the Attenuation . . . . . . . . . . . . . . . . . . . 2-2

Entering the Attenuation Factor ...... ..... .... 2-2

Resetting the Attenuation Factor . . . . . . . . . . . . . . 2-3

Entering a Calibration Factor . . . . . . . . . . . . . . . . . 2-3

Editing the Calibration Factor ........ ...... . 2-3

Resetting the Calibration Factor ...... ..... .. 2-4

Transferring to the Calibration Factor . . . . . . . . . . . . 2-4

Entering the Wavelength . . . . . . . . . . . . . . . . . . . 2-4

Resetting the Wavelength ................. 2-5

Example, Setting the Calibration ...... ...... .... 2-5

1-4

3. Making an Attenuation Sweep

Conguring the Hardware ...... ...... ...... . 3-1

The Automatic Sweep ..................... 3-2

Setting Up an Automatic Sweep ...... ...... ... 3-2

Starting the Setting Up . . . . . . . . . . . . . . . . . . . 3-3

Editing the Parameters . . . . . . . . . . . . . . . . . . . 3-3

Resetting the Parameters . . . . . . . . . . . . . . . . . . 3-3

Contents-1

Executing the Automatic Sweep ............... 3-4

Repeating the Sweep . . . . . . . . . . . . . . . . . . . . 3-4

Restarting the Sweep ................... 3-4

The Manual Sweep . . . . . . . . . . . . . . . . . . . . . . . 3-5

Setting Up a Manual Sweep ...... ...... ..... 3-5

Starting the Setting Up . . . . . . . . . . . . . . . . . . . 3-5

Editing the Parameters . . . . . . . . . . . . . . . . . . . 3-5

Resetting the Parameters . . . . . . . . . . . . . . . . . . 3-6

Executing the Manual Sweep . . . . . . . . . . . . . . . . . 3-6

Changing the Attenuation in a Manual Sweep . . . . . . . . 3-7

Example,anAutomatic Attenuation Sweep .... ...... . 3-7

4. Using your Attenuator as a Variable Back Reector

Conguring the Hardware .. ...... ...... ..... 4-1

Setting Up the Software .................... 4-2

Editing the Setup ...................... 4-2

Resetting the Parameters . . . . . . . . . . . . . . . . . . 4-3

Executing the Back Reector Application . . . . . . . . . . . 4-3

Example, Setting a Return Loss . . . . . . . . . . . . . . . . . 4-4

5. Setting Up the System

Setting the HP-IB Address .. ...... ...... ..... 5-1

Resetting the HP-IB Address ................. 5-1

Selecting the HP-IB Command Set .. ...... ...... . 5-1

Resetting the Command Set .. ...... ...... ... 5-2

Selecting the Wavelength Calibration and Its Function ...... 5-2

Setting the Function of the Wavelength Calibration ...... 5-2

Resetting the Function of the Wavelength Calibration Data . . 5-3

Selecting the Wavelength Calibration Data . . . . . . . . . . . 5-3

Resetting the Wavelength Calibration Data Set . . . . . . . . 5-4

Selecting the Through-Power Mode ...... ..... .... 5-4

Deselecting the Through-Power Mode . . . . . . . . . . . . . 5-5

Resetting the Through-Power Mode . . . . . . . . . . . . . . 5-5

Setting the Display Brightness .. ...... ...... ... 5-6

Resetting the Display Brightness ............... 5-6

Selecting the Setting used at Power-On ............. 5-6

Resetting the Power-On Setting . . . . . . . . . . . . . . . . 5-6

5

Locking Out

Resetting the

4

Enb/Dis

...................... 5-7

5

4

Enb/Dis

Lock Out . . . . . . . . . . . . . . . . 5-7

Selecting the Shutter State at Power On . . . . . . . . . . . . . 5-7

Resetting the Shutter State at Power On ........... 5-7

Contents-2

Setting the Display Resolution .. ...... ...... ... 5-8

Resetting the Display Resolution ............... 5-8

6. Storing and Recalling Settings

Storing the Setting . . . . . . . . . . . . . . . . . . . . . . . 6-1

Recalling a Setting . . . . . . . . . . . . . . . . . . . . . . . 6-1

Resetting the Instrument . . . . . . . . . . . . . . . . . . . 6-1

Recalling a User Setting ................... 6-2

7. Programming the Attenuator

HP-IB Interface ........................ 7-1

Setting the HP-IB Address ...... ...... ...... . 7-3

Returning the Instrument to Local Control ........... 7-3

How the Attenuator Receives and Transmits Messages . . . . . . 7-3

How the Input Queue Works ................. 7-3

Clearing the Input Queue . . . . . . . . . . . . . . . . . . 7-4

The Output Queue . . . . . . . . . . . . . . . . . . . . . . 7-4

The Error Queue . . . . . . . . . . . . . . . . . . . . . . . 7-4

Some Notes about Programming and Syntax Diagram Conventions 7-5

Short Form and Long Form.................. 7-5

Command and Query Syntax ................. 7-5

8. Remote Commands

Units .............................

Command Summary ...................... 8-2

The Common Commands . . . . . . . . . . . . . . . . . . . . 8-5

Common Status Information ................. 8-5

SRQ, The Service Request ................. 8-6

*CLS ............................ 8-7

*ESE ............................ 8-7

*ESE? . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8

*ESR? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-8

*IDN? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-9

*OPC . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-10

*OPC? ...... ...... ...... ...... .. 8-10

*OPT? .... ...... ...... ...... ..... 8-10

*RCL ............................ 8-11

*RST ............................ 8-11

*SAV ............................ 8-12

*SRE ............................ 8-13

*SRE? . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13

8-1

Contents-3

*STB? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-14

*TST? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-14

*WAI ...... ...... ...... ...... .... 8-15

DISPlay Commands ...................... 8-16

:DISPlay:BRIGhtness . . . . . . . . . . . . . . . . . . . . . 8-16

:DISPlay:ENABle ...................... 8-16

INPut Commands .. ...... ..... ...... .... 8-18

:INPut:ATTenuation ..................... 8-18

:INPut:LCMode ....................... 8-19

:INPut:OFFSet . . . . . . . . . . . . . . . . . . . . . . . . 8-19

:INPut:OFFSet:DISPlay . . . . . . . . . . . . . . . . . . . . 8-20

:INPut:WAVelength . . . . . . . . . . . . . . . . . . . . . . 8-20

OUTPut Commands ...... ...... ...... .... 8-22

:OUTPut:APMode ...................... 8-22

:OUTPut:POWer ....................... 8-23

:OUTPut:[:STATe] .... ...... ...... ...... 8-24

:OUTPut:[:STATe]:APOWeron . . . . . . . . . . . . . . . . . 8-25

STATus Commands . . . . . . . . . . . . . . . . . . . . . . . 8-26

:STATus:OPERation:CONDition? ............... 8-27

:STATus:OPERation:ENABle ................. 8-28

:STATus:OPERation[:EVENt]? . . . . . . . . . . . . . . . . . 8-28

:STATus:OPERation:NTRansition .... ...... ..... 8-29

:STATus:OPERation:PTRansition ...............

8-29

:STATus:QUEStionable:CONDition? .............. 8-30

:STATus:QUEStionable:ENABle . . . . . . . . . . . . . . . . 8-30

:STATus:QUEStionable[:EVENt]? ............... 8-30

:STATus:QUEStionable:NTRansition . . . . . . . . . . . . . . 8-31

:STATus:QUEStionable:PTRansition . . . . . . . . . . . . . . 8-31

:STATus:PRESet ...... ...... ...... ..... 8-32

SYSTem Commands ...... ...... ..... ..... 8-33

:SYSTem:ERRor? . . . . . . . . . . . . . . . . . . . . . . . 8-33

User Calibration Commands ...... ...... ...... 8-34

Entering the User Calibration Data .. ...... ...... 8-34

:UCALibration:STARt ................... 8-35

:UCALibration:STATe.................... 8-36

:UCALibration:STOP . . . . . . . . . . . . . . . . . . . . 8-36

:UCALibration:VALue ................... 8-37

Contents-4

9. Programming Examples

Example 1 - Checking Communication ............. 9-2

Example 2 - Status Registers and Queues ............ 9-3

Example 3 - Measuring and Including the Insertion Loss ..... 9-7

Example 4 - Running an Attenuation Sweep . . . . . . . . . . . 9-11

A. Installation

Safety Considerations ..................... A-1

Initial Inspection . . . . . . . . . . . . . . . . . . . . . . . . A-1

AC Line Power Supply Requirements ........ ...... A-2

Line Power Cable ...... ...... ..... ..... A-2

Replacing the Battery .................... A-3

Replacing the Fuse . . . . . . . . . . . . . . . . . . . . . . A-4

Operating and Storage Environment ........ ...... A-5

Temperature . . . . . . . . . . . . . . . . . . . . . . . . . A-5

Humidity .......................... A-6

Instrument Positioning and Cooling . . . . . . . . . . . . . . A-6

Switching on the Attenuator ...... ...... ...... A-6

Monitor Output .. ...... ...... ...... .... A-7

Optical Output . . . . . . . . . . . . . . . . . . . . . . . . . A-7

Disabling the Optical Output .... ...... ...... . A-7

HP-IB Interface ........................ A-8

Connector . . . . . . . . . . . . . . . . . . . . . . . . . .

HP-IB Logic Levels . . . . . . . . . . . . . . . . . . . . . .

Claims and Repackaging .................... A-9

Return Shipments to HP ................... A-9

A-8

A-9

B. Accessories

Instrument and Options .................... B-1

HP-IB Cables and Adapters . . . . . . . . . . . . . . . . . . . B-2

Connector Interfaces and Other Accessories . . . . . . . . . . . B-2

Straight Contact Connector . . . . . . . . . . . . . . . . . . B-2

Option 201, Angled Contact Connector ............ B-4

C. Specications

Denition of Terms .. ...... ...... ..... ... C-1

Specications ......................... C-3

Supplementary Performance Characteristics . . . . . . . . . . C-5

Operating Modes . . . . . . . . . . . . . . . . . . . . . . C-5

General . . . . . . . . . . . . . . . . . . . . . . . . . . C-6

Environmental ...................... C-6

Contents-5

Power: .... ...... ...... ...... .... C-7

Other Specications ...................... C-8

Declaration of Conformity ................... C-9

D. Performance Tests

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . D-1

Equipment Required . . . . . . . . . . . . . . . . . . . . . . D-1

Test Record .......................... D-3

Test Failure .......................... D-3

Instrument Specication .................... D-3

Performance Test .... ...... ...... ...... . D-4

I. Total Insertion Loss Test .................. D-4

II. Linearity/Attenuation Accuracy Test ............ D-7

III. Attenuation Repeatability Test .............. D-9

IV. Return Loss Test ...... ...... ...... ... D-9

Options 100, 101, and 121 .... ...... ...... . D-9

Options 201 and 221 . . . . . . . . . . . . . . . . . . . . D-12

V.Polarization Dependent Loss (PDL): Optional ......... D-15

Polarization Dependant Loss Test (Mueller method) ...... D-16

E. Cleaning Procedures

Cleaning Materials . . . . . . . . . . . . . . . . . . . . . . .

Cleaning Fiber/Front-Panel Connectors ............. E-2

Cleaning Connector Interfaces ................. E-2

Cleaning Connector Bushings . . . . . . . . . . . . . . . . . . E-3

Cleaning Detector Windows .................. E-3

Cleaning Lens Adapters ...... ...... ...... .. E-3

Cleaning Detector Lens Interfaces ............... E-4

E-1

F. HP-IB Overview

HP 8157A HP-IB Command Summary . . . . . . . . . . . . . . F-1

Dierences .......................... F-1

G. Error Messages

Display Messages ........ ...... ...... ... G-1

HP-IB Messages ........ ...... ...... .... G-2

Command Errors . . . . . . . . . . . . . . . . . . . . . . . G-2

Execution Errors ........ ...... ...... .. G-5

Device-Specic Errors .................... G-6

Query Errors ........................ G-7

Instrument Specic Errors .................. G-8

Contents-6

Index

Contents-7

Figures

0-1. Line Power Cables - Plug Identication ............ vii

1-1. The Attenuator Keys . . . . . . . . . . . . . . . . . . . . . 1-2

1-2. The Modify Keys . . . . . . . . . . . . . . . . . . . . . . . 1-2

1-3. The Parameters for an Automatic Sweep ........... 1-3

1-4. The Hardware Conguration for the Back Reector (Options 201

and 203) . . . . . . . . . . . . . . . . . . . . . . . . .

2-1. The Hardware Conguration for the Attenuator . . . . . . . .

2-2. The Attenuation Factor on the Display ...... ...... 2-2

2-3. The Calibration Factor on the Display . . . . . . . . . . . . .

2-4. The Wavelength on the Display . . . . . . . . . . . . . . . .

2-5. Hardware Conguration for Attenuation Example - A .... . 2-6

2-6. Hardware Conguration for Attenuation Example - B .. ... 2-7

3-1. The Hardware Conguration for the Attenuator . . . . . . . . 3-1

3-2. The Parameters for an Automatic Sweep ........... 3-2

3-3. Selecting the Automatic Sweep Application .......... 3-3

3-4. Running the Automatic Sweep ................ 3-4

3-5. Editing the

STOP

Parameter .. ...... ...... ... 3-5

3-6. Running the Manual Sweep . . . . . . . . . . . . . . . . . . 3-6

4-1. The Hardware Conguration for the Back Reector ...... 4-1

4-2. Editing the Value for the Reference Return Loss . . . . . . . . 4-3

4-3. Executing the Back Reector Application . . . . . . . . . . . 4-4

4-4. Hardware Conguration for Variable Return Loss ....... 4-4

5-1. The

5-2. The

LAMBDCAL

USERCAL

Indicator on the Display . . . . . . . . . . . . 5-3

Indicator on the Display .. ...... .... 5-4

5-3. The Display in Through-Power Mode ...... ...... . 5-5

6-1. The Display when Recalling the Default Setting ........ 6-2

8-1. Common Status Registers . . . . . . . . . . . . . . . . . . . 8-6

8-2. The Status Registers . . . . . . . . . . . . . . . . . . . . . 8-27

9-1. Hardware Conguration for Attenuation Example - A .... . 9-7

9-2. Hardware Conguration for Attenuation Example - B .. ... 9-8

A-1. Line Power Cables - Plug Identication ............ A-2

A-2. Rear Panel Markings . . . . . . . . . . . . . . . . . . . . . A-3

1-4

2-1

2-3

2-5

Contents-8

A-3. Releasing the Fuse Holder .................. A-4

A-4. The Fuse Holder . . . . . . . . . . . . . . . . . . . . . . . A-5

A-5. Correct Positioning of the Attenuator . . . . . . . . . . . . . A-6

A-6. HP-IB Connector . . . . . . . . . . . . . . . . . . . . . . . A-8

B-1. Straight Contact Connector Conguration . . . . . . . . . . . B-3

B-2. Angled Contact Connector Conguration ........... B-4

D-1. Total Insertion Loss Test Setup 1, Options 100, 101, 121 .... D-5

D-2. Total Insertion Loss Test Setup 1, Options 201, 221 . . . . . . . D-5

D-3. Total Insertion Loss Test Setup 1, Option 350 ......... D-6

D-4. Total Insertion Loss Test Setup 2, Options 100, 101, 121 .... D-6

D-5. Total Insertion Loss Test Setup 2, Options 201, 221 . . . . . . . D-7

D-6. Total Insertion Loss Test Setup 2, Option 350 ......... D-7

D-7. Return Loss Test Setup 1 (see also the text above), Options 100,

101, 121 . . . . . . . . . . . . . . . . . . . . . . . . . D-10

D-8. Return Loss Test Setup 2, Options 100, 101 ...... .... D-11

D-9. Return Loss Test Setup 2, Option 121 ............. D-12

D-10. Return Loss Test Setup 1 (see also the text above), Options 201,

221 .... ...... ...... ...... ..... D-12

D-11. Return Loss Test Setup 2, Option 201 ............. D-14

D-12. Return Loss Test Setup 2, Option 221 ............. D-14

D-13. PDL Test Setup 1: Reference Measurement .......... D-16

D-14. PDL Test Setup 2: Power after DUT . . . . . . . . . . . . . . D-22

Contents-9

Tables

7-1. HP-IB Capabilities .. ...... ...... ...... .. 7-2

8-1. Units and Allowed Mnemonics ................ 8-1

8-2. Common Command Summary . . . . . . . . . . . . . . . . . 8-2

8-3. Command List . . . . . . . . . . . . . . . . . . . . . . . . 8-3

8-4. Reset State (Default Setting) ................. 8-12

A-1. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . A-5

C-1. ............................... C-3

C-2. Monitor Output Options ................... C-4

C-3. Multimode Options . . . . . . . . . . . . . . . . . . . . . .

D-1. Equipment for the PDL test .. ...... ...... ... D-15

D-2. Performance Test HP 8156A ................. D-24

F-1. Settings (Listener Function) ................. F-2

F-2. Interrogating Settings (Talker Function) . . . . . . . . . . . . F-3

F-3. Status and Error Reporting (Talker Function) .... ..... F-4

F-4. Universal Commands . . . . . . . . . . . . . . . . . . . . . F-5

C-5

Contents-10

Getting Started

This chapter introduces the features of the HP 8156A. More detail is given on

these features in the following chapters.

The main features of the HP 8156A, other than its use as an attenuator, are its

built-in sweep and back reector applications, its through-power mode (which

displays the power at the output of the instrument, rather than the amount of

attenuation set) and its selection of wavelength calibration possibilities

Using the Attenuator

.

1

1

Note

Set the attenuation of the lter using

and

4

5

(calibration factor).

Cal

Before using the instrument, you should make sure that it is

properly warmed up. The instrument is properly warmed up

when it has been switched on for a minimum of 45 minutes.

Failure to do this can cause errors of up to 0.04dB in the

attenuation.

5

(attenuation factor),

4

Att

45

(wavelength),

Getting Started 1-1

1

Figure 1-1. The Attenuator Keys

The attenuation factor and the calibration factor set the position of the lter.

The calibration factor allows you to oset the value of the attenuation factor.

Att(dB)=Cal(dB)+Attenuation

5

In addition, you can use

the calibration factor.

Using the Modify Keys

There are four modify keys on the front panel of the attenuator.

4

Disp!Cal

Figure 1-2. The Modify Keys

to transfer the current attenuation factor to

lter

(dB)

1-2 Getting Started

Editing a Number

Use

4(5

and

4)5

to move the cursor from digit to digit when editing a number.

Use

4*5

and

4+5

to change the value of a digit when editing a number.

Editing a Non-Numeric Parameter

Use

Use

4*5or4)5

4+5or4(5

to increment the parameter.

to decrement the parameter.

Making an Attenuation Sweep

There are two types of attenuation sweep, automatic and manual.

Making an Automatic Sweep

An automatic sweep is one where stepping from one attenuation factor to the

next is done by the instrument.

1

To select the automatic sweep press

AUTO

. By pressing

the sweep.

START

4

5

repeatedly you view and can edit the parameters for

Swp

is the attenuation factor at which the sweep begins,

the attenuation factor that ends the sweep,

factor change, and

DWELL

is the time taken for each attenuation factor.

4

5

, and make sure that

Swp

STEP

Figure 1-3. The Parameters for an Automatic Sweep

If you have set up your sweep, then you press

SWEEP

is set to

is the size of the attenuation

5

to run it.

4

Exec

Getting Started 1-3

STOP

is

1

The Manual Sweep

A manual sweep is one where stepping from one attenuation factor to the next

is done by the user

To select the manual sweep press

MANUAL

. By pressing

for the sweep.

STOP

is the attenuation factor that ends the sweep, and

.

START

5

, and make sure that

4

Swp

5

repeatedly you can view and edit the parameters

4

Swp

SWEEP

is set to

is the attenuation factor at which the sweep begins,

STEP

is the size of the

attenuation factor change.

If you have set up your sweep, then you press

next attenuation factor in the sweep, press

attenuation factor in the sweep, press

4

+

5or4

4

5

Exec

4*5or4)5

5

.

(

to run it. To go to the

.To go to the previous

Using your Attenuator as a Variable Back Reector

Note

Before using the instrument, you should make sure that it is

properly warmed up. The instrument is properly warmed up

when it has been switched on for a minimum of 45 minutes.

Failure to do this can cause errors of up to 0.04dB in the

attenuation.

To use the attenuator as a back reector, you need to set up the hardware as

shown in the gure below.

Figure 1-4.

The Hardware Conguration for the Back Reector (Options 201 and 203)

Press

4

Back Re

measured values for the insertion loss of the attenuator (

5

to start operation as a back reector.You need to enter

INS LOSS

), the return

1-4 Getting Started

1

loss of the attenuator (

(

RL REF

RL(dB)=0

). The return loss (RL) is calculated according to the equation

10log(10

RL INPUT

0

RLInput(dB

10

), and the reference return loss you are using

0

(2(

)

+(1010

0

RLInput(dB

10

)

)10

Att(dB)+InsLoss(dB

10

))+

RLRef(dB

You edit the value for the return loss while the application is running.

Using the Through-Power Mode

Note

Before using the instrument, you should make sure that it is

properly warmed up. The instrument is properly warmed up

when it has been switched on for a minimum of 45 minutes

.

Failure to do this can cause errors of up to 0.04dB in the

attenuation.

In the through-power mode, the instrument shows the power that gets through

the attenuator on the display (that is the power at the output) rather than the

attenuation.

When you select the through-power mode the attenuation factor (in dB)

becomes the value for the through-power (in dBm).

Set the calibration factor (see \Entering a Calibration Factor" in Chapter 2) to

get the attenuation factor to the value of the through-power

.

))

)

After measuring and setting this base power value, press

until

THRUPOWR

is shown at the bottom of the display. SelectONto select the

through-power mode.

Edit the through-power factor by pressing

4

5

, and then the Modify keys.

Att

4

Syst

5

repeatedly

Getting Started 1-5

1

Selecting the Wavelength Calibration and Its Function

The attenuation at any point on the lter is wavelength dependent. This

dependence is measured and stored in the instrument, and is used, with

the value for the wavelength entered by the user to compensate for the

dependence. This is the wavelength calibration data.

There are two ways in which this data can be used:

to reposition the lter so that the attenuation stays constant, or

to change the attenuation factor on the display to show the wavelength

dependence.You use this to set the wavelength for an unknown source (you

alter the wavelength until the displayed attenuation matches the measured

attenuation).

To set the function of the calibration data press

is shown at the bottom of the display. Set

LAMBDCALtoOFF

calibration data to reposition the lter, and set

repeatedly until

4

Syst

to use the

LAMBDCALtoON

LAMBDCAL

to use the

5

calibration data to change the attenuation factor.

As well as the wavelength calibration data measured for and stored in your

instrument in the factory, there is space reserved in memory for a set of your

own user calibration data. (You load this data into the instrument over the

HP-IB. See \User Calibration Commands" in Chapter 8)

Press

4

5

repeatedly until

Syst

OFF

selects the factory-made wavelength calibration data.

USERCAL

is shown at the bottom of the display.

wavelength calibration data.

1-6 Getting Started

ON

selects the user

Using the Attenuator

This chapter describes the use of the HP 8156A as an attenuator. There is an

example given at the end of this chapter.

Setting Up the Hardware

To use the attenuator, you need to set up the hardware as shown in the gure

below.

2

2

Figure 2-1. The Hardware Conguration for the Attenuator

Note

The connector interface you need depends on the connector type you are using

(see \Connector Interfaces and Other Accessories" in Appendix B).

If you have option 121, then the Monitor Output provides a signal for

monitoring the power getting through the attenuator. The signal level is

approximately 5% of the output power level. For the most accurate results,

Before using the instrument, you should make sure that it is

properly warmed up. The instrument is properly warmed up

when it has been switched on for a minimum of 45 minutes.

Failure to do this can cause errors of up to 0.04dB in the

attenuation.

Using the Attenuator 2-1

2

you should measure the coupling ratio, and its wavelength dependence, for the

Monitor Output yourself.

Setting Up the Attenuation

The attenuation can be set in two dierent ways. This section describes how to

set the attenuation by specifying the attenuation factor and an oset (called a

calibration factor).

\Selecting the Through-Power Mode" in Chapter 5 describes how to set the

attenuation by specifying the power that gets through.

Entering the Attenuation Factor

The attenuation factor is shown at the top left of the display

.

Figure 2-2. The Attenuation Factor on the Display

Edit the attenuation factor using the modify keys.

The lter attenuation is changed while you edit the attenuation factor according

to the equation:

Att

lter

(dB)=

Att(dB)0

Cal(dB

) (1)

To edit the attenuation factor,

5

1. press

4

Att

, and

2. edit the factor using the Modify keys (see \Using the Modify Keys" in

Chapter 1).

2-2 Using the Attenuator

Resetting the Attenuation Factor

To reset the attenuation factor, press and hold

4

5

until the value resets (this

Att

takes approximately two seconds). The attenuation factor resets so that the

lter attenuation is zero, that is

2

Att(dB)=Cal(dB

)

Entering a Calibration Factor

The calibration factor is shown at the bottom left of the display

Figure 2-3. The Calibration Factor on the Display

This factor does not aect the lter attenuation. It is used to oset the values

for the attenuation factor.

There are two ways of entering the calibration factor.

by editing, and

by transferring

Editing the Calibration Factor

You would use this, for example, to enter an oset to compensate for the

insertion loss (attenuation) of your hardware setup.

The lter attenuation stays constant while you edit the calibration factor.

This means that the attenuation factor, shown on the display, changes according

to the formula below (from equation (1)):

Att

NEW

(dB)=

Att

lter

(dB)+

Cal

NEW

(dB)=

Att

(dB)0Cal

OLD

OLD

(dB)+

Cal

NEW

(dB)

To edit an external calibration factor,

1. press

4

Cal

5

, and

2. edit the factor using the Modify keys (see \Using the Modify Keys" in

Chapter 1).

Using the Attenuator 2-3

2

Resetting the Calibration Factor.

hold

4

5

until the value resets to zero (this takes approximately two seconds).

Cal

To reset the calibration factor, press and

The calibration factor resets to zero.

Transferring to the Calibration Factor

You can transfer the attenuation factor shown on the display into the calibration

factor, so that the attenuation factor is reset to zero.

You would use this, for example, after you have set the power through the

attenuator at a specic level. When you have reset the attenuation factor, you

can edit it to get a relative attenuation.

The lter attenuation stays constant when you transfer to the calibration factor.

This means that the new calibration factor is calculated from the attenuation

factor and the old calibration factor according to the formula below (from

equation (1)):

Cal

To transfer to the calibration factor, press

(dB)=0Att

NEW

lter

(dB)=

Cal

OLD

4

Disp!Cal

(dB)0Att

5

.

OLD

(dB)

Entering the Wavelength

The attenuation at any point on the lter is wavelength dependent.

This dependence is measured and stored in the instrument, and is used, with

the value for the wavelength entered by the user, to compensate for the

dependence. This is the wavelength calibration data.

Note

There are two ways of using the wavelength calibration data,

to reposition the lter so that the attenuation stays

constant, or

to change the attenuation factor on the display to show the

wavelength dependence.You use this to set the wavelength

for an unknown source (you alter the wavelength until the

displayed attenuation matches the measured attenuation).

There are two sets of wavelength calibration data, one made

in the factory, individually, for your instrument. The user

denes the other.

2-4 Using the Attenuator