Keysight Technologies N77 Series User manual

User’s Guide
Keysight N77xx Series
N7751A 1-Channel Optical Attenuator and Power Meter
N7752A 2-Channel Optical Attenuator and Power Meter
N7761A 1-Channel Optical Attenuator
N7762A 2-Channel Optical Attenuator
N7764A 4-Channel Optical Attenuator
N7766A 2-Channel Multimode Optical Attenuator
N7768A 4-Channel Multimode Optical Attenuator

Notices
©Keysight Technologies, Inc. 2015
No part of this manual may be
reproduced in any form or by any
means (including electronic storage
and retrieval or translation into a
foreign language) without prior
agreement and written consent from
Keysight Technologies, Inc. as
governed by United States and
international copyright laws.
Manual Part Number
N7751-90B01
Edition
Edition 7.0,January 2015
Keysight Technologies,
Deutschland GmbH
Herrenberger Str. 130
71034 Böblingen, Germany
For Assistance and Support
http://www.keysight.com/find/assist
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 modification
or misuse, operation outside of the
environmental specifications for the
product, or improper site preparation
or maintenance. No other warranty is
expressed or implied. Keysight
Technologies specifically disclaims
the implied warranties of
Merchantability and Fitness for a
Particular Purpose.
Warranty
THE MATERIAL CONTAINED IN THIS
DOCUMENT IS PROVIDED “AS IS,”
AND IS SUBJECT TO BEING
CHANGED, WITHOUT NOTICE, IN
FUTURE EDITIONS. FURTHER, TO
THE MAXIMUM EXTENT PERMITTED
BY APPLICABLE LAW, KEYSIGHT
DISCLAIMS ALL WARRANTIES,
EITHER EXPRESS OR IMPLIED, WITH
REGARD TO THIS MANUAL AND ANY
INFORMATION CONTAINED HEREIN,
INCLUDING BUT NOT LIMITED TO
THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE.
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FOR ERRORS OR FOR INCIDENTAL
OR CONSEQUENTIAL DAMAGES IN
CONNECTION WITH THE
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PERFORMANCE OF THIS DOCUMENT
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THE MATERIAL IN THIS DOCUMENT
THAT CONFLICT WITH THESE
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Technology Licenses
The hardware and/or software
described in this document are
furnished under a license and may be
used or copied only in accordance
with the terms of such license.
Restricted Rights Legend
If software is for use in the
performance of a U.S. Government
prime contract or subcontract,
Software is delivered and licensed as
“Commercial computer software” as
defined in DFAR 252.227-7014 (June
1995), or as a “commercial item” as
defined in FAR 2.101(a) or as
“Restricted computer software” as
defined in FAR 52.227-19 (June 1987)
or any equivalent agency regulation
or contract clause. Use, duplication or
disclosure of Software is subject to
Keysight Technologies’ standard
commercial license terms, and non-
DOD Departments and Agencies of
the U.S. Government will receive no
greater than Restricted Rights as
defined in FAR 52.227-19(c)(1-2)
(June 1987). U.S. Government users
will receive no greater than Limited
Rights as defined in FAR 52.227-14
(June 1987) or DFAR 252.227-7015
(b)(2) (November 1995), as applicable
in any technical data.
Safety Notices
A
CAUTION
notice denotes a
hazard. It calls attention to an
operating procedure, practice,
or the like that, if not correctly
performed or adhered to, could
result in damage to the product
or loss of important data. Do not
proceed beyond a
CAUTION
notice until the indicated
conditions are fully understood
and met.
A WARNING notice denotes a
hazard. It calls attention to an
operating procedure, practice,
or the like that, if not correctly
performed or adhered to, could
result in personal injury or
death. Do not proceed beyond a
WARNING notice until the
indicated conditions are fully
understood and met.
CAUTION
WARNING

Contents
1 Getting Started
Overview 9
Keysight N775xA Optical Attenuator and Power Meter and N776xA Optical
Attenuator 10
Initial Inspection 12
Safety Considerations 13
Safety Considerations - Overview 13
Safety Symbols 13
General 14
Operating Environment 15
Line Power Requirements 15
Input/Output Signals 16
Line Power Connectors 16
Instrument Markings 17
AC Line Power Supply Requirements 18
AC Line Power Supply Requirements - Overview 18
Line Power Requirements 18
Line Power Cable 18
Changing the Fuse 20
Operating and Storage Environment 20
Operating and Storage Environment - Overview 20
Temperature 20
Humidity 21
Altitude 21
Pollution Protection 21
Instrument Cooling 21
Contents
Keysight N77xx Series
4

Input and Output Connectors 22
Input and Output Connectors - Overview 22
Front Panels - Optical Attenuators 23
Rear Panel 25
Making Optical Connections 26
Making Optical Connections 26
Electrical Connectors 28
LAN Interface 29
LAN Interface 29
Selecting a LAN Network 29
Private LAN Considerations 30
Security 30
Performance 30
Reliability 31
IP Address Availability 31
Site LAN Considerations 31
Connecting the LAN Cable 31
GPIB Interface 34
GPIB Interface 34
Cables and Adapters 34
Connector 34
GPIB Logic Levels 35
USB Interface 35
Powering Up the Instrument 36
Powering Up the Instrument 36
Front Panel Indicators 36
Connecting to the Instrument 37
Connecting to the Instrument - Overview 37
Connecting over USB 37
Finding the IP Address of an instrument 38
Connecting over LAN 40
Claims and Repackaging 43
Claims and Repackaging 43
Return Shipments to Keysight Technologies 43
Contents
5
Keysight N77xx Series

N77xx Viewer Common User Interface Functions 44
Connecting to an Instrument 44
Viewing Measurements 46
Saving and Recalling Configurations 47
Controlling the Instrument Refresh 48
2 Attenuation
Attenuation 49
Controlling the Optical Attenuator 49
Setting Attenuation 51
Setting the Number of Digits displayed 51
Selecting the Power Units 51
Setting the Attenuation 52
How to Remove Electrical Offsets (Zero) 53
Enabling and Disabling the Output 55
How to Set a Power Level 55
How to Set the Wavelength 56
How to Set the Averaging Time 56
Compensating for Wavelength Dependencies in your test setup 56
Applying an Offset Table 56
3 Specifications and Regulations Compliance
Definition of Terms 59
Literature 71
Technical Specifications - Optical Variable Attenuator and Power Meter 72
Optical Attenuator 72
Optical Power Meter 74
General Characteristics 75
Declarations of Conformity - Optical Multiport Attenuator and Power Meter 76
Regulations Information 77
EMC Canada 77
Acoustic Noise Information Germany 77
Remove all doubt 77
Remove all doubt 77
Keysight E-mail Updates 77
Keysight Direct 78
Keysight Open 78
LXI 78
www.keysight.com 78
Contents
Keysight N77xx Series
6

4 Accessories
Accessories - Overview 79
Instrument and Options - Keysight N7751A, N7752A, N7761A, N7762A,
N7764A, N7766A, N7768A 80
Cables 81
5 Maintenance and Troubleshooting
Maintenance and Troubleshooting - Overview 83
Cleaning Instructions 83
Cleaning Instructions 83
Cleaning Instructions for this Instrument 84
Safety Precautions 84
Why is it important to clean optical devices? 84
What do I need for proper cleaning? 85
Preserving Connectors 90
Cleaning Instrument Housings 90
Which Cleaning Procedure should I use? 91
How to clean connectors 91
How to clean connector adapters 93
How to clean bare fiber adapters 93
How to clean optical glass plates 94
Additional Cleaning Information 94
Other Cleaning Hints 95
Firmware Upgrades 95
Error Messages 96
SYST:ERR? 96
Data Sanitation 96
Memory Inventory 96
Clearing User Data 96
Index
Contents
7
Keysight N77xx Series

Contents
Keysight N77xx Series
8

1
Getting Started
Overview
This chapter helps you start using your N77-Series instrument.
•“Keysight N775xA Optical Attenuator and Power Meter and
N776xA Optical Attenuator” on page 10
•“Initial Inspection” on page 12
•“Safety Considerations - Overview” on page 13
•“AC Line Power Supply Requirements - Overview ” on page 18
•“Operating and Storage Environment - Overview ” on page 20
•“Input and Output Connectors - Overview” on page 22
•“Making Optical Connections” on page 26
•“Electrical Connectors” on page 29
•“LAN Interface” on page 29
•“GPIB Interface” on page 34
•“USB Interface” on page 35
•“Powering Up the Instrument” on page 36
•“Connecting to the Instrument - Overview” on page 37
•“Claims and Repackaging” on page 43
Keysight N77xx
Series User's Guide

Keysight N775xA Optical Attenuator and Power Meter and N776xA
Optical Attenuator
The Keysight N775xA and N776xA are compact multichannel
attenuators and power meters. They are a new class of remote-
controlled fiber optic instruments. All attenuators feature power
control functionality to set the output power level of the attenuator.
The Keysight N7751A and Keysight N7752A are optical attenuators for
single mode fiber with one and two single-mode fiber attenuator
channels respectively and two extra optical power meter channels, for
convenient power measurements and setup calibration. The Keysight
N7761A, Keysight N7762A and Keysight N7764A are single-mode fiber
optical attenuators for single mode fiber, with one, two and four
attenuator channels respectively.
All N775xA and N776xA attenuators address productivity challenges by
increasing throughput and operational efficiency.
1 Getting Started
10
Keysight N77xx Series

The Keysight N7766A and the Keysight N7768A are optical attenuators
for multimode fibers with two or four attenuator channels repectively.
Both multimode attenuators are available with 50 micro-meter, 62.5
micro-meter, or 80 micro-meter-core multimode fibre.
The N7766A and N7768A are 2 and 4 channel multimode fiber
attenuators that are optimized for quick power setting and preservation
of the input modal power distribution.
The attenuators are designed to attenuate and control the power of light
in optical fibers. They allow you to accurately and repeatably set the
attenuation factor or power level manually using the Viewer software,
or using the programming interface.
The attenuators include power control functionality that allow you to
set the output power level of the attenuator. When power control mode
is enabled, the module automatically corrects for power changes at the
input so that the output power level you set is maintained.
Figure 1 Optical Attenuators with Power Control
The one rack unit (1U half-rack high) instrument can be operated alone
or with other units, controlled over LAN, USB, or GPIB.
These attenuators and power meters are fully compatible with setups
and programs developed using the Keysight 8157x modular
attenuators and basic 8163x optical power meter commands, not
including logging functionality.
Modal Fidelity for Multimode Fiber Systems
Signals in multimode fibers are distributed over a range of mode groups
that can have different loss and delay in a link. For dependable
multimode transceiver testing, the instrument used to set the power
level should not change this modal distribution. The bulk-optic filter and
collimated beam path of Keysight multimode attenuators are designed
to assure homogeneous attenuation of all input modes.
Getting Started 1
Keysight N77xx Series
11

Initial Inspection
Inspect the shipping container for damage. If there is damage to the
container or cushioning, keep them until you have checked the contents
of the shipment for completeness and verified the instrument both
mechanically and electrically. The Function Tests give a procedure for
checking the operation of the instrument. If the contents are incomplete,
mechanical damage or defect is apparent, or if an instrument does not
pass the operator’s checks, notify the nearest Keysight Technologies
Sales/Service Office.
N O T E To avoid hazardous electrical shock, do not perform electrical tests when there are
signs of shipping damage to any portion of the outer enclosure (covers, panels, and
so on).
1 Getting Started
12
Keysight N77xx Series

Safety Considerations
Safety Considerations - Overview
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 specific warnings elsewhere in
this manual violates safety standards of design, manufacture, and
intended use of the instrument. Keysight Technologies Inc. assumes no
liability for the customer’s failure to comply with these requirements.
This product has been designed and tested in accordance with IEC
Publication 61010-1, Safety Requirements for Electrical Equipment for
Measurement, Control and Laboratory, and has been supplied in a safe
condition. The instruction documentation contains information and
warnings that must be followed by the user to ensure safe operation and
to maintain the product in a safe condition.
Safety Symbols
CAUTION The caution sign denotes a hazard. It calls attention to a procedure which, if not
correctly performed or adhered to, could result in damage to or destruction of the
product. Do not proceed beyond a caution sign until the indicated conditions are
fully understood and met.
WARNING The warning sign denotes a hazard. It calls attention to a procedure 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.
Getting Started 1
Keysight N77xx Series
13

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.
General
This is a Safety Class 1 instrument (provided with a protective earth
terminal) and has been manufactured and tested according to
international safety standards.
Before operation, you should review the instrument and manual for
safety markings and instructions. You must follow these to ensure safe
operation and to maintain the instrument in safe condition.
Some circuits are powered whenever the instrument is connected to the
AC power source. To disconnect from the line power, disconnect the
power cord either at the rear power inlet or at the AC line power source
(receptacle). One of these must always be accessible. If the instrument
is in a cabinet, it must be disconnected from the line power by the
system’s line power switch.
WARNING To avoid hazardous electrical shock, do not perform electrical tests when there
are signs of shipping damage to any portion of the outer enclosure (covers,
panels, and so on).
1 Getting Started
14
Keysight N77xx Series

Operating Environment
WARNING The instrument is not designed for outdoor use. To prevent potential fire or shock
hazard, do not expose the instrument to rain or other excessive moisture.
Line Power Requirements
CAUTION The instrument complies with installation category II and can operate from the
single-phase AC power source that supplies between 100 V and 240 V at a frequency
of 50/60 Hz. The maximum voltage fluctuation is 10% of the nominal supply
voltage. The maximum power consumption is 60 VA with all options installed.
Getting Started 1
Keysight N77xx Series
15

Input/Output Signals
CAUTION There is one input BNC connector: Trigger In. This is a TTL input. A maximum of 5
V can be applied as an external voltage to this input connector.
There is one output BNC connector: Trigger Out. This is a TTL output. Do not apply
an external voltage to this connector.
Line Power Connectors
In accordance with international safety standards, the 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. Please refer to “Accessories - Overview” on page 79“ for
the part numbers of available power cables.
1 Getting Started
16
Keysight N77xx Series

WARNING To avoid the possibility of injury or death, you must observe the following
precautions before switching on the instrument.
•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.
•Do not interrupt the protective earth connection intentionally.
•Do not remove protective covers. Operating personnel must not remove
instrument covers. Component replacement and internal adjustments must
be made only by qualified service personnel.
•Instruments that appear damaged or defective should be made inoperative
and secured against unintended operation until they can be repaired by
qualified service personnel.
•Defective, damaged, or malfunctioning laser sources must be returned to an
Keysight Technologies Service Center.
Do not operate the instrument in the presence of flammable gases or fumes.
Operation of any electrical instrument in such an environment constitutes a
definite safety hazard.
Instrument Markings
The instruction manual symbol. The
product is marked with this warning
symbol when it is necessary for the user
to refer to the instructions in the manual.
The CE mark is the conformity marking
of the European Community
The CSA mark is the certification mark
of the Canadian Standards Association.
or The C-Tick or RCM mark is the
certification mark of the Australian
Communications Authority.
The KC mark is the Korean certification
mark.
Getting Started 1
Keysight N77xx Series
17

The recycling symbol indicates the
general ease with which the instrument
can be recycled.
AC Line Power Supply Requirements
AC Line Power Supply Requirements - Overview
This secton provides information on:
•Line Power Requirements
•Line Power Cable
•Changing the Fuse
Line Power Requirements
The instrument complies with installation category II and can operate
from the single-phase AC power source that supplies between 100 V and
240 V at a frequency of 50/60 Hz. The maximum voltage fluctuation is
10% of the nominal supply voltage. The maximum power consumption
is 60 VA with all options installed.
Line Power Cable
In accordance with international safety standards, the instrument has
a three-wire power cable. When connected to an appropriate AC power
receptacle, this cable earths the instrument cabinet. For the part
number of the power cable for your country and instrument see the
“Accessories - Overview” on page 79.
Do not dispose in domestic household
waste. To return unwanted products,
contact your local Keysight office, or
see http://about.keysight.com/en/
companyinfo/environment/
takeback.shtml for more information.
1 Getting Started
18
Keysight N77xx Series

CAUTION Please note that the switch on the front panel of the instrument does not stop the
flow of power to the instrument.
If you need to turn off the power, unplug the instrument at the mains or remove the
power cable connector from the appliance coupler at the rear of the instrument. For
this reason, the power cable connection should be easily accessible - allowing you
to turn off the power quickly. If the instrument is in a cabinet, it must be disconnected
from the line power by the system’s line power switch.
The power switch allows you to switch between stand-by mode and
power-on mode.
Figure 2 Power Switch
When the instrument is in stand-by mode, the Pwr LED is orange. When
the instrument is powered-on, the Pwr LED is green.
WARNING To avoid the possibility of injury or death, you must observe the following
precautions before switching on the instrument.
•Insert the power cable plug only into a socket outlet provided with a protective
earth contact. Do not negate this protective action by using an extension cord
without a protective conductor.
•Do not interrupt the protective earth connection intentionally.
The AC power requirements are summarized on the rear panel of the
instrument.
Getting Started 1
Keysight N77xx Series
19

Figure 3 AC Power Requirement Markings
Changing the Fuse
CAUTION There is no user replaceable fuse for the instrument. Changing the fuse should be
carried out only by Keysight Technologies service personnel. If you need to get
the fuse replaced refer to your nearest Keysight Technologies Sales/Service
Office.
Operating and Storage Environment
Operating and Storage Environment - Overview
The following summarizes the operating environment ranges. In order
for the instrument to meet specifications, the operating environment
must be within these limits.
WARNING The instrument is not designed for outdoor use. To prevent potential fire or shock
hazard, do not expose the instrument to rain or other excessive moisture.
Temperature
The instrument should be protected from temperature extremes and
changes in temperature that may cause condensation within it.
The operating temperature is from 5°C to +40°C.
The storage temperature is from -40°C to +70°C.
1 Getting Started
20
Keysight N77xx Series