Agilent Technologies 83491 User manual

Agilent 83491/2/3/4A
Clock Recovery Modules
User’s Guide
book.book Page i Monday, January 7, 2002 2:12 PM

ii
© Copyright 2000-2002
Agilent Technologies
All Rights Reserved. Repro-
duction, adaptation, or trans-
lation without prior written
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Agilent Part No. 5962-5960
Printed in USA
January 2002
Agilent Technologies
Lightwave Division
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Notice.
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Warranty.
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instrument product is war-
ranted against defects in
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rants that its software and
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lent Technologies for use with
an instrument will execute its
programming instructions
when properly installed on
that instrument. Agilent Tech-
nologies does not warrant that
the operation of the instru-
ment, or software, or firmware
will be uninterrupted or error-
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Limitation of Warranty.
The foregoing warranty shall
not apply to defects resulting
from improper or inadequate
maintenance by Buyer, Buyer-
supplied software or interfac-
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Safety Symbols.
CAUTION
The caution sign denotes a
hazard. It calls attention to a
procedure which, if not cor-
rectly performed or adhered
to, could result in damage to
or destruction of the product.
Do not proceed beyond a cau-
tion sign until the indicated
conditions are fully under-
stood and met.
WARNING
The warning sign denotes a
hazard. It calls attention to a
procedure which, if not cor-
rectly 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 instruction man-
ual symbol. The prod-
uct is marked with this
warning symbol when
it is necessary for the
user to refer to the
instructions in the
manual.
The laser radiation
symbol. This warning
symbol is marked on
products which have a
laser output.
The AC symbol is used
to indicate the
required nature of the
line module input
power.
|The ON symbolsare
used to mark the posi-
tions of the instrument
power line switch.
 The OFF symbols
are used to mark the
positions of the instru-
ment power line
switch.
The CE mark is a reg-
istered trademark of
the European Commu-
nity.
The CSA mark is a reg-
istered trademark of
the Canadian Stan-
dards Association.
The C-Tick mark is a
registered trademark
of the Australian Spec-
trum Management
Agency.
This text denotes the
instrument is an
Industrial Scientific
and Medical Group 1
Class A product.
Typographical Conven-
tions.
The following conventions are
used in this book:
Key type for keys or text
located on the keyboard or
instrument.
Softkey type for key names that
are displayed on the instru-
ment’s screen.
Display type for words or
characters displayed on the
computer’s screen or instru-
ment’s display.
User type for words or charac-
ters that you type or enter.
Emphasis type for words or
characters that emphasize
some point or that are used as
place holders for text that you
type.
ISM1-A
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iii
General Safety Considerations
General Safety Considerations
This product has been designed and tested in accordance with the standards
listed on the Manufacturer's Declaration of Conformity, and has been supplied
in a safe condition. The 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.
Agilent 83491/2/3/4A modules work only with Agilent digital communication
analyzer mainframes. Refer to the mainframe documentation to ensure safe
operation.
WARNING Light energy can radiate from the front panel OUTPUT connectors on
Agilent 83492A, 83493A, and 83494A modules. The light emitted from
these connectors is the slightly attenuated light that is input to the
front-panel INPUT connector.
WARNING If this instrument is not used as specified, the protection provided by
the equipment could be impaired. This instrument must be used in a
normal condition (in which all means for protection are intact) only.
WARNING To prevent electrical shock, disconnect the Agilent 83491/2/3/4A from
mains before cleaning. Use a dry cloth or one slightly dampened with
water to clean the external case parts. Do not attempt to clean
internally.
WARNING No operator serviceable parts inside. Refer servicing to qualified
personnel. To prevent electrical shock, do not remove covers.
CAUTION This product is designed for use in Installation Category II and Pollution
Degree 2 per IEC 1010 and 664 respectively.
CAUTION Electrostaticdischarge (ESD)onornearinputconnectorscandamagecircuits
inside the instrument. Repair of damage due to misuse is not covered under
warranty. Before connecting any cable to the electrical input, momentarily
short the center and outer conductors of the cable together. Personnel should
be properly grounded, and should touch the frame of the instrument before
touching any connector.
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iv
General Safety Considerations
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Contents
Contents-1
General Safety Considerations iii
1 Installation
Installation 1-2
2Operation
Agilent 83491/2/3/4A Modules—At a Glance 2-2
Front-Panel Features 2-5
Block Diagrams 2-8
To Display a Signal 2-11
To Compensate for Module Insertion Loss 2-12
Using Probes with an Agilent 83491A 2-13
3 Specifications and Regulatory Information
Agilent 83491A Specifications 3-3
Agilent 83492A Specifications 3-4
Agilent 83493A Specifications 3-6
Agilent 83494A Specifications 3-7
Agilent 83491/2/3/4A Operating Specifications 3-9
Regulatory Information 3-10
Declaration of Conformity 3-11
4 Reference
Front-Panel Optical Adapters 4-2
In Case of Difficulty 4-3
Error Messages 4-5
Electrostatic Discharge Information 4-8
Cleaning Connections for Accurate Measurements 4-10
Returning the Instrument for Service 4-20
Agilent Technologies Service Offices 4-23
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1
To install the module 1-3
To connect cables to an Agilent 83492A 1-7
Installation
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1-2
Installation
Installation
Installation
Agilent 83491/2/3/4A modules require that firmware revision A.06.25 or later
be installed in the Agilent 83480A. If you wish to install the module in an
Agilent 54750A digitizing oscilloscope, you must first install the
Agilent 83480K communications firmware upgrade kit.
NOTE The front panel of Agilent 83494A clock recovery modules have an auxiliary clock
outputthatprovidestherecoveredclocksignal,referto “Auxiliaryoutputs”onpage2-6.
To use this output with the 9.953 and 10.664 Gb/s (Option 106) data rates, the digital
communications analyzer mainframe with the 12 GHz (Divided Trigger) option is
required.
To check the Agilent 83480A’s firmware revision code
1Press the Utility key and then the System config softkey.
2The firmware revision number is listed under the Frame section of the display.
CAUTION Fiber-optic connectors are easily damaged when connected to dirty or
damaged cables and accessories. The Agilent 83492A, 83493A, and 83494A
front-panel input connectors are no exception. When you use improper
cleaning and handling techniques, you risk expensive instrument repairs,
damaged cables, and compromised measurements. Before you connect any
fiber-optic cable to an Agilent 83492A, 83493A, or 83494A module, refer to
“Cleaning Connections for Accurate Measurements”on page 4-10.
CAUTION The circuits on electrical inputs and outputs can be damaged by electrostatic
discharge (ESD). Therefore, avoid applying static discharges to any front or
rear-panel electrical connector. Before connecting any coaxial cable to a front-
panel connector, momentarily short the center and outer conductors of the
cable together. Avoid touching the front-panel connectors without first
touching the frame of the instrument. Be sure that the instrument is properly
earth-grounded to prevent buildup of static charge. Refer to “Electrostatic
Discharge Information”on page 4-8.
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1-3
Installation
Installation
To install the module
1Verify that all system components ordered have arrived by comparing the
shipping forms to the original purchase order. Inspect all shipping containers.
The shipment includes:
 An Agilent 83491/2/3/4A Clock Recovery Module
 Fiber-optic adapter cable (Agilent 83492/3/4A module only)
 Two RF adapter cables (Agilent 83491A module only)
 Agilent 83491/2/3/4A User’s Guide (this book)
If your shipment is damaged or incomplete, save the packing materials and
notify both the shipping carrier and the nearest Agilent Technologies service
office. Agilent Technologies will arrange for repair or replacement of damaged
or incomplete shipments without waiting for a settlement from the transporta-
tion company. Notify the Agilent Technologies customer engineer of any prob-
lems.
1Make sure that the serial number listed on the module’s rear-panel label
matches the serial number listed on the shipping document.
Figure 1-1. Serial nu ber label
2Install the Agilent 83491/2/3/4A module into the Agilent 83480A mainframe’s
left slot. Finger-tighten the knurled screw on the front panel of the plug-in
module to ensure that the module is securely seated in the mainframe.
Note
Installing the module into the left slot ensures that the supplied adapter cable will fit.
See igure 1-2.
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1-4
Installation
Installation
Figure 1-2. Position of odules in the ainfra e
3Clean all optical interfaces as described in “Cleaning Connections for Accurate
Measurements”on page 4-10,before making measurements.
4Perform the following steps if you’re installing an Agilent 83492/3/4A module:
aUnscrew and remove the fiber-optic adapter that is located on the optical
module’s front-panel optical input connector.
bConnect the adapter that was removed in the previous step onto the
Agilent 83492/3/4A module’s front-panel Input connector.
On Agilent 83492A module’s, the input connector used depends on the
wavelength of the input signal. Refer to “To connect cables to an
Agilent 83492A”on page 1-7.
5Connect the supplied adapter cable as shown in Figure 1-3.
WARNING Light energy can radiate from the front panel OUTPUT connectors on
Agilent 83492A, 83493A, and 83494A modules. The light emitted from
these connectors is the slightly attenuated light that is input to the
front-panel INPUT connector.
6Turn on the Agilent 83480A, and connect a modulated signal to the
Agilent 83491/2/3/4A module’s Input connector.
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1-5
Installation
Installation
Figure 1-3. The adapter cable
CAUTION Agilent 83491A Modules: Maximum safe signal input level is ±5V. The input
circuits can also be damaged by electrostatic discharge (ESD). Before
connecting any coaxial cable to the connectors, momentarily short the center
and outer conductors of the cable together. Avoid touching the front-panel
input connectors without first touching the frame of the instrument. Be sure
that the instrument is properly earth-grounded to prevent buildup of static
charge.
CAUTION Agilent 83492/3/4A Modules: Maximum safe signal input level is +3 dBm.
7On the Agilent 83480A, press the Trigger key and then the Source softkey. Then,
select trigger 2 (the Agilent 83491/2/3/4A module) for the trigger source.
8On the Agilent 83491/2/3/4A module, repeatedly press the SELECT key until a
front-panel light indicates the data rate of the signal. See Figure 1-4 on
page 1-6.
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1-6
Installation
Installation
Figure 1-4. Front-panel lights
9Confirm that the Unlocked light is off. If using the Agilent 83494A, confirm that the
Trigger Loss light is off.
10 Observe the Clock and Data outputs on an oscilloscope. Waveforms should be
present. The instrument is now ready for you to begin making measurements.
Green and red data-rate lights
The data-rate indicator lights on the Agilent 83491/2/3A and Agilent 83494A Option 106
change color between red and green to show which data rate is selected. A red light
does not indicate a problem. A red light shows that the adjacent red data rate label is
selected. A green light shows that the adjacent green data rate label is selected.
Repeatedly pressing the SELECT key cycles through the selections in one color before
switching to the opposite color. On Agilent 83491A modules for example, the first selec-
tion cycle shows 155 Mb/s selected. The second selection cycle shows 1062 Mb/s
selected.
Agilent 83494A modules use only the green data-rate indicator light to show which data
rate is selected. Repeatedly pressing the SELECT key cycles through the available data
rates, as well as the Trigger On Data bypass mode.
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1-7
Installation
Installation
To connect cables to an Agilent 83492A
On Agilent 83492A modules, the front-panel fiber-optic connectors reverse
input and output roles depending on the wavelength of the signal. Signals in
the 750 nm to 860 nm wavelength range are input to the left connector and
output from the right connector. Signals in the 1000 nm to 1600 nm wave-
length range are input to the right connector and output from the left connec-
tor.
Figure 1-5. Input and output connections versus wavelength
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2
Agilent 83491/2/3/4A Modules—At a Glance 2-2
Front-Panel Features 2-5
Block Diagrams 2-8
To Display a Signal 2-11
To Compensate for Module Insertion Loss 2-12
Using Probes with an Agilent 83491A 2-13
To compensate for a passive probe 2-14
To compensate an Agilent 54701A active probe 2-14
To compensate for other devices 2-15
Operation
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2-2
Operation
Agilent 83491/2/3/4A Modules—At a Glance
Agilent 83491/2/3/4A Modules—At a Glance
The Agilent 83491/2/3/4A are designed to operate in an Agilent 83480A and an
Agilent 86100A digital communications analyzer. These modules recover clock
and data information at standard telecom and datacom rates. The resulting
trigger signal is made available to the Agilent 83480A mainframe via a connec-
tor located on the module’s rear-panel. An external front-panel cable passes
the data signal, with some insertion loss, to the receiver module.
Table 2-1. Module Features
Agilent Module Input Connector Selectable Rates (Mb/s)
83491A 50Ω electrical 155, 622, 1060, 1250, 2120, 2488, 2500
83492A Multimode fiber (62.5/125 µm) 155, 622, 1060, 1250, 2120, 2488, 2500
83493A Single-mode fiber (9/125 µm) 155, 622, 1250, 2488, 2500
83494A Single-mode fiber (9/125 µm) 155, 622, 2488, 9953
83494A Option 106 Single-mode fiber (9/125 µm) 155, 622, 2488, 2666, 10664
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2-3
Operation
Agilent 83491/2/3/4A Modules—At a Glance
Figure 2-1. An Agilent 83493A installed in an Agilent 83480A ainfra e
WARNING Light energy can radiate from the front panel OUTPUT connectors on
Agilent 83492A, 83493A, and 83494A modules. The light emitted from
these connectors is the slightly attenuated light that is input to the
front-panel INPUT connector.
Use with Agilent 71603B or 71612B Error Performance Analyzers
The front-panel Data and Clock outputs provide electrical recovered clock and
regenerated data signals for simultaneous testing with other instruments,
such as the Agilent 71603B or 71612B error performance analyzers.
Multimode module and single-mode reference receivers
Agilent Technologies does not recommend using the Agilent 83492A multi-
mode module with single-mode reference receivers such as the
Agilent 83481A, 83482A, or 83485A,B modules. Connecting multimode to sin-
gle-mode fibers causes large reflections and insertion loss because of the
reduction of the optical fiber’s core from 62.5 µm to 9 µm.
Single-mode module and multimode reference receivers
It is acceptable to use an Agilent 83493A or an 83494A single-mode module
with a multimode reference receiver such as the Agilent 83486A module. This
is true provided that single-mode fiber is connected to the Agilent 83493A or
83494A module’s front-panel INPUT connector.
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2-4
Operation
Agilent 83491/2/3/4A Modules—At a Glance
What you won’t find on these odules....
Unlike other modules designed to be used with the Agilent 83480A digital communica-
tions analyzer, the Agilent 83491/2/3/4A modules do not include Channel keys or
menus. Also, there are no GPIB programming commands for these modules. However,
GPIB programming commands are available for the Agilent 86100A digital commumica-
tions analyzer.
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2-5
Operation
Front-Panel Features
Front-Panel Features
Figure 2-2. Agilent 83491/2/3/4A front panels
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2-6
Operation
Front-Panel Features
SELECT key Pressing this key changes the modulation rate of the input signal. The recov-
ered and retimed clock trigger is sent to the mainframe. The Trigger On Data
selection is a bypass mode where the data stream directly triggers the main-
frame. Refer to “Block Diagrams”on page 2-8 to view a schematic of the nor-
mal and bypass paths.
UNLOCKED
indicator
83491/2/3A
This light shows when clock recovery cannot be established on the signal. If a
clock rate is selected, the trigger output to the mainframe is disabled to pre-
vent free-run triggering. However in bypass mode (Trigger On Data selected),
triggering is not disabled. When the UNLOCKED light is on, you can establish a
trigger on the data input to the reference receiver.
Trigger Loss
indicator
83494A
This light shows when clock recovery cannot be established on the signal. If a
clock rate is selected, the trigger output to the mainframe is disabled to pre-
vent free-run triggering. However in bypass mode (Trigger On Data selected),
triggering is not disabled. When the Trigger Loss light is on, you can establish a
trigger on the data input to the reference receiver.
Auxiliary outputs DATA connector: This connector provides a fully regenerated version of the
input signal. It is intended for monitoring purposes only and not for rigorous
eye mask compliance testing. The frequency response does not conform to the
requirements for eye mask testing as described in ITU-T G.957 and Bellcore
GR-253-CORE. On Agilent 83492A and 83493A modules, this port is ampli-
tude stabilized for input signals greater than approximately –23 dBm. On
Agilent 83494A modules, this port is amplitude stabilized for input signals
greater than approximately –10 dBm.
Green and red data-rate lights
The data-rate indicator lights on the Agilent 83491/2/3A and Agilent 83494A Option 106
change color between red and green to show which data rate is selected. A red light
does not indicate a problem. A red light shows that the adjacent red data rate label is
selected. A green light shows that the adjacent green data rate label is selected.
Repeatedly pressing the SELECT key cycles through the selections in one color before
switching to the opposite color. On Agilent 83491A modules for example, the first selec-
tion cycle shows 155 Mb/s selected. The second selection cycle shows 1062 Mb/s
selected.
Agilent 83494A modules use only the green data-rate indicator light to show which data
rate is selected. Repeatedly pressing the SELECT key cycles through the available data
rates, as well as the Trigger On Data bypass mode.
book.book Page 6 Monday, January 7, 2002 2:12 PM