Tektronix OI2125 Instruction Manual Instruction Manual
Instruction Manual
OI2125 O/E Receiver
071-1053-00
Warning
The servicing instructions are for use by qualified
personnel only. To avoid personal injury, do not
perform any servicing unless you are qualified to
do so. Refer to all safety summaries prior to
performing service.
www.tektronix.com
Copyright © T ektronix, Inc. All rights reserved.
T ektronix 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.
T ektronix, Inc., P.O. Box 500, Beaverton, OR 97077
TEKTRONIX and TEK are registered trademarks of T ektronix, Inc.
WARRANTY
T ektronix warrants that the products that it manufactures and sells will be free from defects in materials and workmanship
for a period of one (1) year from the date of purchase from an authorized T ektronix distributor. If any such product proves
defective during this warranty period, T ektronix, 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. Batteries are excluded from this
warranty.
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 T ektronix, shipping charges prepaid, and
with a copy of customer proof of purchase. T ektronix shall pay for the return of the product to Customer if the shipment is
to a location within the country in which the T ektronix 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. T ektronix shall not be obligated to furnish service under this warranty a) to repair damage resulting
from attempts by personnel other than T ektronix 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-T ektronix 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 WITH RESPECT TO THE LISTED PRODUCTS 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 CUST OMER 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.
Table of Contents
General Safety Summary v. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contacting T ektronix viii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Getting Started 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Options 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standard Accessories 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Optional Accessories 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Functional Check 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Basics 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Handling 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting Signals 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front Panel Description 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clock Recovery Modules 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Panel Connections and Controls 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using the Rear-Panel Remote Interface 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Theory of Operation 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
O/E Receiver 32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clock Recovery Modules 33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Performance Verification 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Prerequisites 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment Required 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Photodetector Optical Input 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Data Output 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Eye Pattern T est Matrix 45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clock Recovery Module T ests 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OI2125 O/E Receiver T est Record 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Clock Recovery Module T est Records 57. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance 59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Cleaning 59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Care 59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exterior Cleaning 59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection 60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning Optical Connectors 60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Repackaging Instructions 62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replaceable Parts 63. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Glossary 67. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Index 73. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OI2125 O/E Receiver Instruction Manual
i
Table of Contents
List of Figures
Figure 1: OI2125 Optical-to-Electrical Receiver 1. . . . . . . . . . . . . . . . .
Figure 2: Functional test setup 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 3: Oscilloscope display of an eye pattern 7. . . . . . . . . . . . . . . . .
Figure 4: Connecting a fiber optic cable 11. . . . . . . . . . . . . . . . . . . . . . . .
Figure 5: OI2125 front panel 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 6: Clock Recovery Modules for the receiver 14. . . . . . . . . . . . . . .
Figure 7: Installing a Clock Recovery Module 16. . . . . . . . . . . . . . . . . . .
Figure 8: Releasing the module with the latch 17. . . . . . . . . . . . . . . . . . .
Figure 9: OI1125 rear panel 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 10: Rear Remote Interface connector pinout 19. . . . . . . . . . . . . .
Figure 11: OI2125 Output Voltage versus Input Optical Power 25. . . . .
Figure 12: O/E Receiver interconnect diagram 31. . . . . . . . . . . . . . . . . .
Figure 13: Setup for the LOS threshold test 38. . . . . . . . . . . . . . . . . . . . .
Figure 14: Setup for the bandwidth test 41. . . . . . . . . . . . . . . . . . . . . . . .
Figure 15: Proper positioning of the impulse
for optimum curve download 44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 16: Setup for the eye pattern test matrix 46. . . . . . . . . . . . . . . . .
Figure 17: Measurements taken from the eye pattern 49. . . . . . . . . . . . .
Figure 18: OM1420 Clock Recovery Module test setup 51. . . . . . . . . . .
Figure 19: RMS Jitter measurement 53. . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 20: Cleaning an optical connector 61. . . . . . . . . . . . . . . . . . . . . . .
Figure 21: Standard accessories 63. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Figure 22: Optional power cords 65. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ii
OI2125 O/E Receiver Instruction Manual
List of Tables
Table of Contents
Table 1: Power cord options 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 2: Service options 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 3: Receiver standard accessories 3. . . . . . . . . . . . . . . . . . . . . . . .
Table 4: Clock Recovery Module standard accessories 4. . . . . . . . . . .
Table 5: Optional accessories 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 6: Remote Port signals 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 7: OM1420 Module data rate select and status logic 20. . . . . . . .
Table 8: Clock recovery module type select logic 21. . . . . . . . . . . . . . . .
Table 9: OI2125 Receiver specifications 23. . . . . . . . . . . . . . . . . . . . . . . .
Table 10: OM1420 Clock Recovery Module specifications 24. . . . . . . .
Table 11: Environmental characteristics 26. . . . . . . . . . . . . . . . . . . . . . .
Table 12: Certifications and compliances 27. . . . . . . . . . . . . . . . . . . . . . .
Table 13: Safety characteristics 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 14: OI2125 Receiver PV checks 35. . . . . . . . . . . . . . . . . . . . . . . . .
Table 15: Clock Recovery Module PV checks 35. . . . . . . . . . . . . . . . . . .
Table 16: Test equipment 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 17: OI2125 Receiver test record 55. . . . . . . . . . . . . . . . . . . . . . . . .
Table 18: BERT input @2.48832 Gb/s bit rate 55. . . . . . . . . . . . . . . . . .
Table 19: BERT input @9.95328 Gb/s bit rate 55. . . . . . . . . . . . . . . . . .
Table 20: BERT input @12.50000 Gb/s bit rate 56. . . . . . . . . . . . . . . . .
Table 21: OM1420 test record 57. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table 22: OM1420 clock output data 57. . . . . . . . . . . . . . . . . . . . . . . . . .
Table 23: Inspection check list 60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OI2125 O/E Receiver Instruction Manual
iii
Table of Contents
iv
OI2125 O/E Receiver Instruction Manual
General Safety Summary
Review the following safety precautions to avoid injury and prevent damage to
this product or any products connected to it. To avoid potential hazards, use this
product only as specified.
Only qualified personnel should perform service procedures.
While using this product, you may need to access other parts of the system. Read
the General Safety Summary in other system manuals for warnings and cautions
related to operating the system.
To Avoid Fire or
Personal Injury
Use Proper Power Cord. Use only the power cord specified for this product and
certified for the country of use.
Ground the Product. This product is grounded through the grounding conductor
of the power cord. To avoid electric shock, the grounding conductor must be
connected to earth ground. Before making connections to the input or output
terminals of the product, ensure that the product is properly grounded.
Observe All Terminal Ratings. To avoid fire or shock hazard, observe all ratings
and markings on the product. Consult the product manual for further ratings
information before making connections to the product.
Do Not Operate Without Covers. Do not operate this product with covers or panels
removed.
Use Proper Fuse. Use only the fuse type and rating specified for this product.
Wear Eye Protection. Wear eye protection if exposure to high-intensity rays or
laser radiation exists.
Do Not Operate With Suspected Failures. If you suspect there is damage to this
product, have it inspected by qualified service personnel.
Do Not Operate in Wet/Damp Conditions.
Do Not Operate in an Explosive Atmosphere.
Keep Product Surfaces Clean and Dry .
Provide Proper Ventilation. Refer to the manual’s installation instructions for
details on installing the product so it has proper ventilation.
OI2125 O/E Receiver Instruction Manual
v
General Safety Summary
Symbols and Terms
T erms in this Manual. These terms may appear in this manual:
WARNING. Warning statements identify conditions or practices that could result
in injury or loss of life.
CAUTION. Caution statements identify conditions or practices that could result in
damage to this product or other property.
T erms on the Product. These terms may appear on the product:
DANGER indicates an injury hazard immediately accessible as you read the
marking.
WARNING indicates an injury hazard not immediately accessible as you read the
marking.
CAUTION indicates a hazard to property including the product.
Symbols on the Product. The following symbols may appear on the product:
CAUTION
Refer to Manual
Protective Ground
(Earth) Terminal
Avoid Exposure- Laser Radiation
is Emitted from this Aperture
vi
OI2125 O/E Receiver Instruction Manual
Preface
This is the instruction manual for the OI2125 O/E Receiver. This manual
provides user information and performance verification procedures for the
instrument.
This manual also provides specifications and performance verification procedures for the optional Clock Recovery Modules.
OI2125 O/E Receiver Instruction Manual
vii
Preface
Contacting Tektronix
Phone 1-800-833-9200*
Address Tektronix, Inc.
Department or name (if known)
14200 SW Karl Braun Drive
P.O. Box 500
Beaverton, OR 97077
USA
Web site www.tektronix.com
Sales support 1-800-833-9200, select option 1*
Service support 1-800-833-9200, select option 2*
Technical support Email: techsupport@tektronix.com
1-800-833-9200, select option 3*
6:00 a.m. – 5:00 p.m. Pacific time
* This phone number is toll free in North America. After office hours, please leave a
voice mail message.
Outside North America, contact a Tektronix sales office or distributor; see the
Tektronix web site for a list of offices.
viii
OI2125 O/E Receiver Instruction Manual
Getting Started
The OI2125 (see Figure 1) is an optical-to-electrical receiver that converts a
modulated optical input signal to an electrical data output signal at data rates up
to 12.5 Gb/s. Using an amplified high-speed photodetector, the OI2125 O/E
Receiver operates over a wavelength range of 1100 nm to 1650 nm.
You can use the receiver in a test system to convert the optical signal from a
DUT (Device Under Test) to an electrical signal to be measured with an
oscilloscope or used as a part of a BER (Bit Error Rate) test. When you use the
receiver as part of a BER test, the BERT Pattern Generator supplies a data signal
that is converted to a modulated optical signal by an OI1125 E/O Transmitter.
The OI2125 O/E Receiver is used to convert the optical BER test pattern back to
an electrical signal for analysis by the BERT Error Analyzer.
Using the transmitter and receiver combined with a BERT, you can test the bit
error rate of optical signals in SONET/SDH and other optical transmission
systems.
Figure 1: OI2125 Optical-to-Electrical Receiver
The OI2125 O/E Receiver provides the following features:
H Supports standard SONET data rates from OC48 to OC192 and FEC data
rates up to 12.5 Gb/s.
H Optical wavelength range designed to operate in C band (1530 nm to
1565 nm), but is usable over an extended wavelength range of 1100 nm to
1650 nm.
H Optional clock recovery modules provide data rates for OC-192 and
OC-192 FEC.
OI2125 O/E Receiver Instruction Manual
1
Getting Started
Options
The OI2125 O/E Receiver provides a slot for an optional clock recovery module.
Clock recovery modules currently available:
H The OM1420 clock recovery module provides clock recovery at one of two
selectable data rates: OC-192 (9.953280 Gb/s), and OC-192 Forward Error
Correction (10.66423 Gb/s).
The AC power input to the OI2125 O/E Receiver is supplied through a standard
IEC320 AC input connector. The internal power supply in the receiver operates
with AC power from 100 to 240 VAC at either 50 or 60 Hz. The standard power
cord supplied with the OI2125 O/E Receiver is a 120 VAC North American
power cord.
Table 1 lists the power cord options that are available for your OI2125 O/E
Receiver.
T able 1: Power cord options
Option Description
A1 European power cord (240 V, 50 Hz)
A2 UK power cord (240 V , 50 Hz)
A3 Australian power cord (240 V , 50 Hz)
A5 Swiss power cord (240 V , 50 Hz)
AC Chinese power cord
A99 No power cord
Table 2 lists the Tektronix service options. These options are modular, flexible,
and easy to order with your instrument. Designed to support tracking of
calibration to requirements of ISO9000 and to provide for extended repair
coverage, these options help fix your long-term maintenance costs and eliminate
unplanned expenditures.
T able 2: Service options
Option Description
D1 Provides the initial Test Data Report from the factory on delivery.
C3 Provides factory calibration certification on delivery, plus two more years of
calibration coverage. Throughout the coverage period, the instrument will be
calibrated according to its Recommended Calibration Interval.
D3 Provides test data on delivery plus a Test Data Report for every calibration
performed during three years of coverage (requires Option C3).
2
OI2125 O/E Receiver Instruction Manual
Standard Accessories
Getting Started
T able 2: Service options (Cont.)
Option Description
R3 Extends product repair warranty to a total of three years.
C5 Provides factory calibration certification on delivery, plus four more years of
calibration coverage. Throughout the coverage period, the instrument will be
calibrated according to its Recommended Calibration Interval.
D5 Provides test data on delivery plus a Test Data Report for every calibration
performed during five years of coverage (requires Option C5).
R5 Extends product repair warranty to a total of five years.
Tektronix Service Options are available at the time you order your instrument.
Contact your local Tektronix Sales Office for more information.
Table 3 lists the standard accessories that come with the OI2125 O/E Receiver.
T able 3: Receiver standard accessories
Accessory Part number
US power cord 161-0066-00
Slot Cover Module (preinstalled) 119-6690-00
Low-loss SMA cable 015-0561-00
Optical cable, FC/PC-FC/PC, 2 M 174-3922-00
50 W terminator (2 ea, preinstalled) 015-1022-01
FC/PC adapter (preinstalled) 119-5115-00
Optical connector cleaning kit 006-8217-00
Instruction Manual 071-1053-XX
Certificate of Calibration –––
OI2125 O/E Receiver Instruction Manual
3
Getting Started
The Clock Recovery Modules are orderable separately. Table 4 lists the standard
accessories that come with the modules.
T able 4: Clock Recovery Module standard accessories
Accessory Part number OM1420
Flexible SMA jumper cable 174-4699-00
n
Optional Accessories
Low-loss SMA cable 015-0561-00
50 W terminator (preinstalled) 015-1022-01
Certificate of Calibration ––––––––
Instructions 071-1055-XX
n
n (2 ea)
n
Table 5 lists the optional accessories that are recommended for the OI2125 O/E
Receiver.
T able 5: Optional accessories
Item Part number
SMA 2.5 UCI adapter 119-4517-00
DIAMOND 2.5 UCI adapter 119-4556-00
SMA UCI adapter 119-4557-00
DIAMOND 3.5 UCI adapter 119-4558-00
FC/PC adapter 119-5115-00
SC/APC adapter 119-5116-00
DIN/PC 47256 adapter 119-5887-00
ST/APC adapter 119-5888-00
FC/PC 5dB attenuator 131-7368-00
Side-By-Side Instrument Rack Adapter TVGF13
4
OI2125 O/E Receiver Instruction Manual
Installation
Getting Started
To learn how to install, access the front panel, power on, and power off the
OI2125 O/E Receiver, do the following procedures:
Preparation
To properly install and power on the receiver, do the following steps:
1. Be sure the operating environment is within the specifications listed in
Table 11 starting on page 26.
CAUTION. To prevent damage to the receiver, provide proper ventilation. A small
fan is located on the bottom of the chassis. Do not block the cabinet ventilation
holes, or disable the fan. Do not remove the cabinet feet; the feet provide proper
clearance for ventilation.
2. Leave space for cooling. Do this by verifying that the ventilation holes on
the sides, top, and bottom of the cabinet are free of any airflow obstructions.
Leave at least 5.1 cm (2 inches) free on each side.
3. Check that you have the proper electrical connections. The OI2125 O/E
Receiver requires 100 to 240 VAC
4. Connect the proper power cord from the rear-panel power connector (see
Figure 9 on page 18) to the power system.
CAUTION. To prevent damage to your
while the receiver is powered on. Do not apply a voltage outside the Maximum
Nondestructive Input Voltage for the
handling the module and front panel electrical connectors.
"10%, 47 Hz to 63 Hz, and 40 W.
RMS
module, do not install or remove a module
module. Observe static precautions when
5. Verify that the power is off by ensuring the rear-panel rocker power switch is
in the off position.
6. Plug a clock recovery or slot cover module into the receiver: Slowly insert
the module into the slot in the front panel until it meets the connector at the
back of the module slot.
7. Firmly push the module in to seat it in the connector.
8. Once the module is seated, turn the hold-down screw clockwise to lock the
module into place.
If you are not going to use a clock recovery module, install the slot cover module
in the receiver to limit stray EMI emissions and to protect the receiver from
ambient RF noise.
Power on
Power off
OI2125 O/E Receiver Instruction Manual
To power on the receiver, push the rear-panel rocker power switch to toggle it on
(see Figure 9 on page 18).
To power off the receiver, push the rocker power switch to the off position.
5
Getting Started
Functional Check
To perform a functional check of the OI2125 O/E Receiver, you must connect a
setup as shown in Figure 2. This setup creates an optical data source by
combining a pattern generator with an electrical-to-optical transmitter (with an
internal laser source). This optical data source is fed into the optical input of the
receiver, and the converted data output is displayed as an electrical eye pattern on
the oscilloscope. This is the method that is used in the Eye Pattern Test Matrix
on page 45 of the Performance Verification procedures.
The equipment required, besides the receiver and the optical and electrical cables
supplied as standard accessories, is listed below:
H A pattern generator capable of producing data rates from 2.48 Gb/s to
12.50 Gb/s, with output levels at about 1.0 V
p-p
.
H An electrical-to-optical transmitter capable of providing single-mode optical
signals in the 1550 nm band at data rates up to 12.50 Gb/s.
H A 50 W SMA cable to connect the pattern generator divided-clock output as
an oscilloscope trigger signal.
Pattern generator
Clock
/32
Data
OI1125
Laser out
Low-loss SMA cable
Figure 2: Functional test setup
H A 50 W low-loss SMA cable to connect the receiver output to the oscillo-
scope input.
H A 5 dB optical attenuator to limit the input power to the receiver to less than
0 dBm.
CSA8000/TDS8000 w/80E01
PMF fiber
Modulator
Data in
Modulator
out
Laser in
Single mode fiber
Optical in
(FC/PC)
OI2125
Data out
5 dB Optical
attenuator
Low loss SMA cable
Trigger
Direct In
SMA cable
Follow the Displaying an Eye Pattern procedure on the next page to do a
functional check of the OI2125 O/E Receiver. If you are unfamiliar with making
fiber optic connections, refer to Connecting Signals on page 9.
6
OI2125 O/E Receiver Instruction Manual
Getting Started
Displaying an Eye Pattern
To display an eye pattern, do the following:
1. Connect the test setup as shown in Figure 2, and power on the equipment.
2. Set the BERT bit rate to 9.953280 Gb/s.
3. Set the pattern to PRBS-31.
4. Disable the adjustable duty cycle.
5. Set the mark ratio to 1/2.
6. Set the trigger to 1/32 clock.
7. Set the output mode to AC.
8. Turn the data output on and set the data amplitude to 1.0 V
p–p
.
9. Enable the transmitter laser by turning the keyswitch clockwise (to the
unlocked position). The Laser On LED and Laser Output Active LED light.
10. On the oscilloscope, press Autoset and then adjust the horizontal scale to
display an eye pattern (see Figure 3).
The oscilloscope displays an eye pattern as shown in Figure 3. This indicates
that the receiver is functioning correctly—it is converting the modulated input
optical signal to an electrical eye pattern that represents the data stream from the
BERT.
Figure 3: Oscilloscope display of an eye pattern
OI2125 O/E Receiver Instruction Manual
7
Getting Started
8
OI2125 O/E Receiver Instruction Manual
Operating Basics
Handling
This section describes the connectors and controls on the front and rear panels of
the OI2125 O/E Receiver. Figures 5 and 9 illustrate the front and rear panels of
the instrument.
Handle the OI2125 O/E Receiver carefully at all times. The instrument contains
sensitive optical and electrical components that can be damaged by physical
shocks.
WARNING. To prevent eye injury, do not look directly into any optical output
port. Laser light can be harmful to your eyes. Optical signals in the wavelength
range used by the OI2125 O/E Receiver are in the infrared band and are
invisible to the human eye.
CAUTION.To protect the module and instrument inputs, always use a wrist strap
when handling the module and when making electrical signal connections.
Always replace the terminators on the receiver and module when not in use.
Connecting Signals
Electrical Connectors
Optical Connector
The OI2125 O/E Receiver has two types of connectors for inputs and outputs.
The OI2125 O/E Receiver electrical outputs use high-performance SMA
connectors. Never attach a cable if the cable has a worn or damaged connector
because this may damage the OI2125 connector.
Use extra care when attaching or removing a cable from the connectors. Turn
only the nut, not the cable. Use light finger pressure to make this initial
connection. Then tighten the nut lightly with a wrench.
For best repeatability and to prolong the life of both cable and instrument
connectors, use a torque wrench and tighten the connection to the range of 79 to
112 N-cm (7 to 10 lb-in).
If the connectors will receive heavy use, such as in a production environment,
you should install connector-saver adapters on the OI2125 O/E Receiver to make
connections to the device under test.
The optical input connector of the OI2125 O/E Receiver is a Universal-Style
physical contact (PC) type that can couple to optical fibers with a core diameter
of up to 9 mm. An FC/PC adapter is supplied as a standard accessory for use with
the Universal-Style input connector. Alternative optical connector types can be
OI2125 O/E Receiver Instruction Manual
9
Operating Basics
coupled by using the optional accessory adapters. (Refer to Optional Accessories
on page 4.)
If you connect fiber cores larger than 9 mm, the receiver may still couple light,
but the mismatch in core diameter will result in significant optical attenuation.
To attach a fiber optic cable with an FC/PC connector to the FC/PC input
receptacle, refer to Figure 4 on page 11 and do the following:
1. Remove the dust cover from the optical receptacle.
CAUTION. Use care when making optical connections. If you are not using an
optical connection, either on the receiver, cable or associated optical equipment,
always leave the protective dust cover on the connector. The glass surface of the
fiber optic core is easily contaminated by airborne dust particles.
Treat all optical connectors as you would a camera lens or other precision
optical equipment.
2. Clean the connector on the fiber optic cable using the procedure on page 60.
3. Carefully align the keyway on the receptacle with the key on the connector.
4. Tighten the nut lightly with finger pressure only. If you overtighten an
optical connector, you may get inconsistent optical signal performance.
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OI2125 O/E Receiver Instruction Manual
Keyway
Key
Operating Basics
Tighten
FC/PC
Receptacle
FC/PC
connector
Fiber optic cable with
FC/PC connector
Figure 4: Connecting a fiber optic cable
OI2125 O/E Receiver Instruction Manual
11
Operating Basics
Front Panel Description
The front panel is functionally divided into two sections: the O/E receiver
section and the clock recovery module port. Use Figure 5 and the following
descriptions to help you connect and operate the receiver.
Input detected on
LED
Optical
input
Power
on
LED
Figure 5: OI2125 front panel
O/E Receiver
Data out (2)
Remote
enable
switch
Remote
enabled
LED
Clock Recovery
Module
The O/E receiver section is described here.
OPTICAL INPUT. The optical input port is designed to accept modulated optical
signals over a range of digital data rates and optical wavelengths. The port has a
single-mode fiber, universal optical input connector. To preserve the optical
integrity of the connector, keep the dust cover on the connector when not in use.
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POWER ON. This green LED illuminates when the receiver is powered on.
INPUT DETECTED ON. This green LED illuminates when the optical input signal
on the input connector is above the optical power threshold of the internal
photodetector.
REMOTE ENABLE. This switch toggles the remote mode of the receiver (and the
LED indicator) on and off when the switch is pressed. All front-panel controls
and status indicators, including Clock Recovery Module functions are accessible
through the Remote Interface when in remote mode.
OI2125 O/E Receiver Instruction Manual
Operating Basics
Remote Enabled. When power is first applied to the receiver, this green LED is
off, unless the remote interface Front Panel Unlock signal is low (active). If the
Front Panel Unlock signal is low, the LED is on, and will flash briefly when the
Remote Enable switch is pressed.
When the Front Panel Unlock signal is high at power-on, pressing the Remote
Enable switch toggles the LED on, indicating that the receiver is in remote
mode. Pressing the switch again returns the receiver to local (front panel) mode,
and the LED extinguishes.
DATA OUT (2). Two electrical data out connectors output the converted electrical
data signal. One of the outputs provides a signal to the Clock Recovery Module
Data input port, and the other output is available for measuring the quality of the
input optical signal with an oscilloscope or BERT. Generally, the Attenuated
Data Out signal from the receiver is connected to the Data In connector on the
Clock Recovery Module to keep from exceeding the maximum input voltage of
the module.
Clock Recovery
Module Port
The receiver has a front panel slot that accepts optional clock recovery modules.
A connector at the rear of the slot provides power and a control interface for the
modules. A slot cover module is a standard accessory for the receiver that should
remain installed in the receiver until a clock module is needed, to limit RF noise
and stray EMI emissions.
OI2125 O/E Receiver Instruction Manual
13
Operating Basics
Clock Recovery Modules
Clock Recovery Modules are available for the OI2125 O/E Receiver:
H The OM1420 clock recovery module provides clock recovery at one of two
The slot cover module is a standard accessory that plugs into the receiver module
slot when a clock recovery module is not used. See Figure 6.
selectable rates–OC-192 data rate (9.95328 Gb/s), and an OC-192 Forward
Error Correction data rate (10.66423 Gb/s).
Clock Recovery
Module Features
Data in Clock out
Data rate
indicator LEDs
Select rate
pushbutton
Hold-down screw
Figure 6: Clock Recovery Modules for the receiver
The Clock Recovery Module features are described as follows:
DATA IN. This SMA connector accepts electrical input from either the OI2125
O/E Receiver Attenuated Data Out port or from an external signal source. Use
the short SMA cable included with the module to connect to the receiver
Attenuated Data Out connector.
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CLOCK OUT. The recovered clock from the input signal is output on this SMA
connector.
SELECT RATE. A pushbutton switch selects between the data rates available in
the module. When you repeatedly push this momentary pushbutton switch, the
clock recovery module cycles through the data rates available in the module.
OI2125 O/E Receiver Instruction Manual
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