JDS Uniphase RM3750 User Manual
RM3 SERIES BACKREFLECTION METER
USER’S MANUAL
RM3 SERIES
BA CKREFLECTION METER
User’s Manual
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RM3 SERIES BACKREFLECTION METER
USER’S MANUAL
Contents
Safety Information, Instructions, and Symbols.......................................................................4
Safety Information...........................................................................................................4
Classification .......................................................................................................4
Disconnecting from Line Power...........................................................................4
Line Power Requirements ...................................................................................4
Fuse Type............................................................................................................4
Laser Specifications ............................................................................................4
Safety Instructions...........................................................................................................6
Before Initializing and Operating the Unit ............................................................6
Operating the Unit ...............................................................................................6
Safety Symbols...............................................................................................................8
Compliance.....................................................................................................................9
CE Compliance....................................................................................................9
FDA-CDRH Compliance......................................................................................9
CSA / IEC Compliance.........................................................................................9
General Information and Specifications................................................................................11
General Information ......................................................................................................11
Backreflection Measurements............................................................................12
Loss and Power Measurements ........................................................................12
Output Port........................................................................................................13
Internal Light Sources........................................................................................13
Hybrid Jumpers..................................................................................................13
Coherence Length.............................................................................................13
Electrical Requirements.....................................................................................13
Key Features.....................................................................................................13
Applications.......................................................................................................14
Standard Accessories........................................................................................14
Optional Accessories.........................................................................................14
Specifications................................................................................................................15
Getting Started........................................................................................................................18
Before Initializing and Operating the Unit......................................................................18
Initial I nspecti on.............................................................................................................18
Operating Environment.................................................................................................19
Altitude...............................................................................................................19
Temperature......................................................................................................19
Humidity.............................................................................................................19
Voltage ..............................................................................................................19
Storing and Shipping.....................................................................................................19
Claims and Repackaging...................................................................................19
Returning Shipments to JDS Uniphase.............................................................19
Cleaning Connectors.....................................................................................................20
Powering Up the Meter..................................................................................................21
Operating and Mainten ance Instructions..............................................................................22
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Front Panel....................................................................................................................22
Rear Panel....................................................................................................................23
Termination Techniques................................................................................................23
Termination Techniques for Single-mode Fiber (except 980 nm) ......................23
Termination Techniques for Single-mode (980 nm) and Multimode Fiber.........24
Backreflection Measurements.......................................................................................25
Setting Up the Meter for Backreflection Measurements.....................................25
Measuring Backreflection ..................................................................................26
Backreflection Accuracy and Range..................................................................27
Loss and Power Measurements....................................................................................27
Setting Up the Meter for Loss and Power Measurements .................................27
Measuring Power...............................................................................................28
Measuring Relative Power (Insertion Loss)........................................................29
Power Accuracy.................................................................................................30
Data Logging Using the Foot Pedal ..............................................................................30
Messages and Symbols................................................................................................30
Calibrating the Meter.....................................................................................................31
Backreflection Calibration Adjustment...............................................................32
Power Calibration Adjustment............................................................................32
Maintaining the Meter....................................................................................................33
Cleaning the Unit...............................................................................................33
Cleaning the Connector Ends............................................................................33
Recharging the Battery......................................................................................34
Replacement of Internal Fuses..........................................................................34
Troubleshooting.................................................................................................34
Programming Guide................................................................................................................37
RS232 Serial Interface..................................................................................................37
RS232 Pin Assignment......................................................................................37
RS232 Interface Specifications..........................................................................37
RS232-GPIB Converter.................................................................................................39
Left Dip Switch...................................................................................................39
Right Dip Switch................................................................................................39
Programming Examples................................................................................................40
RS232 Interface Program Example...................................................................40
Customized Features and Test Data......................................................................................41
For sales and service information,
contact JDS Uniphase or your local representative.
JDS Uniph ase Cor poration
570 West Hunt Club Road
Nepean, Ontario, Canada
K2G 5W8
Phone: 613 727-1303
Fax: 613 727-8284
E-mail: instruments@jdsuniphase.com
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RM3 SERIES BACKREFLECTION METER
USER’S MANUAL
Website: http://www.jdsuniphase.com
Safety Information, Instructions, and Symbols
Safety I n for m ation
Classification
The RM Series Backreflection Meter consists of an exposed metal chassis that is connected
directly to earth via a power cord and, therefore, is classified as a Class 1 instrument.
Disconnecting from Line Power
Some of the circuits are powered whenever the unit is connected to the AC power source (line
power). To ensure that the unit is not connected to the line power, disconnect the power cord
from either the power inlet on the unit’s rear panel or from the AC line-power source
(receptacle). The power cord must always be accessible from one of these points. If the unit is
installed in a cabinet, the operator must be able to disconnect the unit from the line power by
the system’s line-power switch.
Line Power Require ments
The RM meter operates from any single-phase AC power source that supplies between 100
and 240 V at a frequency range of 50 to 60 Hz. The maximum power consumption of the RM
meter is 25 VA. The unit can also be operated using its internal 6V DC rechargeable battery.
Fuse Type
The fuse type used by the unit is (5 x 20) mm, 1 A/250 V (fast).
Laser Specifications
Laser specifications are provided in Table 1.
Tabl e 1: S pecifications
Parameter Single-mode (SM) Multimode (MM)
Wavelength 980*, 1310, 1480, 1550, 1625,
or 1650 ± 10 nm
Class 1 1
Fiber Type 9/125 µm SM(*5/125 µm SM) 50/125 µm MM 62.5/125 µm
Maximum Accessible
Emission Level
Maximum Output Power -4 dBm -4 dBm -4 dBm
Numeric al Aperture 0.13 (*0.14) 0.20 0.28
Eff e ctive Nu me rical
Aperture
-15 dBm -23 dBm -25 dBm
0.20 (*0.21) 0.27 0.34
850, or 1310 ± 20 nm
MM
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Under the laser classification of the US Food and Drug Administration (FDA) Center for
Devices and Radiological Health (CDRH), the laser contained in the unit is a Class 1 laser.
CLASS 1
LASER PRODUCT
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Safety I n str u ction s
The following safety instructions must be observed whenever the unit is operated, serviced, or
repaired. Failure to comply with any of these instructions or with any precaution or warning
contained in the user’s manual is in direct violation of the standards of design, manufacture,
and intended use of the unit. JDS Uniphase assumes no liability for the customer’s failure to
comply with any of these safety requirements.
Before Initializing and Operating the Unit
Inspect the unit for any signs of damage, and read the user’s manual thoroughly.
Install the unit as specified in the Getting Started section.
Ensure that the unit and any devices or cords connected to it are properly grounded.
Operating t he Unit
Warning
To avoid the risk of injury or death, always observe the following precautions
before initializing the unit:
• To prevent hazardous radiation exposure, use only the controls or
adjustments and perform only procedures specified for the laser source.
• If using a voltage-reducing autotransformer to power the unit, ensure that
the common terminal connects to the earthed pole of the power source.
• Use only the type of power cord supplied with the unit.
• Connect the power cord only to a power outlet equipped with a protective
earth contact. Never connect to an extension cord that is not equipped with
this feature.
• Willfully interrupting the protective earth connection is prohibited.
• Never look into the end of an optical cable connected to an optical output
device that is operating. Laser radiation is invisible, and direct exposure can
severely injure the human eye. For more information, see the user’s manual
of the laser source in use.
• Do not use the unit outdoors.
• To prevent potential fire or shock hazard, do not expose the unit to any
source of excessive moisture.
• Do not operate the unit when its covers or panels have been removed.
• Do not interrupt the protective earth grounding. Any such action can lead to
a potential shock hazard that can result in serious personal injury.
• Do not operate the unit if an interruption to the protective grounding is
suspected. In this case, ensure that the unit remains inoperative.
• Use only the type of fuse specified by JDSU as appropriate for this unit. Do
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USER’S MANUAL
not use repaired fuses, and avoid any situations that can short-circuit the
fuse.
• Unless absolutely necessary, do not attempt to adjust or perform any
maintenance or repair procedure when the unit is opened and connected to
a power source.
• Repairs are to be carried out only by a JDSU qualified technician.
• Do not attempt any adjustment, maintenance, or repair procedure to the
unit’s internal mechanism if immediate first aid is not accessible.
• Disconnect the power cord from the unit before adding or removing any
components.
• Operating the unit in the presence of flammable gases or fumes is
extremely hazardous.
• Do not perform any operating or maintenance procedure that is not
described in the user’s manual.
• Some of the unit’s capacitors can be charged even when the unit is not
connected to the power source.
• If the equipment is used in a manner not specified by the manufacturer, the
protection provided by the equipment may be impaired.
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Safety Symbols
The following symbols and messages can be marked on the unit (Table 2). Observe all safety
instructions that are associated with a symbol.
Table 2: Safety Symbols
Symbol
WARNING
CAUTION
Description
Laser safety. See the user’s manual for instructions on handling and operating
the unit safely.
See the user’s manual for instructions on handling and operating the unit
safely.
Electrostatic discharge (ESD). See the user’s manual for instructions on
handling and operating the unit safely.
Frame or chassis terminal for electrical grounding within the unit.
Protective conductor terminal for electrical grounding to the earth.
The procedure can result in serious injury or loss of life if not carried out
in proper compliance with all safety instructions. Ensure that all
conditions necessary for safe handling and operation are met before
proceeding.
The procedure can result in serious damage to or destruction of the unit if not
carried out in compliance with all instructions for proper use. Ensure that all
conditions necessary for safe handling and operation are met before
proceeding.
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Compliance
CE Compliance
The unit has been designed and tested to comply with directive 73/23/EEC and its subsequent
amendments by the European Community (EC or CE). The directive relates to electrical
equipment designed for use within certain voltage limits. It ensures that electrical equipment is
constructed with good engineering pr actice in saf ety matters.
The unit has been designed and tested to comply with directive 89/336/EEC and its
subsequent amendments. The directive relates to electromagnetic compatibility. It demands
that electromagnetic disturbance does not exceed a prescribed level; that the equipment be
immune to a prescribed level of ambient level of interference ; tha t the equipment be protected
against electrostatic discharges; and that the equipment be immune to all electrical shock
wave disturbances. As of 1997, measures have been added to test for fire hazard, electric
shock hazard, and also external exposure to other forms of energy.
The requirements specified by directive 89/336/EEC are as follows. CE compliance requires
that the manufacturer or its authorized representative established within the Community affix
the CE conformity mark to the apparatus or else to the packaging, instructions for use, or
guarantee certificate. The CE conformity mark shall consist of the letters CE as specified and
the figures of the year in which the mark was affixed. This mark should, where appropriate, be
accompanied by the distinctive letters used by the notified body issuing the CE typeexamination certificate. Where the apparatus is the subject of other Directives providing for the
CE conformity mark, the affixing of the CE mark shall also indicate conformity with the relevant
requirements of those other Directives.
FDA-CDRH Compliance
Under the US Food and Drug Administration (FDA) Center for Devices and Radiological Health
(CDRH), the unit complies with the Code of Federal Regulations (CFR), Title 21, Subchapter J,
which pertains to laser safety and labeling. See http://www.fda.gov/cdrh/radhlth/cfr/21cfr1000-
1050.pdf for more information.
CSA / IEC Compliance
The unit complies with certain standards of the Canadian Standards Association (CSA) and
the International El ectrotechnical Commission (IEC).
The unit is in Installatio n Category (Overvoltage Category) II under IEC 664. IEC 664 relates to
impulse voltage levels and insulation coordination. The particular category is defined as: local
level, appliances, portable equipment, etc, with smaller transient overvoltages than Installation
Category (Overvoltage Category) III.
The unit is in the Pollution Degree 2 category under IEC 1010-1 and CAN/CSA-C22.2 No.
1010.1. The IEC standard on Safety Requirements for Electrical Equipment for Measurement,
Control, and Laboratory Use relates to insulation coordination. The CSA standard is on Safety
Requirements for Electrical Equipment for Measurement Control, and Laboratory Use, Part I:
General Requirements. The Pollution Degree 2 category is defined as follows: “Normally only
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non-conductive pollution occurs. Occasionally, however, a temporary conductivity caused by
condensation must be expected.”
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General Information and Specifications
General Information
This user’s manual for the RM3 Series Backreflection Meter contains complete operating
instructions. The RM meter can be ordered as a single-mode or multimode model. Software is
bundled with the meter; for information on using the software, see the
System Software User’s Manual
(document SD000318). The inspection report and a
description of any customer-requested information are found in Customized Features and
Test Data section.
The RM meter (Figure 1) is a portable, direct-display instrument that measures backreflection,
loss, and power of single-mode and multimode fiberoptic connectors, components, and
systems. The RM meter is supplied with one or two internal laser sources for operation at 850,
980,1310, 1480, 1550, 1625, or 1650 nm (not all combinations are available).
Multiple Connector Test
Figure 1: RM Meter
An important feature of the RM meter is the FC/APC ultra-low backreflection connector at its
output port (SC/APC connector also offered). By switching hybrid jumpers connected to the
FC/APC connector, the user can select the connector t ype required for a measurement quickly
and easily, without limiting the backreflection range of the meter. The RM meter is supplied
with a hybrid measurement jumper to be used exclusively for measurements and a hybrid
calibrated jumper to be used exclusively for calibrations.
The RM meter can be operated using an internal 6 V DC rechargeable battery.
The RM meter includes a convenient foot pedal, enabling the user to trigger the meter to send
measurement data to a computer or printer.
The RM meter operates over the RS232 serial interface. Wherever the IEEE 488 GPIB parallel
interface is mentioned, it is achieved via a RS232-to-GPIB converter that can be purchased as
an accessory.
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Backreflection Measurements
Reflection s in optical systems can come f rom a number of sources. P rimary sources include
the fiber (Rayleigh backscatter) and Fresnel reflections that occur at the planar junctio n o f two
materials having different refractive indices, for example, connector and fiber endfaces,
splices, bulk optic interfaces, and detector surfaces.
Typically only Fresnel reflections are significant because transmitters are relatively insensitive
to distributed reflections such as Rayleigh backscatter. Backreflection caused by Rayleigh
backscatter varies with the length and type of fiber, and is only significant when measuring
components with backreflections below -40 dB or with very long pigtails (multimode). However,
Rayleigh backscatter can be a la rge contributor to backreflectio n in installed syste ms or when
using long fiber.
The internal switch and coupler of the RM meter enable the meter to measure the internal light
source signal (P
and external backreflections (P
), the signal offset with no light (P
in
).
br
), and the total signal level from internal
dark
The RM meter first calculates the total backreflection from internal and external sources (BR
tot
using the following equation, where CAL is the factory-set calibration factor of the meter:
BR
= 10 log (Pbr - P
tot
)/(Pin - P
dark
) - CAL [dB]
dark
The backreflection from external sources (BR) is then calculated using the following equation,
where BR
is the stored value of the total backreflection up to the device under test (DUT), and
0
User CAL is the user-set calibration factor:
BR = 10 log (10
BR
tot
/10
- 10
BR
/10
0
) + User CAL [dB]
The RM meter then displays the value of BR.
The BR measurement takes approximately one second to complete. Before this is done, the
P
and P
in
measurements are completed in approximately four seconds, during which time
dark
the backreflection display is locked and the light from the output port is blocked. The values
are then updated every minute.
Loss and Power Measurements
The RM meter is equipped with a front-panel InGaAs detector for relative power (loss) and
absolute power measurements. (Absolute power is referred to as power in this manual; relative
power is always referred to as relative power.) Because the meter is capable of storing the
dark signal from the detector, high-accuracy power measurements as low as -80 dBm for the
single mode model (and –60 dBm for the multimode model) can be o btained.
),
When making power measurements, the RM meter first measures two signals: the total signal
level (I
) and the dark signal from the detector (ID). The RM meter then calculates the power
tot
measurement using the following equation, where CAL is the factory-set calibration factor and
User CAL is the user-set calibration factor:
P = 10 log (I
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- ID) + CAL + User CAL [dB]
tot
RM3 SERIES BACKREFLECTION METER
USER’S MANUAL
Output Port
The output port of the RM meter is equipped with an ultra-low backreflection APC connector.
To prevent damage to the output port connector, a measurement jumper must be used for all
measurements, even for measuring a component with an APC connector.
Internal Light Sources
The RM meter can be equipped with two internal laser sources. These are thermoelectrically
cooled for added stability and are modulated at 10 kHz. Fast changes in ambient temperature
can cause a source to become unstable. If this occurs, the meter automatically switches to a
measuring mode in which P
and P
in
are measured more frequently than every minute and
dark
the message “Source Unstable” is displayed. The light source power is monitored, and the
meter returns to the standard measurement mode when the source has stabilized.
Hybrid Jumpers
The RM meter is supplied with a hybrid measurement jumper and a hybrid calibrated jumper.
The measurement jumper has an APC connector at the input end. The other end on the
standard measurement jumper is PC, but by changing measurement jumpers this end is userselected, to be compatible with the input connector of the DUT. The calibrated jumper has an
APC connector at the input end and a PC connector at the output end.
Use the measurement jumper for measurement purposes only; use the calibrated jumper for
calibration purposes only. The calibrated jumper has a label attached to it identifying it as the
calibrated jumper.
Coherence Length
Reflected light from multiple reflections can change the backreflection measured by the
RM meter. This variation typically shows up as noise or drift in the signal. The internal light
source is designed to have low coherence length (typically less than 10 cm). Thus,
interference effects are typically seen only between very closely spaced components such as
non-contacting connectors.
Electrical Requirements
The RM meter is supplied with a rechargeable battery. When fully charged, the battery
provides up to eight hours of operation at room temperature. For laboratory use, use the
RM meter with the power cord. The letter B is shown on the RM meter front panel display when
the battery power is low.
Key Features
• Backreflection measurements to -75 dB for single mode model (-40 dB for multi mode
model)
• Power measurements to -80 dBm for single mode model (-60 dBm for multi mode model)
• Convenient foot pedal for data logging
• MCTS application software
• Built-in light sources at 850, 980, 1310, 1480, 1550, 1625, or 1650 nm
• Compensation for extraneous backreflection for accurate backreflection measurements
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