WAVECREST Corporation OE-2 Optical to Electrical Signal Converter User’s Guide and Reference Manual 200005-01 REV A
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WAVECREST Corporation continually engages in research related to product improvement. New material, production methods, and design refinements are introduced into existing products without notice as a routine expression of that philosophy. For this reason, any current WAVECREST product may differ in some respect from its published description but will always equal or exceed the original design specifications unless otherwise stated.
ATTENTION: USE OF THE SOFTWARE IS SUBJECT TO THE WAVECREST SOFTWARE LICENSE TERMS SET FORTH BELOW. USING THE SOFTWARE INDICATES YOUR ACCEPTANCE OF THESE LICENSE TERMS. IF YOU DO NOT ACCEPT THESE LICENSE TERMS, YOU MUST RETURN THE SOFTWARE FOR A FULL REFUND. WAVECREST SOFTWARE LICENSE TERMS The following License Terms govern your use of the accompanying Software unless you have a separate written agreement with Wavecrest. License Grant. Wavecrest grants you a license to use one copy of the Software.
OE-2™ User’s Guide and Reference Manual Table of Contents Preface Organization and Inspection ........................................................... v SECTION 1 Introduction ...................................................................................... 1 Features .......................................................................................... 1 How the OE-2 Works ...................................................................... 2 Laser Safety .................................
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PREFACE Organization The manual is divided into three Sections and three Appendices. The following is a brief description of the information contained in each section. For quick reference to specific information, refer to the Table of Contents. SECTION 1 — Introduction This section introduces the user to the OE-2. Features and capabilities are described. An overview of the internal operation of the OE-2 is also included. SECTION 2 — Description Describes the front and back panels of the OE-2.
Inspection If the contents are incomplete or damaged, contact WAVECREST Service: 1-800-733-7128. Corporation Customer Inspect the shipping box for damage. If the shipping box is damaged, or the cushioning materials show signs of stress, notify the shipping carrier as well as the WAVECREST Corporation office. Keep the shipping materials for the carrier’s inspection. Check for accessories.
SECTION 1– Introduction The WAVECREST OE-2 converts optical communications signals into electrical signals. In combination with a WAVECREST DTS or SIA system, the OE-2 enables accurate, high performance jitter measurements on optical signals. The OE-2 can be operated in local mode or it can be controlled through its GPIB interface using WAVECREST’s Virtual Instruments™ Signal Integrity (VISI) software.
How the OE-2 Works The OE-2 consists of a high-performance optical-to-electrical converter followed by widebandwidth, signal processing devices. Dual-channel models incorporate two identical channels. The block diagram below shows the structure of one OE-2 channel. Figure 2 – Block diagram of an OE-2 channel The optical input signal is converted to an electrical current using a low-noise, temperaturestabilized photo receiver.
Laser Safety Although the OE-2 optical to electrical converter does not emit laser energy, it does process optical signals from laser devices. Therefore, laser signals will be present at the OE-2 inputs. These signals present retinal and/or personal hazards because they are invisible and might not be detected until injury to the eye or skin has occurred. To prevent injuries, basic precautions should be followed. • NEVER look directly into an optical signal connector. Always assume a laser beam is present.
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SECTION 2 – Front and Back Panel Descriptions This section describes the front and back controls and connectors of the OE-2. 1 2 9 3 4 5 6 7 8 Dual Channel OE-2 Front panel Front Panel Controls and Connectors 1 Filter Selection The OE-2 routes the converted signal through low-pass filters to establish a finite, repeatable measurement bandwidth for the OE-2. Fourth-order Bessel-Thomson low pass filters are exclusively used.
3 Over range LED/Signal LED Two LEDs on the front of the OE-2 indicate optical input signal status. The lower “SIGNAL” LED is lit when the OE-2 senses an optical signal. If the upper “OVERRANGE” LED is blinking red, the optical signal power is beyond the input range of the instrument and should be removed to prevent damage to the optical detector. If both LEDs are blinking, the O/E receiver temperature stabilization is not within range. Measurements made during this condition are not valid.
Back Panel Controls and Connectors 12 10 11 13 14 15 16 OE-2 Back Panel 10 11 12 AC Input Port IEC Inlet for AC cord. Connect to an AC source in the range of 100-264 VAC, 47-63 Hz. Fuse Primary AC fuse. Located inside of connector housing. Should be replaced with two Wickman 4AT/250V fuses (5x20 mm). Reset Pushbutton The Reset Pushbutton resets the microprocessor in the OE-2 and sets the instrument to default filter and amplifier settings (the topmost filter setting and 10 dB, respectively).
15 16 GPIB Input Connector Connector for GPIB cable. Used for controlling the OE-2 with a computer or other instrument. A GPIB device address can be set using the 32-position DIP switch (see below), with address 0 reserved for the controller and the remainder of the settings available at the user’s discretion. A full GPIB command set is provided in Section 3. GPIB Port Address Switch Sets the address of the GPIB port. The address can be set from 1 to 31.
SECTION 3 – Setup and Measurement This section describes the set-up of the OE-2 and provides instructions that enable the user to take a quick measurement for rapid familiarization with the instrument. In addition, this section describes the Virtual Instrument Signal Integrity™ (VISI) software tools necessary for using the OE-2 with any WAVECREST measurement instrument. Please refer to the VISI User’s Guide for detailed definitions and instructions of this and other VISI tools.
VISI SOFTWARE SETUP Controller Mode Edit | Configuration Menu In order for the OE-2 to communicate with the SIA-3000™ using the GPIB bus, the SIA3000 must be in the “Controller” mode. To select Controller mode: Select Edit | Configuration on the (pull-down) Menu Bar Select OE-2 in the Target Device pull-down Menu Select Controller in the GPIB Board Mode pull-down menu.
Manually Assigning GPIB Addresses The GPIB Address Assignment window will appear (see figure below). The fields in this dialog box will be blank unless device assignments were previously made. The GPIB Address Assignments dialog box manages the address settings for both the GPIB host and all OE-2’s. Optical Configuration Dialog Box – GPIB Address Assignment The Optical GPIB Board field controls the host GPIB address, that is, the GPIB address of the SIA controller or host controller computer.
When all OE-2’s connected to the system are addressed, the next step is to poll the GPIB bus to see that each OE-2 is correctly addressed. This is done with the Optical Channel Assignment dialog box. Clicking on the Optical Channel Assignment tab will initiate the polling process. Each correctly addressed OE-2 will be shown in the Optical Input window along with its GPIB device address. If a connected OE-2 does not appear in the dialog box, its address may be incorrectly set.
Setting Acquire Options The Acquire Options dialog bar displays the OE-2 settings for optical signal measurements. In setting the Acquire Options, note that “channel” refers to the DTS or SIA channel. To set the Acquire Options: From the Main Dialog Bar, select Utilities. The Utilities dialog bar will be displayed. From the Utilities Dialog Bar, select Optical Interface. The Optical Interface tool will be displayed. From the Optical Interface Dialog Bar, select Acquire Options.
Select the channel to view. (“Channel” refers to the DTS or SIA channel.) The software will poll the OE-2 configured to that channel to determine which filter bank options are installed. WAVECREST’s VISI software has preprogrammed set-ups for several popular communication standards, including Fibre Channel, Gigabit Ethernet, and Infiniband. When you select one of these filter set-ups, VISI will automatically select the filter and amplifier in the OE-2 and set the wavelength for measurements.
External Calibration An external calibration must be performed for each channel. Keep in mind that, when you press the “External Calibration” button, only the channel that is selected in the “Channel” field will be calibrated.
Output Setting Options The Output Settings dialog bar enables the user to set the units of measure, such as milliwatt or microwatts, for optical measurements. Pass/fail limits for optical power, modulation and rise and fall time measurements are accessible through this selection. To access the Output Settings, select the Output Settings button on the Dialog Bar. Select the appropriate optical settings from the drop-down menus or enter the desired value into the available data fields.
Trigger Options The Trigger Dialog Bar enables the user to set up trigger sources and conditions on the DTS or SIA instrument. Trigger - Select trigger source. Trigger Method - Select Auto to set the trigger threshold voltage to the 50% voltage point of the Pulsefind values on the selected trigger channel. Voltage is displayed in "Trigger Voltage." Select "User" to manually enter a threshold voltage in "trigger Voltage." Limits are +/- 1.1 volts.
Taking a Measurement Two types of measurements are available once the setup of the instrument has been completed and are available from the Tool Bar or the Action pull-down menu. • Single/Stop command (Action menu) Use this command to acquire a single measurement in VISI. It is also used to stop a series of measurements from being taken after the Run command is issued. This command affects the current tool only.
APPENDIX A – Specifications and Requirements OE-2™ SPECIFICATIONS Functional Specifications—Optical Wavelength Range ...................................................770 to 1650 nm Conversion Gain(850nm)1,2......................................5,500 V/W (850 nm/40 dB amp) Conversion Gain(1550nm) 1,2 ...................................20,000 V/W (1550 nm/40 dB amp) Maximum Input Level3 ............................................+3 dBm Input Damage Level.................................................
Calculated Measurement Accuracy 1 Extinction Ratio12 ..................................................±1 dB Notes: 12. Using an SIA-3000, M3.2 Channel Card, VISI software with a 100-125 MHz square wave, 850 nm, average optical power level of –5 dBm (per Fibre Channel or Gigabit Ethernet standards) 0 -1 Responsivity (dB) Optical Modulation Amplitude12,13 ....................... ±12% -2 -3 -4 -5 -6 -7 13. Percent of reading.
Interface Requirements The optical inputs are high return loss FC/UPC connectors. Either single mode or multi-mode fibers can be accepted. The electrical outputs are SMA connectors. The OE-2 includes an IEEE-488 interface. The connector and address selection switch are located on the rear panel of the instrument. Power Requirements The OE-2 operates on 100-120 VAC & 200-240 VAC (±10%), 47-63Hz. The OE-2 is rated for 275 Watts. Fuses: (2) two 2AT/250V, 5 x 20 mm. Power supply is auto ranging.
Maintaining Proper Instrument Grounding Both 120VAC and 230VAC power sources require an earth ground at the power connection. Failure to provide this safety ground could result in improper measurements and/or electrical shock danger to the operator. Only qualified service personnel should perform maintenance procedures on the OE-2. When maintenance is performed, NO protective earth ground connections should be removed.
APPENDIX B - GPIB Commands The following GPIB commands are supported in the OE-2. Table B1. IEEE.
Table B3. OE-2 Specific Commands Command Command Syntax Query Syntax CHANnel (Root command) :CHANnel Valid strings: 1 - Channel1, 2 – Channel2 CHANnel ? INStalled No write command. :INStalled ? Return value: comma delimited string as follows: TYPE, FILT,AMPL,WAVE are defined later in the table. MODEL refers to the # of channels, SING or DUAL. VERSION refers to the hardware release (6 charactrers, BXX.XX for Beta and RXX.XX for production.
Table B3. OE-2 Specific Commands cont. Command Command Syntax Query Syntax NULLoffset :NULLoffset Used to calibrate the OE-2 when no optical power is present. When using a short calibration no string is required. When using a long cal the string represents the null offset in bits. :NULLoffset ? Return value: Floating point value representing the last stored null offset of the OE-2.
FILTer: Channel subcommand that sets the filter for the specified channel or reads the current setting. Valid filter settings depend upon the type of channel that is installed in the OE-2. Valid settings can be determined from the TYPE field of the INStalled query. Example read: ‘:CHAN1:FILT?’. INStalled: Channel subcommand that provides a query response only. When queried the command returns a comma delimited field with information pertaining to the specified channel.
APPENDIX C – Preprogrammed Measurement Limits The following Charts show the preprogrammed measurement limits for each OE-2 model. See Section 3 for more information on the measurement limit presets. Table C1. OE-2 Option 1 Filter Protocol Wavelength Power Units Average Power Limit Modulation Measure Modulation Units Modulation Rise/Fall times Limit Limits (in ps) “User Defined” Defaults “Filter 1” 850 nm dBm (1) OMA uW (1) (1) Gigabit Ethernet 1000BASE-SX GE 850 nm dBm -9.
Table C1. OE-2 Option 2 Filter Protocol Wavelength Power Units Average Power Limit Modulation Measure Modulation Units Modulation LImit Rise/Fall times Limits (in ps) “User Defined” Defaults “Filter 1” 850 nm dBm (1) OMA uW (1) (1) Gigabit Ethernet 1000BASE-SX GE 850 nm dBm -9.5 ER dB 9 260 rise 210 fall Gigabit Ethernet 1000BASE-LX Single Mode GE 1300 nm dBm -11.0 ER dB 9 260 Gigabit Ethernet 1000BASE-LX Multimode GE 1300 nm dBm -11.
Table C1. OE-2 Option 3 Protocol Filter Wavelength Power Units Average Power Limit Modulation Measure Modulation Units Modulation Limit Rise/Fall times Limits (in ps) “User Defined” Defaults “Filter 1” 850 nm dBm (1) OMA uW (1) (1) Gigabit Ethernet 1000BASE-SX GE 850 nm dBm -9.5 ER dB 9 260 rise 210 fall Gigabit Ethernet 1000BASE-LX Single Mode GE 1300 nm dBm -11.0 ER dB 9 260 Gigabit Ethernet 1000BASE-LX Multimode GE 1300 nm dBm -11.
Table C1. OE-2 Option 4 Protocol Filter Wavelength Power Average Power Units Limit Modulation Measure Modulation Units Modulation Limit Rise/Fall times Limits (in ps) “User Defined” Defaults “Filter 1” 850 nm dBm (1) OMA uW (1) (1) Gigabit Ethernet 1000BASE-SX GE 850 nm dBm -9.5 ER dB 9 260 rise 210 fall Gigabit Ethernet 1000BASE-LX Single Mode GE 1300 nm dBm -11.0 ER dB 9 260 Gigabit Ethernet 1000BASE-LX Multimode GE 1300 nm dBm -11.
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