2004 Specifications CSJ 0924-06-244 SPECIAL SPECIFICATION 6734 RS-232 Optical Modem 1. Description. This Item shall govern for the furnishing and installation of Fiber Optic RS- 232 Data Modem (OTR) in field nodes and hubs as shown on the plans and as detailed in the Special Specifications. 2. Material. A. General Requirements. All materials furnished, assembled, fabricated or installed under this Item shall be new, corrosion resistant and in strict accordance with the details shown on the plans and in the specifications. B. Functional Requirements. The optical modem shall be a fault tolerant, self-healing device and shall provide high reliability, Electronic Industries Association (EIA) Compatible RS-232 data communications via a fiber optic communications link to and from multidrop interconnected field devices and host distribution nodes. The field devices include NEMA or Type-170 controllers, closed- circuit television pan-tilt controllers, dynamic message sign controllers and other similar controllers which may be associated with the City of El Paso Traffic Management System. The modem shall support uplink and downlink communications via fiber optic cables in a self-healing ring configuration. Two uplink fibers (one transmit and one receive) and 2 downlink fibers (one transmit and one receive) for a total of 4 fibers per each modem shall be employed. The modem shall optically communicate with other modem units interconnected to an overall host node, using compatible optical modulation. The modem shall include a repeating function, either uplink or downlink, depending on the source direction of the received signal. The modem shall be capable of receiving electrical RS-232 transmission and control signals from a field device connected to the unit and converting these RS-232 electrical signals to optically modulated signals in the uplink or downlink direction. The modem shall be capable of receiving optically modulated signals from either uplink or downlink devices, converting these optical signals to RS-232 electrical transmission and control signals and providing these signals to the distribution node connected. Receiver inputs from an uplink modem shall be repeated downlink and received inputs from a downlink modem shall be repeated uplink. 1-6 6734
Operating in conjunction with a host distribution node and field devices, the modem shall support near instant recovery from a broken fiber optic interconnect cable between all controller locations on a given ring. The transmitted and received data rate capability of the modem shall encompass all standard data rates up to 38.4 kbps without any baud rate adjustments of any kind. Full duplex asynchronous data transmission shall be accommodated. The transmitted and received data rate shall be able to change, at any time, within the above range without any mechanical adjustments to the modem. The modem shall include an anti-streaming (anti-babbling) logic control over electrical to optical signal transmission with a time-out changeable by the user. The time-out range shall be changeable to 4 seconds, 8 seconds, 16 seconds, 32 seconds, 64 seconds or infinity (disabled). The anti-streaming logic shall detect the presence of an RTS signal and data applied to the transmitted data port, and shall inhibit the CTS control signal and block the transmitted data port should the maximum selected transmission time be exceeded. When the anti-streaming logic has been activated it shall light a failure indicator on the modem, keep the CTS control signal inhibited and the transmitted data port blocked until a manual reset button, located on the modem, is depressed by maintenance personnel. The fiber optic transmitting and receiving devices shall operate at a single optical wavelength of 1300 nm nominally. Dual wavelength or WDM techniques shall not be employed. The fiber optic modem shall include two independent RS-232 channels, designated as "A" and "B" channels as shown on the plans. C. Electrical/Optical Requirements. 1. Transmitting Device. The transmitting device shall be capable of operating over singlemode fiber optic cable. 2. Transmitter Optical Output. Output power to 8/125 singlemode dual window glass fiber at wavelengths of 1300 nm/1550 nm, shall be sufficient to accommodate a link loss budget of 12 db or more at each wavelength. Once design is tested and approved, the optical coupled power value and tolerance will become incorporated as part of this specification for the purpose of acceptance tests. 3. Optical Detector. The optical detector of the receiver shall be a Pin diode. 4. Receiver Optical Input. Receiver input shall have a minimum sensitivity of 12 db, at each wavelength, below the transmitter output level and operate within the parameters of this specification. 2-6 6734
Once the design is tested and approved, the receiver sensitivity value and tolerance shall be incorporated as a part of this specification for the purpose of acceptance tests. 5. Receiver Automatic Gain Control. The receiver shall have automatic gain control (AGC) circuitry to provide the receiver with the required dynamic range from transmitter- receiver spacing of 0 to 12 db at each wavelength. The above dynamic range requirements may be accomplished with external optical attenuators with the approval of the Engineer. 6. Transmitting/Receiving Devices. The transmitting/receiving devices shall have a minimum mean time between failure (MTBF) of 100,000 hours at 122 F ambient. 7. Modulation. Modulation shall be FM. 8. Operating Mode. Asynchronous, full duplex. 9. Input/Output Impedance. Per RS-232. 10. System Bandwidth. DC to 38.4 Kbaud minimum. 11. Optical Fiber Compatibility. Optical Fiber Compatibility shall be 8/125 micron singlemode, however the modem shall also be available at 62.5/125 micron (graded index) dual window multimode glass fiber. 12. Data Performance Requirements. Digital data transmitted and received by the OTR shall conform to all the requirements of EIA Standard RS-232. 13. Data Rate. The OTR shall support data transmission rates from 0 bits/sec up to and including 38,400 bits/sec. 14. Bit Error Rate (BER). The bit error rate of each data channel shall not exceed 10 to the -9 power within optical budget. 15. Power Requirements. Each OTR shall operate at 12 to 24 VAC or VDC from a separate power supply to be provided as part of this bid item and shall not draw more than 5 watts of power each. The separate power supply shall operate from 115 VAC ± 10%, 60 Hz ± 3 Hz. The equipment operation shall not be affected by the transient voltages, surges and sags normally experienced on commercial power lines. It is the Contractor's responsibility to check the local power service to determine if any special design is needed for the equipment. The extra cost, if required, shall be included in the bid of this item. 16. Surge Protection. Appropriate Surge protectors shall be installed in the cabinet. 17. Power Service Transients. The equipment shall meet the requirements of Sec. 2.1.6, "Transients, Power Service" of the NEMA Standard TS2-1992, or the latest revision. 3-6 6734
18. Wiring. All wiring shall meet the requirements of the National Electric Code. All wires shall be cut to proper length. Cable slacks shall be provided to facilitate removal and replacement of assemblies, panels, and modules. No wire shall be doubled back to take up slack. Wires shall be neatly laced into cable with nylon lacing or plastic straps. Cables shall be secured with clamps. 19. Transient Protection. All DC relays, solenoids, and holding coils shall have diodes or other protective devices across the coils for transient suppression. 20. Power Service Protection. The equipment shall contain readily accessible, manually resettable or replaceable circuit protection devices (such as circuit breakers or fuses) for equipment and power source protection. 21. Fail Safe Provision. The equipment shall be designed such that the failures of the equipment shall not cause the failure of any other unit of equipment. D. Mechanical Requirements. 1. Modular Design. The equipment shall be modular in design to allow major portions to be readily replaced in the field. Modules of unlike functions shall be mechanically keyed to prevent insertion into the wrong socket or connector. All modules and assemblies shall be clearly identified with name, model number, serial number, and any other pertinent information required to facilitate equipment maintenance. 2. Connectors and Harnesses. All external connections shall be made by means of connectors. The connectors shall be keyed to preclude improper hookups. All wires to and from the connectors shall be color coded and/or appropriately marked. Each and every conductive contact surface or pin shall be plated with a minimum of 20 microns of gold. Connecting harness of appropriate length and terminated with matching connectors shall be provided for interconnection with the terminal equipment shown on the plans, or as directed by the Engineer. 3. Housing. The OTR shall be available in standard compact serviceable modules. Dimensions of each OTR shall not exceed 4.0 in. D x 7.1 in. W x 2.0 in. H. The modems at the remote hub locations shall be rack mountable in a compatible card cage. E. Environmental Design Requirements. The equipment shall meet all its specified requirements during and after subjecting to any combination of the following requirements. - -Ambient temperature range of 1.4 to 158 F. - -Relative humidity from 0% to 95%. 4-6 6734
3. Construction. A. General. The equipment design and construction shall utilize the latest available techniques with a minimum number of parts, subassemblies, circuits, cards, and modules to maximize standardization and commonality. The equipment shall be designed for ease of maintenance. All component parts shall be readily accessible for inspection and maintenance. Test points shall be provided for checking essential voltages and waveforms. B. Electronic Components. All electronic components shall comply with Special Specification, "Electronic Components". C. Mechanical Components. All external screws, nuts, and locking washers shall be stainless steel; no self-tapping screws shall be used unless approved by the Engineer. All parts shall be made of corrosion resistant material, such as plastic, stainless steel, anodized aluminum, or brass. All materials used in construction shall be protected from fungus growth and moisture deterioration. Dissimilar metals shall be separated by an inert dielectric material. 4. Documentation Requirements. The documentation requirements shall be in accordance with the Special Specification, "Testing, Training, Documentation, Final Acceptance and Warranty", Article 4. 5. Testing. The testing shall be in accordance with the Special Specification, "Testing, Training, Documentation, Final Acceptance and Warranty", Sections 2. - 2.(6). Testing shall include the following: Data Performance Tests. Digital data performance testing shall include all necessary tests to ensure compliance with all of the requirements of EIA Standard 2 3 2. These tests shall, as a minimum, demonstrate data communications between each of the data channel units in the control center and the corresponding data channel units in the field. Using a loopback plug at each EIA-232 channel terminating at a field location, a 24 hour bit error rate test (BERT) for each channel shall be conducted using a data communications test set in the control center. This BERT is used to determine the bit error rate (BER) through the system and terminating equipment at each end, and to certify that the EIA-232 channels can operate at a sustained rate of 9600 bits/sec (bps) for a 24 hour period. The 511-bit CCITT standard pseudo-random pattern shall be used for testing. The BER measured at 9600 bps shall not exceed the requirements of Section 2.(3.)14 of this specification, and the error free seconds (EFS) shall be better than 99.98%. If this BER is exceeded on any channel, the problem shall be corrected and the entire BERT shall be completely restarted from the beginning, as if no previous BERT had been conducted. If a component has been modified as a result of the subsystem test failure, a report shall be prepared and delivered to the Engineer prior to re-testing. 6. References. The OTR Supplier shall submit 3 references, preferably State Departments of Transportation, that have been successfully operating a data transmission system supplied by 5-6 6734
this supplier, for a period of no less than one year. Reference data shall include name and address of organization, and the name and telephone number of an individual from the organization who can be contacted to verify system. 7. Training. The training shall be in accordance with Special Specification, "Testing, Training, Documentation, Final Acceptance and Warranty.", Article 3. 8. Warranty. The warranty shall be in accordance with the Special Specification "Testing, Training, Documentation, Final Acceptance and Warranty", Article 6. 9. Measurement. This Item will be measured as each unit furnished, installed, made fully operational and tested in accordance with these Special Specifications or as directed by the Engineer. 10. Payment. The work performed and materials furnished in accordance with this Item and measured as provided under "Measurement" will be paid for at the unit price bid for "RS-232 Optical Modem". This price shall include all equipment described under this Item with all cables and connectors, all documentation and testing; and shall include the cost of furnishing all labor, materials, training, warranty, equipment, and incidentals. 6-6 6734