FIBRE OPTIC MODEMS - Item No.
Special Provision No. 683S09
1.
September 2007
SCOPE
This Special Provision covers the requirements for the installation and testing of fibre optic modems (FOM).
2.
REFERENCES
This Special Provision refers to the following standards, specifications, or publications:
Electronic Industries Alliance / Telecommunications Industry Association:
EIA/TIA-232-E
Interface Between Data Terminal Equipment and Data Circuit-Terminating
Equipment Employing Binary Data Interchange
TIA/EIA-404-B
Standard for Start-Stop Signal Quality for Non-Synchronous Data Terminal
Equipment
EIA-RS-310-D
Cabinets, Racks, Panels and Associated Equipment
3.
DEFINITIONS – Not Used
4.
DESIGN AND SUBMISSION REQUIREMENTS
4.1
Submission Requirements
The Contractor shall supply the specification sheets for the fibre optic modems to the Contract Administrator
for review prior to ordering.
5.
MATERIALS
5.1
Fibre Optic Modem
5.1.1
General
5.1.1.1
The FOM shall provide full duplex communication between two TIA/EIA-232-E data ports
and shall allow a multidrop communications circuit to be formed using a pair of optical fibres
as the transmission medium.
5.1.1.2
The FOM shall be configured as DCE.
5.1.1.3
The FOM shall be supplied with a cross connect device to permit communications between
two DCE ports. The cross connect device may be internal to the FOM and selectable to
provide DTE or DCE interface.
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SSP683S09
5.1.1.4
The FOM shall be configurable to operate in two modes designated as the repeater mode and
the feeder mode. Selection of the operating mode shall be performed by means of a switch
easily accessible without disassembly of the FOM.
5.1.1.5
A FOM which is to be electrically connected to a DCP or a PSD shall be cross connected to
provide DCE to DCE interface and shall operate in the feeder mode.
5.1.1.6
A FOM which is to be electrically connected to a field controller or a Camera Control
Receiver shall be configured to provide DTE to DCE interface and shall operate in the
repeater mode.
5.1.1.7
Two FOMs interconnected by optical fibre shall provide full duplex communications on
circuits BA and BB. The setting of circuit CA ON on either FOM shall result in circuit CF
turning ON on the other FOM. Circuit identification shall be in accordance with TIA/EIA232-E.
5.1.1.8
The FOM shall raise Clear to Send ON after it detects Request to Send ON.
5.1.1.9
The Contractor shall coordinate the Request to Send to Clear to Send delay with the DCP so
as to minimize system data delay and to not lose any data. The Request to Send to Clear to
Send delay shall not exceed 0.5 ms.
5.1.1.10
It shall be possible to interface two FOMs in the feeder mode through one or more FOM in
the repeater mode.
5.1.1.11
All interconnections between FOMs shall be by multimode optical fibre.
5.1.1.12
A FOM shall have four optical ports (two transmitters and two receivers). Two of the ports
(one transmitter and one receiver) shall be designated for upstream communication and two
shall be designated for downstream communication.
5.1.1.13
When selected to operate in the repeater mode the FOM shall operate as follows:
5.1.1.14
a)
All data information received through the upstream receiver shall be output on the
TIA/EIA-232-E interface and shall be repeated through the downstream transmitter
b)
When Request to Send is OFF on the FOM TIA/EIA-232-E interface, all data and
control signal information received through the downstream receiver shall be
repeated through the upstream transmitter
c)
When Request to Send is ON on the FOM TIA/EIA-232-E interface, all data and
control signal information received through the downstream receiver shall be
inhibited and all data and control signal information received from the TIA/EIA-232E interface shall be transmitted through the upstream transmitter
When selected to operate in the feeder mode the FOM shall operate as follows:
a)
September 2007
All data information received from the upstream and downstream receivers shall be
output on the TIA/EIA-232-E interface.
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SSP683S09
b)
All data information received from the TIA/EIA-232-E interface shall be output
through the upstream and downstream transmitters.
5.1.1.15
Each FOM shall transmit information to another FOM through multimode optical fibre by
means of a LED and all required bias circuitry.
5.1.1.16
LEDs shall transmit with a centre wavelength of between 820 nm and 870 nm at 25o C. LEDs
shall be coupled to optical fibre through an ST style compatible connector or panel mount
receptacle mounted on the FOM.
5.1.1.17
The LED launch power shall be equal to or greater than 13 db greater than the receiver
sensitivity.
5.1.1.18
The receiver shall be coupled to the optical fibre through an ST style compatible coupling or
panel mount receptacle mounted on the FOM.
5.1.1.19
The receiver sensitivity shall be defined as the minimum optical power required to be
received by the receiver to operate with a bit error rate of 10-9.
5.1.1.20
Two FOMs interconnected by optical fibre with a total optical attenuation between 3 and 13
dB shall provide data communication between two TIA/EIA-232-E ports at a speed of 9600
baud with the created pulse width distortion not exceeding 1.5 µs.
5.1.1.21
Pulse width distortion shall be defined as the difference between the pulse width into one
FOM TIA/EIA-232-E port and the output pulse width from the TIA/EIA-232-E port of an
interconnected FOM. Pulse width shall be measured in units of time between the mark-tospace and space-to-mark transitions of any particular data bit measured in accordance with
TIA/EIA- 404-B.
5.1.1.22
The FOM shall include all mounting hardware to mount it in an existing EIA standard 480
mm equipment rack supplied by the Ministry in each cabinet.
5.1.1.23
The FOM shall have a D-Type 25 pin connector providing an TIA/EIA-232-E compatible
interface.
5.1.1.24
Pins 1, 2, 3, 4, 5, 6, 7, 8 and 20 shall be assigned in accordance with TIA/EIA-232-E. All
other pins of the electrical interface shall not be connected.
5.1.1.25
LEDs shall be derated so that the peak optical power is emitted at least 3 dB below the power
launched when driven at the maximum rated drive current.
5.1.1.26
The LED launch power shall be defined as the power launched by the LED into one metre of
graded index optical fibre with a nominal core dimension of 62.5 µm, a nominal cladding
dimension of 125 µm and a theoretical numerical aperture of 0.29.
5.1.1.27
Each FOM receiver shall receive information from the optical fibre by means of PIN
photodiode and all required circuitry.
5.1.2
5.1.2.1
September 2007
Power Supply
The FOM power supply shall meet the following requirements:
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SSP683S09
a)
The power supply shall operate from an input voltage of 120 V 60 Hz nominal
b)
The power supply shall have DC outputs rated to meet the voltage and current
requirements of the FOM
c)
Output current shall be protected against damage in the event of a short circuit
d)
The power supply shall have a minimum Mean Time Between Failure of 50,000
hours
6.
EQUIPMENT – Not Used
7.
CONSTRUCTION
7.1
FOMs shall be installed in the cabinets identified in the drawings and shall share the available
equipment space with existing equipment.
7.2
The drawings show the equipment space allocated to FOMs and PSDs for typical cabinet
arrangements.
7.3
The Contractor shall coordinate the physical space required by the FOMs or PSDs required to
be collocated to ensure that they will be accommodated in the allocated space.
7.4
The Contractor shall connect the FOM power supply to one of the 115VAC 60 HZ power
distribution panel receptacles reserved for communication equipment.
7.5
Each FOM shall be configured as DCE or DTE and shall be selected to operate in repeater or
feeder mode in accordance with the Contract.
7.6
The Contractor shall connect the correct Drop Cable connectors to each FOM in accordance
with the drawings.
7.7
When connecting optical communication equipment, the Drop Cables shall be neatly trained
along the rails of the equipment rack.
7.8
No Drop Cables shall be installed with a bending radius exceeding the manufacturer’s
minimum recommended bending radius.
7.9.
Quality Control
The Contractor is responsible for all testing and documentation required to establish approval and acceptance
of installation and operation of this equipment. The framework of the approval process shall be as specified
elsewhere in the Contract Documents.
The following table details the clauses within this Special Provision, which are to be validated through the
PIT, POP, and SIT processes as indicated:
CLAUSE
September 2007
PIT
POP
SIT
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CLAUSE
PIT
POP
5.1.1.1
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5.1.1.2
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5.1.1.3
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5.1.1.4
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5.1.1.5
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5.1.1.6
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5.1.1.7
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5.1.1.8
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5.1.1.9
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5.1.1.10
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5.1.1.12
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5.1.1.13
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5.1.1.14
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5.1.1.17
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5.1.1.19
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1
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SIT
2
Testing Footnotes:
1
All testing to be done at a bit error rate of 10-9.
2
Test 2 fibre optic modems at a bit error rate of 10-9, and the rest at 10-7.
8.
QUALITY ASSURANCE - Not Used
9.
MEASUREMENT FOR PAYMENT
Measurement for payment of the number of fibre optic modems is by Plan Quantity as may be revised by
Adjusted Plan Quantity.
The unit of measurement is each.
10.
BASIS OF PAYMENT
Payment at the Contract price for the above tender item shall be full compensation for all labour, Equipment
and Material required to do the work including delivery, installation, testing and the production of all
drawings, text and test results, except for SIT which is paid for under a separate item.
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SSP683S09
WARRANT:
September 2007
Always with this item.
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SSP683S09