NOTE: Match the input and output configurations to
the equipment to be interconnected. The data rate
of the FO modem must exceed the data rate of the
devices served.
**************************************************************************
FO modems shall accept inputs and provide outputs compatible with [EIA
ANSI/EIA/TIA-232-F] [EIA ANSI/TIA/EIA-485-A] [20 mA current loop] [T1] [10
Base-F]. Digital data rates through each link shall be [9.6 KBPS] [19.2
KBPS] [38.4 KBPS] [1.54 MBPS] [10 MBPS].
2.2
FO TRANSMITTER AND RECEIVER MODULES
**************************************************************************
NOTE: There are several ways fiber optic
transmitters and receivers can be implemented such
as:
a. The transmitter and receiver can be mounted on a
logic board. The transmitter and receiver are then
an integral part of the system at the logic level.
b. The transmitter and receiver can be individual
modules which are mounted external to the logic
boards. They can be powered by their own power
supplies and can communicate with the serial data
ports of the logic boards at logic levels.
c. The fiber optics transmitter and receiver can be
combined with interface and control logic to form a
fiber optic modem. The system field equipment can
thus communicate with the modem over a EIA 232-F
serial data port.
The designer must determine where FO communication
devices will be located. In many systems, FO
transmitters and receivers or modems are located in
the field equipment enclosures of the systems being
supported by the FO system. Often, these FO devices
are physically mounted on circuit cards or modules.
In other cases, FO devices will have to be installed
in separate enclosures provided with the FO system.
This is often the case for FO repeaters and active
star units.
**************************************************************************
FO transmitter/receiver pairs shall have signal-to-noise power ratio of 40
dB or better after photo detection at the receiver. Transmitter power
output and receiver sensitivity shall not drift more than plus or minus 2
dB over their operational life.
2.2.1
Analog FO Transmitter and Receiver Modules
FO transmitter/receiver pairs used to pass analog video signals shall
accept inputs and provide outputs that comply with EIA 170 and shall have a
bandwidth of 6 MHz or greater.
SECTION 16768A
Page 18
Previous Page
