16 August 06 FDM-FSK Preliminary User Guide 5 Dwg: A01230
FDM SERIES OVERVIEW continued
A unique and intuitive Dual Seven Segment display graphically indicates the
status of the fiber system, making diagnostics visually simple. All FDM series
modems have the unique capability of Fiber Identification; the display will flash a
1 or 2 indicating which circuit the fiber belongs to.
Other advantages include multiple use Dual Data Ports enabling branch circuit
capabilities such as an On Street Master to Local Controller (same location), or
4wire or Spread Spectrum Radio communications.
All modems have the unique capability of having their Auxiliary Port switched
from DCE to DTE mode. This feature allows the Main port to drive the Aux-Port
as well as the fiber, primarily used for Street Master communications with the
local controller or driving some other modem.
Only FDM optical modems have the unique ability to generate a Carrier Detect
both before and after data flow, this is essential when connecting to 2 Wire FSK
communications. This Dynamic CD acts like a “DTE’s RTS” and is used to
initiate handshaking to a DCE’s RTS input.
The FDM Series represents a new generation of digital fiber optic modems
utilizing a Replaceable Operating System (ROS). As requirements change, or new
features become available, a new program can be loaded so as to provide a
migration path to upgrade the existing system.
FDM170
This is a Plug-In version for the 170 Series of Controllers and the R400/R800
Rack Series. The Main Data port is connected via the card edge connector to the
170 backplane while the Aux Data Port RJ45 is front accessible for combining
external data links in the polling stream.
For rack-mounted communications at the Traffic Maintenance Center, R400/R800
Series Racks can be populated with the FDM170 to complete the communications
system.
FDM2070
This is a Plug-In version for the 2070 Series of Controllers. The Main and
Auxiliary Data ports provide the same functionality as in the FDM170, plus one
of the 2070’s spare Serial Ports SP2 or SP4 (slot dependant) is also brought out to
the front panel. For rack-mounted communications at the Traffic Maintenance
Center, R400/R800 Series Racks would be populated with the FDM170 to
complete the communications system.
