TC12 Installation, Commissioning & Maintenance Handbook
Digital Output Rack
The Digital output rack contains one Instation rack Power Supply Card and
between one and sixteen Digital Output boards, each capable of driving 64 LEDs
at up to 30 V 25 mA. There are two variants of Digital Output board, one sources
current and the other sinks current. The system could be used for any application
requiring digital output, not just wallmap driving.
Instation Test Set
The Instation Test Set (ITS) is housed in an attaché case, and connects to either
the Modem PCBs or the OTU PCBs. It contains a PC, a modified ITU modem
board, an ITS logic board and two power supplies. One power supply is the same
unit as on the PSU board in the ITU rack and is used to power both the boards,
whilst the other is the PC PSU. The ITS provides for connection to the Modem or
OTU board as well as use as a handset.
Outstation Test Set
The Outstation test set is a portable unit housed in a small grey metal case. It
requires a mains supply for operation and two cable forms with which to interface
with the OTU being tested.
Freestanding Outstation
The freestanding outstation is a rack that can be bolted into any Traffic Controller.
It contains a Power Supply, an OTU PCB and up to four detector PCBs. Two
connectors allow the OTU inputs and outputs to be wired up to the controller and
or detector cards, and the OTU is delivered with a cable for this purpose. The
outstation can also provide an LMU facility, and a connector allows current and
voltage monitoring transformers to be attached for this purpose. There is a pair of
test jacks on the board to allow connection to the Instation test set to monitor
communications data and measure signal levels.
Figure 1 and Figure 2 show diagrams of example system connections.
Integral OTU
The integral OTU is a printed circuit card that can be installed in a T400 or ST800
Traffic Controller. It is a version of the T400 Ancillary processor with suitable
firmware to configure it to be an OTU. A single 40-way ribbon cable connector
supplies communication to the controller and all power. A 60 way ribbon cable
connector is fitted for connection to current and voltage monitoring transformers
for use as an LMU. There is no provision for detector inputs - the controller
supplies all detector information.
Connection to the line is via a captive lead terminated in a 6-way BT plug.
There is a pair of test jacks on the board to allow connection to the Instation test
set to monitor communications data and measure signal levels.
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