Turnout and Signal
control from a CTC Panel
General
Operation:
This scheme provides for turnout and signal control from
a dispatcher using a Centralized Traffic Control (CTC)
panel with Team Digital SRC16(s), SIC24AD(s) and DBD22(s)
in a DCC system. Turnout control is also available via a
throttle. It also demonstrates the concept of an
accessory bus.
An accessory bus also called serial bus is defined as an
independent serial bus separate from the throttle bus. It
provides a way for accessory devices to communicate with
each other. This can provide several advantages for a DCC
system. An accessory bus can expand the selection of
devices available for applications and can aid in trouble
shooting.
The SRC16 is an accessory decoder and can be powered from
DCC track power. Since it can be controlled via DCC
commands it's gateway feature provides a very convenient
way to pass turnout (switch) commands to the accessory
bus. This allows DCC turnout commands to control devices
connected to the accessory bus. Thus, turnouts can be
controlled either from the throttle or from the
dispatcher.
Turnouts:
SRC16(s) are used to control turnouts and optionally
indicate turnout status. They can drive stall motor type
switch machine with 5 volts or with a higher voltage
using MotoDs. With MotoDs the SRC16 control up to 16
stall motors.
Block Status:
DBD22(s) are connected to the SIC24(s) to provide block
status.
The SIC24(s) send the block status information to the CTC
panel for dispatcher use.
Signaling:
SIC24AD(s) are used to drive the signal aspects. The
specific aspect to light is determined by the dispatcher
using the CTC panel. In this application the SIC24 is
configured as a general input/output device. The SIC24
has 24 output to drive up to 24 LEDs or eight 3 aspect
signals.
The accessory bus greatly simplifies wiring because the
SIC24s can be located around the layout near the signal
aspects they are driving. This means the DBD22s will be
near the blocks they are detecting.
CTC Panel:
The CTC panel is depicted on a computer screen using
software like JMRI. It allows the dispatcher to control
turnouts and signals. The panel also shows block
occupancy information.
The computer is connected to the accessory bus via a USB
cable and a LocoBuffer USB. The accessory bus is
compatible with Digitrax's LocoNet® so the computer
software must be configured for a LocoNet® interface.
Power:
The SRC16(s) and SIC24AD(s) may be powered from a
dedicated power supply or the track. Using the rail sync
lines in a separate accessory bus provides easy power
connections. DBD22(s) are powered from the SIC24(s).
Note: SIC24 is
sometimes used to refer to both the original SIC24 and
the new SIC24AD. The original SIC24 can NOT be powered from the track.
DCC system with dispatcher control
