The central control unit is a microcontroller based unit that is programmed to continually monitor the DCC commands transmitted from the command station via the track and to take action when an accessory command with a matching address is received.
The central control unit has an opto-isolated input for the track signals to protect the microcontroller from any high level track signals. The opto-isolation also provides protection for the command station. It also rectifies the signal to produce a positive square wave representing the data packet.
There are four outlet jacks on the central control unit circuit board. Each of these jacks connects to a slave
module which generally controls two accessories, making a total of up to eight accessories that can be controlled from a single central control unit.
The central control unit requires a power supply of 12 - 14 volts regulated and filtered direct current (V DC).
A programming switch is provided for use when setting the accessory decoder address range for the central control unit. The central control unit monitors eight accessory decoder addresses. A light emitting diode (LED) is also provided that is used to indicate the operation and modes of the central control unit.
The SD-001 Central Control Unit is used for decoding DCC commands and driving slave modules.
When a data packet is received that has a matching accessory address the central control unit decodes the the data contained in the packet and then carries out the command by sending an instruction to the connected slave module.