The SD-003 two aspect signal slave module is used to operate signals that are fitted with light emitting diodes (LED) for lamps. It connects directly to the central control unit (SD-001).
When the central control unit receives a command it decodes it and send a signal to the SD-003 slave unit which then changes the signal from red to green and vice versa, depending on the command sent.
Up to four of these slave units can be connected to a central control unit.
The two aspect signal slave module can switch two signals in response to the data sent from the central control unit. One central control unit and four two aspect signal slave modules can control a total of eight signals.
The SD-003 two aspect signal slave module supplies the correct voltage and current directly to the LEDs. No separate resistors are needed.
The two aspect signal slave module obtains power to drive the LEDs from the central control unit, no separate power supply is required.
The two aspect signal slave module uses two accessory decoder addresses, one for each signal.
When a command to change the aspect of a signal is sent from the comamnd station, the central control unit receives the command via the track bus. When a command is received the central control unit decodes the command data packet to determine the accessory address and if a match is found the central control unit sends a signal to the slave unit. The two aspect signal slave unit then sends a data signal to the track signal and the lights change from red to green or from green to red depending on the command.
If an address match is not found the command is ignored and no data signal is sent to the slave unit and the signal does not change.