SC8 - Servo Controller

The SC8 is a DCC compatible accessory decoder capable of driving eight servo motors . It has eight inputs for local control and 8 routes and a serial bus.

MSRP - 54.95 USD
Manual in PDF format

Board size: ~ 2.6" X 2.4”

• DCC compatible accessory decoder
• Controls 8 servos
• "Power Save" greatly reduces current requirements
• Programmable position, range and speed of servos
• “Speed_to_Position”
• Inputs for local control of servos
• Remote controlled routes for turnouts
• Digitrax LocoNet® compatible serial bus
• DCC gateway to serial bus

There are two basic modes of operation that determine how the servo is used.

The first basic configuration is moving servos to two positions.
Mode 1 - The servo outputs can be used for turnout control. There is a separate address for each output so they can be controlled individually. There are a total of eight switch addresses. In this mode a servo could also be used for crossing gates.

The second basic configuration is for moving servos to three positions.
Mode 2 - The servo outputs can be used for semaphore control. There are a total of 24 switch addresses. In this mode three addresses are used to control each servo, address A(throw) will command the servo to one end, address A+1(throw) will command it to the center and address A+2(throw) will command it to the other end.

Servos can easily draw 2 or 3 times the current of a Tortoise™. "Power Save" is a default option that essentially allows the SC8 to remove operating power from the servo when it is not moving. Since turnouts are not operated continually this can 'save' a lot of power.

“Speed_to_Position” is an optional behavior that allows the throttle to variably control the position of the servo (only outputs 1 to 4). Just as the throttle can be used to change an engine’s speed, so can it be used to control the position of a servo. The throttle speed step must be set to 128.

Two types of route control are supported. The remote controlled routes are controlled from the throttle just like a single switch is, except that multiple switches may be activated. The local routes are activated by using the inputs. Routes are configured by programming the respective CVs as to which outputs are selected in the route and the output state.

The SC8 is not fully compatible with the Atlas, Backmann or MRC (except Prodigy Advance) DCC systems because they do not support accessory commands or can not program the number of CVs in the SC8.