TTL Serial Servo Motors

TTL serial servos are commanded over a single-wire bus instead of a pulse train, so one controller can address several servos on the same three wires and read back position where the firmware supports it.

Mechanically these are the same servos as their PWM counterparts: same case, same geartrain, same output spline. What changes is the control board. The inspection sheet for a TTL build lists TTL as the command signal, and the pulse-width rows that remain in the sheet belong to the PWM version of the same servo — they are not the TTL protocol description.

Bit rate, node ID range and command set are not printed on the inspection sheet. Ask for the serial parameter set for the specific model before writing firmware.