Thanks
DiSEqC = Digital Satellite Equipment Control
EUTELSAT refined and finally specified the system under the name DiSEqC (Digital Satellite Equipment Control). DiSEqC is an open and unlicensed industrial standard available to anyone and is coordinated by EUTELSAT. DiSEqC™ is a trademark of EUTELSAT.
you can find documentation (protocol,hardware,....)about diseqc at www.eutelsat.com
only search the diseqc there.
i think you must use DC motor instead of a stepper motor.because they are low power and high cost.
best regards.