const int pinRelayA = 8;
const int pinRelayB = 9;
 
void setup()
{
   // initialize relay pins
   pinMode(pinRelayA, OUTPUT);
   pinMode(pinRelayB, OUTPUT);
 
   // preset relays to LOW
   digitalWrite(pinRelayA, LOW);
   digitalWrite(pinRelayB, LOW);
}
 
void loop()
{
   extendActuator();
   delay(20000);
   retractActuator();
   delay(20000);
   stopActuator();
   delay(5000);
}
 
//Set one relay one and the other off
//this will move extend the actuator
void extendActuator()
{
   digitalWrite(pinRelayB, LOW);
   delay(250);
   digitalWrite(pinRelayA, HIGH);
}
 
//Set one relay off and the other on 
//this will move retract the actuator 
void retractActuator()
{
   digitalWrite(pinRelayA, LOW);
   delay(250);
   digitalWrite(pinRelayB, HIGH);
}
 
//Set both relays off
//this will stop the actuator in a braking
void stopActuator()
{
   digitalWrite(pinRelayA, LOW);
   digitalWrite(pinRelayB, LOW);
}