I just got a TB6600 going. I connected the three negative pins and the enable plus pin to the ground pin on the Arduino. The direction plus pin must be changed when the pulse pin is low. I use a loop to set the pulse pin high, delay, set the plus pin low, delay.
void turn(int steps)
{
int i;
for (i=0; i<steps; i++)
{
digitalWrite(pin_pulse, HIGH);
delay(1);
digitalWrite(pin_pulse, LOW);
delay(1);
}