Servo enable signal

HiI am in the process of upgrading my CNC table to Clearpath Servos I am  using a Mesa 7I76E board with Linuxcnc software for the controller.  The board shows connecters for each axis outputs with the pins labeled.  Each connecter has ground and +5 volt pins which I assume is for the enable for the axis servo signal.The question I have is the enable signal remove when the power button on the screen off/out.Or is there another signal used to enable/dis-able the servos Thanks for your timeTom       

I have since been told to use the field 24 volts to enable the servos.
But the question about the signal for enable on/off is still there.

The behaviour of the enable output signal is dependent on how is connected in the hal file

Typically it would be connected to say joint.0.amp-enable-out which will go false when
power off or estop are true
 

thanks for the reply

have fun
Tom