For signal cables you want Shielded CY cables or like Clive says you can use twisted pair Cat5 but only use inside control panel not running to limits etc on machine as it's not really flexible enough. I tend to use Cat5 in box as theres less wires and one cable will provide for 2 drives.
Yes quite correct I should have said cat5 flexi as in the patch cable type. (although you can buy flexi by the roll). Clive