Thanks for the replies

Tribbles
Im not using the optos as i plan to make modular set up with a master board for the optos. Thank for spotting the mistakes, thought it was a funny looking diode :whistling:

The +5 is supplied from the input connector, Bottom left.

Irving

So is the Pic just earthing the 5v supply to the VREF making it 0v which means there is no holding current? I presume it would then revert back when a pulse is detected on the clock line?