Okay, I went to ports and pins, Pin set up and checked the box to enable port 1. Moved to Input signals, Found E stop box and changed it, Clicked apply and okay. Rechecked and it had changed back. repeated steps half a doz times with the same result
I did take a reading anyway but no change except in G0 the reading is 0.6 MV instead of 0.4 of g1