Sinumerik experts.

We are repairing a Gantry Baliu Laser with Sinumerik 810n from the nineties . The Y is a master slave drivers . TheCNC issues one analogue signals to the doubled Y drivers and ananalogue unit -Siemens A8.310 - is getting the encoders and creating the correction analog signalto both drivers to make the axes move inexact parallelizm . Allthat is fine but I dont have a clue how to adjust it after we repaired it . The error is too big and i guess the gantry is not parallelsoit gets phisically jammed.
Any info how to adjust? Does anyone has an english manual?
I am realy stuck here thanks for helping out.