Hello,

My issue is this. I am working on an a71 Makino horizontal machining center with Pro 5 software (windows based for the NC side) and the CNC side is Fanuc. Problem I am having is I cannot get the Y axis to reference with the scale unit turned off. The issues we were having is the machine was alarming out in the Y axis because of a faulty scale reading. I have replaced the scale cable and the scale itself. I have indicated the scale in per the specs and alignment procedure. The process for getting the scale to calibrate is to turn off Fanuc parameters for the scale unit. These parameters being 1815 bit 1, 1905 bit 6, 1936, 2024, 2085 and 2185. Also once axis is off the decal switch you are to turn off parameter 1815 bit 4 (APZ) from a 1 to a zero if necessary. This being the parameter that the encoder uses to determine when the machine has found home. In the procedure it tells you tells you to turn off the scale using these parameters, cycle power and then try referencing the axis using only the pulse coder. It says in the procedure that the axis being calibrated will alarm out in OT2 (hard over travel). It then says to back off the beyond the decal switch and reference again and it should find home. So.....two things here to note.

When the scale unit is on the machine powers up but goes into an alarm for 1829 parameter positional deviation. When the scale is turned off, the machine will not reference without the scale, at least not properly. I can teach a fake home position but it will NOT reference with scale unit off per the procedure. It has been suggested to me that the control board on the fanuc side may be bad but I just don't feel this is the case.

I guess my question would be, has anyone ever dealt with replacing scales before and do you have any suggestions as to what steps I should take?

Thanks in advance!