joint 2 following error on 5i25-7i77

Following error means that the Z-axis has deviated by more than the allowed amount from the commanded position.

This could be caused by a number of things.

Has the machine ever worked?

To many reasons for that, we need much more information about the machine and wiring etc.
If this is a new retrofit, that is to be expected.
Be sure that the enable button on the Linuxcnc can dissable the drives before you engage in tuning the motors.
If that was a working machine and now you get that error, check if the drives are enabled and also check the Linuxcnc DRO if the numbers change when you turn the motors by hand, if that is possible.

This was written a while ago, could not post it due to power outage .