There are too many questions, Lexa.
I think you have incremental scales. how many reference marks they have - only one or many at each 50 mm?
Try after power on to pass in jog mode trough reference mark, in the same direction as 'home' mode do. Then go back and try again in zero return mode. If fail with 090, check parameter 1428&1821 (1428-Скорость подачи при возврате в референтную позицию, 1821-Емкость референтного счетчика для каждой оси)
If the scales are type C(distance coded), there are much more parameters to check.
regards,
Fedia