Series 16/18/160/180-Model C Maintenance Manual, GFZ-62755EN ...

8. TROUBLESHOOTING B–62755EN/018.11ALARM 90(REFERENCEPOSITION RETURN ISABNORMAL)ContentsReference position return was executed when the following condition isnot satisfied:The CNC received one rotation signal at least one time when the axis ismoving to the reference position at a speed higher than a speed equivalentto 128 pulses of position error amount(DGN300).Countermeasures(START)Check whether position gain is greater than 128 pulses(DGN 300) before or during reference position return.Position erroramount : 300128 ormoreRaise the speedNOYES(1) Next pageCheck feed rate command:PRM 1420 F : Rapid traverse rate (mm/min)PRM 1424 Manual rapid traverse rate (mm/min)PRM 1825 G : Servo loop gain (0.01sec–1)F5000/3Position error=Gdetection unit[µm/PLUSE]Detection unit : Move amount to a command pulse (usually 1µm)In metric machine, if the no. of digits below decimal point is 4 on theposition display screen, detection unit is 0.1 mm.Check rapid traverse override signals :ROV1 DGN 014.01014.0 (For TT series)ROV2 DGN 014.11014.1 (For TT series)PRM 1421 Fo rateROV1ROV20 00 11 01 1Override100%50%25%Fo rateCheck reference position return deceleration signalDEC1 DEC8 DGN 009.0 ∼ 009.7When reference position return is started from deceleration signal 0, feed ratebecomes FL rate.PRM 1425 FL rate334