[Leha_Blin]

Dear colleagues!

I have CNC milling machine with Fanuc 0iMC and Heidenhain linear scales.
When turning on the machine I try to carry out reference point search. This searc is ok with Y axis. But for X and Z axis machine stops at the same point with the message “090 Reference return incomplete”.
Do you have any ideas about this?

[PinMan]

The reference position return cannot be performed normally because the reference position return start point is too close to the reference position or the speed is too slow. Separate the start point far enough from the reference position, or specify a sufficiently fast speed for reference position return. Check the program contents.

With Fanuc controls, always make sure that the axis moves at least 1 nominal inch before reaching the home position.

[f-bu]

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

[Leha_Blin]

PinMan: Do you mean that I should relocate home position?
f-bu: I 'm not sure about the number of reference marks. Perhaps only one. This same direction is like from the middle of stroke range to home position or from location between reference mark and home position to middle of stroke range? I mean from the outside of small segment between ref.mark and home or from inside?
1428 - increasing of this parameter only shortens the time of error appearing. It stops in the same position.

If the sequence of actions you suggested will be successful should I do these operations all the time at machine power on?

[f-bu]

It is really very rare to have ref. marks every 50 mm, but it is trouble-free in case of incremental scales.
I could not understand if you managed to find the home with the procedure first passing in jog, then ref mode.
In fact, there is an option, that use absolute pulsecoder of the motor (if exist) and stores the approximate zero position. Will post the name when find it, maybe it exist on your control.

[f-bu]

1.4.4 Tentative Absolute Coordinate Setting

In a full–closed system with a built–in absolute position detector (serial pulse coder) and incremental linear scale, a coordinate system is set up, using absolute position data received from the built–in absolute position detector when the power is switched on. After this, position control is carried out using the linear scale incremental data. Because the machine position obtained immediately after the power is switched on is tentative, obtaining the accurate machine position requires making a manual
reference position return.
Even before a reference position return is made, using this function enables a stroke limit, although the machine position obtained when the power is switched on is approximate.
Note that this function is not intended to use an incremental linear scale as an absolute position detector.
This function is an option.

(attached)

Fig. 1.4.4 System using tentative absolute coordinate system setting

Parameter

#7 #6 #5 #4 #3 #2 #1 #0
1801 INA

[Data type] Bit
1801#3 INA Specifies whether to perform absolute position communication for re–setting up the machine position at a reset after a servo alarm other than alarm 413 (LSI overflow), 416, 445, 446, or 447 (broken–wire alarm) occurs in a system that uses an absolute position detector, as follows:
0 : To perform.
1 : Not to perform.

NOTE
1 If INA = 0 in a system that uses tentative absolute coordinate system setting, the machine position is approximate after a servo alarm other than 413, 416, 445, 446, or 447 is reset, because it has been re–set up using data received from the built–in absolute position coder.
2 When a reset is performed after a servo alarm 413, 416, 445, 446, or 447 occurs, absolute position communication for re–setting up the machine position always takes place.

#7 #6 #5 #4 #3 #2 #1 #0
1815 APCx OPTx

[Data type] Bit axis
#1 OPTx Specifies whether to use a separate position detector, as follows:
0 : Not to use.
1 : To use.
#5 APCx Specifies whether to use a absolute position detector, as follows:
0 : Not to use.
1 : To use.

NOTE
1 When using tentative absolute coordinate system setting, set both OPTx and APCx to 1.
2After setting any of these parameters, turn the power off then on again so that the setting will take effect.

1874 = Flexible feed gear numerator for built–in position detector
1875 = Flexible feed gear denominator for built–in position detector

[Data type] Word axis
[Valid data range] 1 to 32,767
Specifies a flexible feed gear for a built–in position detector for each axis when using tentative coordinate system setting, according to the following expression:

(NO.1874/NO.1875)=(Number of position feedback pulses per motor revolution)/(1,000,000)

NOTE
1 These parameters can be used also in a system that uses the Inductosyn.
2 After setting any of these parameters, turn the power off then on again so that the setting will take effect.

#7 #6 #5 #4 #3 #2 #1 #0
2011 XIAx

[Data type] Bit axis
#7 IN Specifies whether to enable tentative absolute coordinate system setting, as follows:
0 : To disable.
1 : To enable.

NOTE
Using tentative absolute coordinate system setting requires setting bit 1 (OPTx) of parameter No. 1815, bit 5 (APCx) of parameter No. 1815, parameter No. 1874, and parameter No. 1875.

[Spiker604]

If you have had the motors off, or have moved the decel dogs for the x & z axis, the marker pulses for the motors may be too close to the flaaing edge of the decel dog. this can be fixed by either moving the decel gog slightly or disconnecting the motor from the balscrew right at the coupling and giving it a half turn. give this a try, of course you will then have to adjust your fine home parameter.