Endat Encoder Position error

Ask Questions Mechatronics & Motion
1

Drive Used : 8BVI0055HWD0.000-1
Motor used : 8LSA46.DB030S100-3 (Compatible for Inductive EnDat encoders)
Endat Encoder used : 8BAC0120.001-2 (Used with the single turn configuration ,no battery)

For our application we have used the motor with the planetary gearbox with GR 1:24(24 motor revolution for 1 output revolution).
The Axis is configured as periodic rotary with period 360 (MpAxisBasic Axis ).This axis is used as CNC axis With MpCnc4Axis Block. Homing procedure is used for axis homing (Since endat encoder is used in single turn mode position feed back is available).

For a machine cycle motor is running for around 60 turns CW and 60 turns CCW.
After running few machine cycles once the once the machine is powered off and again powered on the the position feedback of the encoder is changed (the position shift of the encoder is around 120 deg at the Output side).This issue occurs after powering off and then powering on the machine.

Any clue is welcome.

Thank you for your help.

Encoder1
Encoder1884Ă—537 60.9 KB

Mot1
Mot1880Ă—422 48.5 KB

2

It is not clear what homing mode you have used.

The 8LSA46.DB030S100-3 has a multiturn endat 2.2 encoder without the need for battery.

Normally you would use homing mode mcHOMING_ABSOLUTE_CORRECTION or mcHOMING_RESTORE_POSITION, but for defining the offset or value of remanent variable, you will need another homing mode and procedure.

3

Got the answer, since it is a multi turn encoder after exceeding the 4096 rotation once the drive is powered off and on the encoder is taking the overflow value. So we are getting the unexpected encoder value.

4

If the movement range of this axis is limited to 4096 revolutions and you use a gearbox of i=16 or i = 32, then mcHOMING_ABSOLUTE_CORRECTION should actually be able to correct this.

5

we are using 1:24 GR and the our axis movement is exceeding 4096 revolution. So we are getting the encoder position shift.

6

Here is the Decision Making Picture for Homing from AS-Help.

image
image1116Ă—892 66.9 KB

Consider the limitations of “Restore Position” or change Hardware.

Greetings
Michael