Allen-Bradley Kinetix 5100 2198-E1004-ERS - Electronic Gear (E-Gear) Ratio

204 Rockwell Automation Publication 2198-UM004A-EN-P - October 2019
Chapter 10 Modes of Operation
Electronic Gear (E-Gear) Ratio
Electronic gear (E-Gear) ratio defines the relationship between PUU and
internal encoder counts. It is determined by a ratio between ID151 (P1.044) and
ID152 (P1.045). Normally, ID151 (P1.044) is set to the encoder resolution. For
example, if ID151 (P1.044) is set to 10000, ID151 (P1.044) is set to 16,777,216
with 24-bit encoder. If you move 10000 PUU in PR mode or received 10000
pulse in PT mode, it causes the motor rotate one revolution.
When the ratio is set to 1, then every one pulse from the command (controller)
corresponds to one pulse of the motor. However, a larger E-Gear ratio can create
a sharp corner of the profile and lead to a high jerk. To solve this problem, you can
apply S-curve acceleration/deceleration or low-pass filter to reduce the jerk.
For example:
The ball screw pitch is 3 mm, when using a 4 bit encoder, if the E-Gear ratio is set
to 16777216/3000, then the workpiece moves 1 µm per 1 pulse command.
E-Gear Status Gear Ratio Moving Distance per 1 Pulse Command
E-Gear is not applied
E-Gear is applied
Table 73 - Relevant Parameters
(1)
(1) Do not change the setting value in servo on state.
Parameter Name
ID151 (P1.044) GearRatioFollowerCountsN1
ID236 (P2.060) GearRatioFollowerCountsN2
ID237 (P2.061) GearRatioFollowerCountsN3
ID238 (P2.062) GearRatioFollowerCountsN4
ID152 (P1.045) GearRatioMasterCounts (denominator)
ID170 (P1.068) PositionCmdMovingFilterTime
Motor
Platform
Workpiece
Ball screw pitch:
3 mm = 3000 µm
1
=
1
1
1
(Unit:
)
rev
µm
pulse
µm
rev
pulse
=
=x
16777216
3000
16777216
3000
=
3000
16777216
1
(Unit: )
rev
µm
pulse
µm
rev
pulse
=
=x
16777216
3000
3000
16777216