Emerson EZMotion, User Manual

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EZMotion User/Programming Guide
www.controltechniques.com Revision: A8
8.7.4 Gearing View
Figure 143: Gearing View
The following parameters are used to configure Gearing motion:
Use Scale Check Box
Select this check box (Gear.UseScaleEnable) to enable the Scaling feature and disable Gear Ratio. Scaling allows the user to use
irrational ratios such as 1.0/7.0 that were not possible with the single parameter ratio (Gear.Ratio). Scaling is defined as follows:
Gear Ratio
Gearing is used to fix the motion of the motor to the motion of the master axis signal at a specified ratio. This is commonly called
“electronic line shafting” or “electronic gearing”. To gear the motor to the master axis, a ratio must be specified as a relationship
between follower distance units and master distance units. The ratio is as follows:
The ratio (Gear.Ratio) is defined as the number of follower distance units to move the motor per distance unit of travel. The gear ratio
can be positive or negative and is a signed 32-bit parameter. The resolution of the parameter is determined by the number of
decimal places configured for the Master Velocity Units on the Master Units Setup view.
By default, gearing does not use acceleration or deceleration ramps with respect to the master encoder. This means that once
gearing is activated, peak torque is available to try to achieve the specified gear ratio. Therefore, if the master axis is already in
motion when gearing is activated, the control loop will attempt to accelerate the motor to the programmed ratio within one update
(800µsec < update rate <1600 µsec). Analogously, when gearing is deactivated, the motor will use peak torque to bring the motor to
a stop without a deceleration ramp.
Direction
Bidirectional
The follower will follow both the plus and minus master axis command at the specified ratio.
ComMinus
The follower will follow only the minus master axis command.
ComPlus
The follower will follow only the plus master axis command.
Scaling =
Gear.ScaleNumerator (User Units)
Gear.ScaleDenominator (Master Units)
Gear Ratio =
# of Follower Distance Units
1 Master Distance Unit