Set Unit Scaling and Modulo

Prior to downloading, the Virtual Axis and AKD2G EtherNet/IP and WorkBench Unit Scaling and Modulo must be set.

Axis 1 Rotary Virtual Axis and AKD2G EtherNet/IP and WorkBench Unit Scaling


  • On the AKD2G-SPI axis, Modulo is only necessary when using a Rotary axis.

Set WorkBench Units

In the Studio 5000 Sample project, Axis 1 is configured as a Virtual Axis in the MotionGroup under the name Axis1_Rotary.

The Units are in millidegrees with a:

  • Conversion Constant of 1.0 (where 360000 = 360 degrees).
  • Position Unwind of 360000.

This is correlated in the Axis 1 Units and EtherNet/IP Scaling in WorkBench.

The Sample project and drive setup assumes Axis 1 is a direct drive rotary where the application units are in degrees.

Setting EtherNet/IP Units Scaling

For WorkBench Units to align with EtherNet/IP units (and the Virtual Axis) it is necessary to scale the ratio input and ratio output for position, velocity, and acceleration units.

In WorkBench, navigate to Device Settings > Communications > EtherNet/IP > Axis 1 > Scaling tab.

The scaling is:

  • Ratio Input: 360000 (EIP counts).
  • Ratio Output: 1 (motor rev).

This facilitates scaling for the Real Axis in the drive to follow the Virtual Axis’ trajectory when a Motion Instruction (i.e., MAJ) is used.

Example:

  • Speed is set to 360000 or 360 deg/s.
  • Accel/Decel are set to 60000 or 60 deg/s^2.

Setting Modulo


  • On the AKD2G-SPI axis, Modulo is only necessary when using a Rotary axis.

Since Axis 1 is setup as Rotary and the Virtual Axis has a Position Unwind of 360000 (mdeg), it is very important to:

  • Enable the Modulo.
  • Set the range in the AKD2G-SPI for Axis 1 so the axis never exceeds the range of the Position Unwind of the Virtual Axis.

screen capture of the Modulo view in WorkBench

Axis 2 Linear Virtual Axis and AKD2G EtherNet/IP and WorkBench Unit Scaling

In the sample project, a second virtual axis was created in the Motion Group in Studio 5000 named Axis2_Linear to demonstrate the case of a linear axis in the application.

Units are assumed to be millimeters and a conversion constant of 1.0 Feedback Counts/1.0 mm. Since the Virtual Axis is declared with a Linear Positioning Mode the Position Unwind is grayed out, making it unnecessary to enable Modulo in Axis 2 of the AKD2G-SPI.

In the Sample project, a second Virtual Axis named Axis2_Linear, was created in the MotionGroup in order to demonstrate the case of a linear axis in the application.

Units are assumed to be millimeters and a Conversion Constant of 1.

The ballscrew actuator used in creating and testing the Sample project uses the following mechanics:

  • 5 mm ballscrew with a 3.14 to 1 gear reducer

  • WorkBench Units were set normally to model the mechanics

  • Click the More button to view the calculated PIN and POUT for WorkBench Units (i.e., PIN = 250 and POUT = 157).

Note the Ratio Input and Ratio Output under the Scaling view (Communication > EtherNet/IP > Axis2 > Scaling tab).

  • Ratio Input: 250 x 1000 (to handle the integer to floating point scaling).
  • Ratio Output: 157.

This facilitates scaling for the Real Axis in the drive to follow the Virtual Axis’ trajectory when a Motion Instruction (i.e., MAJ) is used.

Example:

  • Speed is set to 10000 (equivalent to 10 mm/s).
  • Accel/Decel are set to 60000 (equivalent to 60 mm/s^2).