Speed and Position Synchronization with XPM_SSP, XPM_SSS, and XPM_SSSP

XEM CPU has a few options for synchronizing a sub-axis with a master. The axes being controlled must already be configured using the XG-PM software before using the synchronization function blocks.

Function Block Description in XG5000 Function
XPM_SSP Position synchronization Execute a step in the Position Data table of the slave axis after the master axis reached the defined position.
XPM_SSS Speed synchronization Control the speed of the slave axis according to the ratio setup with the master axis.
XPM_SSSP Positioning speed sync Control the speed of the slave axis according to the ratio setup with the master axis until the slave axis reaches the defined position.

XPM__SSP Details

XPM_SSP is used for position synchronization of a sub-axis.

  • A step in the position data table is executed when the master axis reaches synchronization position (MST_ADDR).

  • The axis that uses the XPM_SSP function block is considered the sub-axis.

Element Name Element Type Description
REQ Input Edge detected request to execute the function block
BASE Input Base number of the motion controller.Equal to 0 for built-in position control.
SLOT Input Slot number of the motion controller.Equal to 1 for built-in position control
AXIS Input Axis number to control.Set to 1 thru 6 for built-in axes. This can be a constant or variable.
STEP Input Step in the position table to execute when master axis reaches MST_ADDR position.
MST_AXIS Input Master axis number.For XEM this is 1~6 and must not be the axis executing the XPM_SSP.
MST_ADDR Input Master position to execute the position synchronization for the sub-axis.
DONE Output Status that function block is done.
STAT Output Current status of the function block.Non-zero numbers will be an error or warning.

XPM_SSS Details

XPM_SSS is used to control the operating speed between two axes at the set ratio.

  • The synchronization is done with the Master Ratio and Sub-axis Ratio.

  • If master ratio value is larger, then the sub-axis will move slower than the master.

  • If sub-axis ratio value is larger, then the sub-axis will move faster than the master.

  • The sub-axis will move in the same direction as the master axis if the ratio is positive.

  • The sub-axis will move in the opposite direction of the master axis if the ratio is negative.

Element Name Element Type Description
REQ Input Edge detected request to execute the function block
BASE Input Base number of the motion controller.Equal to 0 for built-in position control.
SLOT Input Slot number of the motion controller.Equal to 1 for built-in position control
AXIS Input Axis number to control.Set to 1 thru 6 for built-in axes. This can be a constant or variable.
MST_AXIS Input Master axis number.For XEM this is 1~6 and must not be the axis executing the XPM_SSS.
MST_RAT Input Master speed ratio value. Value can be between -32,768 thru 32767.
SLV_RAT Input Sub-axis speed ratio value can be between -32,768 thru 32767.
DONE Output Status that function block is done.
STAT Output Current status of the function block.Non-zero numbers will be an error or warning.

XPM_SSSP Details

XPM_SSSP is used to control the operating speed between two axes at the set ratio.

  • The sub-axis will stop when its position reaches the POS value.

  • The synchronization is done with the Master Ratio and Sub-axis Ratio.

  • If master ratio value is larger, then the sub-axis will move slower than the master.

  • If sub-axis ratio value is larger, then the sub-axis will move faster than the master.

  • The sub-axis will move in the same direction as the master axis if the ratio is positive.

  • The sub-axis will move in the opposite direction of the master axis if the ratio is negative.

Element Name Element Type Description
REQ Input Edge detected request to execute the function block
BASE Input Base number of the motion controller.Equal to 0 for built-in position control.
SLOT Input Slot number of the motion controller.Equal to 1 for built-in position control
AXIS Input Axis number to control.Set to 1 thru 6 for built-in axes. This can be a constant or variable.
MST_AXIS Input Master axis number.For XEM this is 1~6 and must not be the axis executing the XPM_SSS.
MST_RAT Input Master speed ratio value. Value can be between -32,768 thru 32767.
SLV_RAT Input Sub-axis speed ratio value. Value can be between -32,768 thru 32767.
POS Input Target position of the sub-axis.
DONE Output Status that function block is done.
STAT Output Current status of the function block.Non-zero numbers will be an error or warning.

  • These examples show control of Axis 1 by an XEM-DN32HP CPU.

  • Axis 1 is a LS Electric L7CA004U-AD connected to a linear actuator with a 5 mm pitch.

  • The L7C servo drive is configured to have 1000 pulses be one revolution of the motor.

Step Action
1

Open the XG5000 project for the application. Go to Tools menu èPosition Control to open XG-PM software.
2

Open the XG-PM project or connect to PLC and select ProjectèOpen from PLC.
3

Open the Parameter file in the Workspace for the axis that is being configured. This example shows Axis #1.

This parameter screen will open:
4

Configure the parameters of the Axis. This example shows Axis 1.
6

Save the project. Connect to the CPU and write the project to the CPU.

Note: If connecting XG5000 and XG-PM at the same time, make sure to connect XG5000 first. XG5000 will give error messages if it is connected last.

This example is Scan Program XPM_SSP_Example in the LP531_SynchronizationExample XG5000 project.

  • In this example Axis 1 is the master axis and Axis 2 is the sub-axis.

  • When the Run_Example variable is true, Axis 1 will do a speed control move to 1000 pulses/sec and Axis2 will execute an XPM_SSP function block.

  • Axis 2’s XPM_SSP is setup to execute step 1 of the position table when Axis 1’s position reaches 10000 pulses.

  • Home Axes before setting Run_Example to true.

XPM_SSP LD Code

Home_Axes Command:

Run_Example Command:

XPM_SSP Trend

This example is Scan Program XPM_SSS_Example in the LP531_SynchronizationExample XG5000 project.

  • In this example Axis 1 is the master axis and Axis 2 is the sub-axis.

  • When the Run_Example variable is true, Axis 1 will do a speed control move to 1000 pulses/sec and Axis2 will execute an XPM_SSS function block.

  • Axis 2’s XPM_SSS is setup to speed synchronize with Axis 1 at half of Axis 1’s speed.

XPM_SSS LD Code

Home_Axes Command:

Run_Example Command:

XG-PM Monitoring for XPM_SSS Example

This example is Scan Program XPM_SSSP_Example in the LP513_SynchronizationExample XG5000 project.

  • In this example Axis 1 is the master axis and Axis 2 is the sub-axis.

  • When the Run_Example variable is true, Axis 1 will do a speed control move to 1000 pulses/sec and Axis2 will execute an XPM_SSSP function block.

  • Axis 2’s XPM_SSSP is setup to speed synchronize with Axis 1 at half of Axis 1’s speed.

  • Axis 2 will stop after its position reaches 10000 pulses.

  • Execute Home_Axes command before Run_Example.

XPM_SSSP LD Code

Home_Axes Command:

Run_Example Command:

XG-PM Monitoring for XPM_SSSP Example

Trend Monitoring for XPM_SSSP Example

 

 

 

 

 

 

 

LP531