This function block may be used with the Cyclic Position function block to set the Cycle Zero position for the Internal Count and to empirically set the Cycle Length. The Set Cycle Zero and the Set Cycle Length functions may be separately Enabled to control their behavior.

Typically, an external sensor such as a photo-eye or a proximity switch is mounted on the machine and connected to the DIN2 input (Terminal E5 resetting the Cycle Zero position every cycle prevents any long-term accumulated error. Mechanical switches are NOT recommended; however, should one be used, a debouncing circuit may be required to ensure reliable operation.

Usually, the Length Enable feature is only used during initial commissioning of the application; however, should the relationship between the encoder and the machine indices change in any way (e.g., the encoder being physically relocated), resetting both the Zero position and Cycle Length will likely be required.

The normal commissioning procedure would be as follows:

1. Decide in which direction you would like to move the machine for calibration.
   • In the forward direction, the count will be increasing.
   • In the reverse direction, the count will be decreasing.
   
   
2. To prepare for the calibration, move the sensor target (mounted on the machine) to the side opposite selected calibration direction. If properly positioned, the target will pass the sensor shortly after you initiate motion.
   
   
3. Enable both the Enable and Length Enable parameters.
   
   
4. Move the target on the machine past the the external sensor connected to DIN2. On the first pass, the Internal Count is reset.
   
   
5. Continue to move the machine through one entire cycle (in the same direction!) When the target again passes the external sensor, the Cycle Length will be set.
   
   
6. At this point the initial calibration is complete.
   
   
7. Disable the Length Enable parameter and check the value of the Cycle Length in the associated ENC# Cyclic Position function block versus the expected value.
   
   
8. In most applications, leave the Enable parameter Enabled so the Cycle Zero is reset every cycle. If desired, you may Enable the Window Enable and set the Window Width to an appropriate value to restrict when the DIN2 input is acted upon.

• Available only in the dw2xx series products
• Requires library: Encoder Control (option -11)
• Requires: Dual Encoder
• Firmware versions 0x2015 and later

When Enabled, the rising-edge of the DIN2 input resets the Internal Count to zero.

When Enabled, the window feature prevents spurious resets of the Internal Count and Cycle Length by limiting the physical location where the calibrator function block looks for the DIN2 reset input. The window is centered on the current Zero position. Otherwise, any transition of the DIN2 input will cause a reset.

This parameter sets the overall width of the window feature as a percentage of the Cycle Length and is centered on the Zero position.

If Window Enable is Enabled, this parameter indicates how close the current position is to the Zero position (within the limits of the Window Width). An OK status is indicated when within the window while an Out of Window is indicated when outside of the window.

If Window Enable is Disabled, the status always indicates Out of Window.

When Enabled, the first rising-edge of the DIN2 input resets the Internal Count to zero while the second rising-edge of the DIN2 input moves the Internal Count to the Cycle Length defining the cycle.