Yaskawa MP2200 Machine Controller - Manual (Page 402)

7 Absolute Position Detection
7.3.2 Infinite Length Axis
7-18
7.3.2 Infinite Length Axis
( 1 ) Overview
Infinite length positioning is a function that automatically resets the machine position, program
position (absolute values in the program coordinate system), and current position at regular intervals
according to the Maximum Value of Rotary Counter (POSMAX) (fixed parameter 10). The function
can be used for repeated positioning in one direction.
Unfortunately, the maximum multiturn data is as follows, at which point the multiturn data is reset to
0.
• Σ Series: ±99999
• Σ -II/III Series infinite length axis: 0 to 65534 (Set with Pn205)
When system power is turned ON therefore, the MP2200/MP2300 position may not be the same
before and after power is turned ON. This problem can be resolved using one of the following two
methods.
[ a ] Simple Absolute Infinite Length Position Control
With this method, ladder program to manage the absolute infinite length axis position is not required.
The coordinate system is established simply by setting the Zero Point Offset (OL††48) when
setting the zero point after turning ON the power supply or restarting communication.
[ b ] Absolute Infinite Length Position Control
With this method, ladder program to manage the absolute infinite length axis position is required.
The coordinate system is established by turning ON the Infinite Length Axis Position Information
LOAD bit (OB††007).
( 2 ) Managing Positioning with the Simple Absolute Infinite Length Position Control Function
The simple absolute infinite length position control is used to manage the position of an infinite
length axes based on the assumption that the number of possible turns from the encoder is an integral
multiple of the number of encoder turns corresponding to the reset frequency in reference units. With
this method, ladder program to manage the infinite length position is not required.
This function can be used when the following conditions are met.
• The Σ -II or Σ -III Series is used.
• The following equation is satisfied:
(Maximum number of absolute encoder turns +1) / Reset number of turns = An integer
(remainder = 0)
[ a ] Setting the Zero Point
Set the desired position in OL††48 and execute the Zero Point Setting (ZSET) motion command.
The position will be set as the current position of the machine coordinate system.
POSMAX
0