9 - 17 
MELSEC-Q
 
9   MAJOR POSITIONING CONTROL 
 
 Restrictions 
 
(1)  A 3.5ms error will occur in the current value update timing when the stored 
"current feed value" is used in the control.  
A 56.8ms error will occur in the current value update timing when the stored 
"machine feed value" is used in the control. 
 
(2)  The "current feed value" and "machine feed value" may differ from the values 
set in "
Da.6
 Positioning address/movement amount" of the positioning data if 
the movement amount per pulse is not set to "1".  
 
 Monitoring the current value 
 
The "current feed value" and "machine feed value" are stored in the following 
buffer memory addresses, and can be read using a "DFRO (P) command" from 
the PLC CPU.  
 
Buffer memory addresses  
Axis 1  Axis 2  Axis 3  Axis 4 
Md.20
Current feed value 
800, 801  900, 900  1000, 1001  1100, 1101 
Md.21
Machine feed value 
802, 803  902, 903  1002, 1003  1102, 1103 
 
Example
Program in which the axis 1 current feed value is read to D104 and D105
 <Read current feed value to D104 and D105>