8 - 4
MELSEC-Q
8 OPR CONTROL
8.2 Machine OPR8.2.1 Outline of the machine OPR operation
Important
Use the OPR retry function when the OP position is not always in the sa me
direction from the workpiece operation area (when the OP is not set near th e upper
or lower limit of the machine).
The machine OPR may not complete unless the O PR retry function is used.

Machine OPR operation

In a machine OPR, a machine OP is established.
None of the address information stored in the QD75, PLC CPU, or servo is use d at this
time. The position mechanically established after the machine OPR is regarded as the
"OP" to be the starting point for positioning control.
The method for establishing an "OP" by a machine OPR differs according to the method
set in " Pr.43 OPR method".
The following shows the operation when starting a machine OPR.
1) The machine OPR is started.
2) The operation starts according to the speed and direction set in the OPR parameters
(Pr.43 to Pr.57 ).
3) The "OP" is established by the method set in " Pr.43 OPR method", and the
machine stops. (Refer to Sections 8.2.2 to 8.2.8)
4)
If "a" is set as " Pr.45 OP address", "a" will be stored as the current position in the
"Md.20 Current feed value" and " Md.21 Machine feed value" which are
monitoring the position.
5) The machine OPR is completed.
The " Pr.45 OP address" is a fixed value set by the user.
M
OP
Near-point dog
Machine OPR
Fig. 8.1 Example of a machine OPR