Mitsubishi QD75M1, User Manual

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8 - 4
MELSEC-Q
8 OPR CONTROL
8.2 Machine OPR
8.2.1 Outline of the machine OPR operation
Important
Use the OPR retry function when the OP position is not always in the same
direction from the workpiece operation area (when the OP is not set near the upper
or lower limit of the machine).
The machine OPR may not complete unless the OPR retry function is used.
Machine OPR operation
In a machine OPR, a near-point dog and zero signal are used to establish a machine
OP.
None of the address information stored in the QD75, PLC CPU, or servo is used 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 basic "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", 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