8 OPR CONTROL

8.2 Machine OPR

8.2.1Outline of the machine OPR operation Important

MELSEC-Q

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 machine OP is established.

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 machine OPR.

1)The machine OPR is started.

The operation starts according to the speed and direction set in the OPR parameters

2)( 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)

 

 

 

 

 

 

 

 

If "a" is set as "

 

OP address", "a" will be stored as the current position in the

 

Pr.45

4) " 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

Machine OPR

Near-point dog

Fig. 8.1 Example of a machine OPR

8 - 4

Page 282
Image 282
Mitsubishi Electronics QD75P Machine OPR Outline of the machine OPR operation Important, Machine OPR operation, Pr.45