12CONTROL SUB FUNCTIONS

[4]Precautions during software stroke limit check

MELSEC-Q

(1)A machine OPR must be executed beforehand for the "software stroke limit function" to function properly.

(2)During interpolation control, a stroke limit check is carried out for the every current value of both the reference axis and the interpolation axis. Every axis will not start if an error occurs, even if it only occurs in one axis.

(3) During circular interpolation control, the "

Pr.12

Software stroke limit upper

limit value"/"

Pr.13

Software stroke limit lower limit value" may be

exceeded.

In this case, a deceleration stop will not be carried out even if the stroke limit is exceeded. Always install an external limit switch if there is a possibility the stroke limit will be exceeded.

Example

Axis 1

 

Deceleration stop not carried out

Axis 1 stroke limit

 

Arc address ( Da. 7 )

Starting address

End point address ( Da. 6 )

 

Axis 2

The software stroke limit check is carried out for the following addresses during circular interpolation control. (Note that " Da. 7 Arc address" is carried out only for circular interpolation control with sub point designation.

Current value/end point address ( Da. 6 )/arc address ( )

(4)If an error is detected during continuous path control, the axis stops immediately on completion of execution of the positioning data located right before the positioning data in error.

Example

• If the positioning address of positioning data No. 13 is outside the software stroke limit range, the operation immediately stops after positioning data No. 12 has been executed.

Positioning data

Immediate stop at error detection

No.10

No.11

No.12

No.13

 

 

 

 

Md. 26

 

 

Axis operation status

Controlling position

Error occurring

No.10

P11

No.11

P11

No.12

P11

No.13

P11

No.14

P01

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Mitsubishi Electronics QD75D Precautions during software stroke limit check, Software stroke limit upper Limit value