Mitsubishi A1SD75M1, User Manual

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12 - 12
MELSEC-A
12 CONTROL AUXILIARY FUNCTIONS
(b) Zero point shift operation at the " Pr.49 Creep speed"
Creep speed
Zero point
Pr.46
Pr.49
Zero point
return direction
When the " Zero point
shift amount" is positive Pr.55
When the " Zero point
shift amount" is negative
Pr.55
Zero point
Near-point dog
Zero point
Machine zero point
return start
Fig. 12.8 Zero point shift operation at the creep speed
(4) Precautions during control
The following data are set after the zero point shift amount is complete.
•
Zero point return request flag ( Md.40 Status: b3)
•
Zero point return complete flag ( Md.40 Status: b4)
•
Md.29 Current feed value
•
Md.30 Machine feed value
•
Md.35 Axis operation status
•
Md.44 Movement amount after near-point dog ON (" Pr.55 Zero point shift
amount" is not added.)
(5) Setting the zero point shift function
To use the "zero point shift function", set the required details in the parameters
shown in the following table, and write them to the AD75.
When the parameters are set, the zero point shift function will be added to the
machine zero point return control. The set details are validated at the rising edge
(OFF ON) of the PLC READY signal (Y1D).
Setting item
Setting
value
Setting details
Factory-set
initial value
Pr.55
Zero point shift
amount
Set the shift amount during the zero point shift. 0
Pr.57
Speed designation
during zero point
shift
Select the speed during the zero point shift
0: Pr.48 Zero point return speed
1: Pr.49 Creep speed
0
* Refer to "5.2 List of parameters" for setting details.
REMARK
•
Parameters are set for each axis.
•
It is recommended that the parameters be set whenever possible with the AD75
software package. Execution by sequence program uses many sequence
programs and devices. The execution becomes complicated, and the scan times
will increase.