Mitsubishi GX Configurator-PT, User Manual

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MELSEC-Q
9 POSITIONING CONTROL
9.1.4 Confirming the current value
Values showing the current value
The following address is used as value to show the position in the QD70.
This address (current feed value) is stored in the monitor data area, is used in
monitoring the current value display, etc.
Current feed value
•
This is the value stored in "Md. 1 Current feed value".
•
This value has an address established with a "machine OPR control" as a
reference, but the address can be changed by changing the current value
to a new value.
•
Update timing
QD70P4: 1ms QD70P8: 2ms
0 1
Current feed value
t
V
OP
20000
Current value is changed to 20000
by current value changing.
Address after current value
changing is stored.
10000
Md.1
to
Fig. 9.7 Current feed value
Restrictions
1) If the "current feed value" stored is used for control, an error of 1ms (for the
QD70P4) or 2ms (for the QD70P8) is produced at the update timing of the
current value.
2) The "current feed value" is controlled by a signed numerical value.
(Range: -2147483648 to 2147483647 pulse) Hence, continuation of counting
up will cause an overflow and continuation of counting down will cause an
underflow. Normal operation cannot be performed in an overflow or
underflow status. If there is a possibility of an overflow or underflow, set the
software stroke limit function valid. (Refer to "Section 11.4 Software stroke
limit function" for details.)
Monitoring the current value
The "current feed value" is stored in the following buffer memory address, and can
be read using a "DFRO (P) command" from the PLC CPU.
Buffer memory addresses
Axis 1 Axis 2 Axis 3 Axis 4 Axis 5 Axis 6 Axis 7 Axis 8
Md. 1 Current feed value
70
71 170
171 270
271 370
371 470
471 570
571 670
671 770
771
Example
Program in which the axis 1 current feed value is read to D104 and D105
<Read current feed value to D104 and D105>