Mitsubishi Electric MELSEC-L LD75D, User Manual

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CHAPTER 9 MAJOR POSITIONING CONTROL
9
9.
1 O
u
tline
o
f Major Pos
itioning
Cont
rols
9.1.4
Confirming the current value
(1) Values showing the current value
The following two types of addresses are used as values to show the position in the LD75.
These addresses ("current feed value" and "machine feed value") are stored in the monitor data area, and used
in monitoring the current value display, etc.
(a) Current feed value
• This is the value stored in "[Md.20] Current feed value".
• This value has an address established with a "machine OPR" as a reference, but the address can be
changed by changing the current value to a new value.
• This value is updated every 0.9ms.
(b) Machine feed value
• This is the value stored in "[Md.21] Machine feed value".
• This value always has an address established with a "machine OPR" as a reference. The address cannot
be changed, even if the current value is changed to a new value.
• This value is updated every 0.9ms.
The "current feed value" and "machine feed value" are used in monitoring the current value display, etc.
(2) Restrictions
A 0.9ms error will occur in the current value update timing when the stored "current feed value" is used in the
control. A 0.9ms error will occur in the current value update timing when the stored "machine feed value" is used
in the control.
0
1 to
Current feed value
t
V
OP
20000
Current value changed to
20000 with current value
changing instruction
0 1 to
Machine feed value
Address after the current
value is changed is stored
10000
10000
Address does not change even
after the current value is changed
Md.20
Md.21