Mitsubishi Electric MELSEC-L LD75D, User Manual

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CHAPTER 12 CONTROL SUB FUNCTIONS
12
12.
6 Abs
olut
e Pos
ition
Res
tora
tion
F
unc
tion
(c) Calculation of positioning address and concept of absolute position detection
system
Use the following expression to calculate the positioning address.
(Positioning address) = (Movement amount per pulse)

(Number of output pulses) + (OP address)

Expression 1
(d) Concept for the unit of mm, inch or pulse
The range which satisfies Conditions 1 and 2 can be used as the positioning address of the absolute position
detection system.
The range which does not satisfy Conditions 1 and 2 cannot be used as the positioning address of the absolute
position detection system.
The concepts of the positioning addresses in mm, inch and pulse are identical, the following examples provide
those of the mm unit.
Ex.
1
• There are the following conditions to calculate the positioning address:
• Calculate the upper/lower limit values of the positioning address which can be specified from the output
pulse count using range in Condition 1 and the positioning address calculation expression (Expression 1).
• The upper/lower limit values of the positioning address calculated are within the range of Condition 2.

Movement amount per pulse: 0.1 (

m)

OP address: 0.0 (

m)

Feedback pulses = 8192 (pulse)

Lower limit value of positioning address (the number of negative pulses in Condition 1 is used for
calculation)
(Positioning address)
= (Movement amount per pulse)

(Number of output pulses) + (OP address)
= 0.1

(-268435456) + 0.0
= -26843545.6 (

m)

Upper limit value of positioning address (the number of positive pulses in Condition 1 is used for
calculation)
(Positioning address)
= (Movement amount per pulse)

(Number of output pulses) + (OP address)
= 0.1

268 0.0
= 26843545.5 (

m)
Hence, the positioning range [-26843545.6 to 26843545.5 (

m)] calculated in Condition 1 can be used in
the absolute position detection system.
Positioning outside of the range -26843545.6 to 26843545.5 (

m) cannot be used in the absolute position
detection system.
-214748364.8 214748364.7 26843545.5 -26843545.6 0
Unit: µm
OP
Unusable range in
absolute position
detection system
Unusable range in
absolute position
detection system Usable range in absolute position detection system