Mitsubishi Electric MELSEC-F Series - Page 63

7 Buffer Memory
7.3 Positioning Parameters
57
FX3U-1PG User's Manual
1
Introduction
2
Specification
3
System Configuration
4
Installation
5
Wiring
6
Before Starting Positioning Operation
7
Buffer Memory
8
Manual Control
9
Positioning Control
10
Program Example
Concept of mechanical system of units
When operation parameter BFM#3 (b1, b0) or BFM#37 (b1, b0) (system of units) is set to "(0, 1)", "(1, 0)" or
"(1, 1)", the mechanical system of units ("μm", "mdeg", "10
-4
inch") is selected. At this time, there is no
positioning parameter to select any one among "μm", "mdeg", "10
-4
inch". However, because all of the
positioning parameters (extension positioning parameters) as well as the positioning data and the speed data
used in the positioning program adopt the same unit, the same pulse output is acquired without regard to the
unit as long as the set value is equivalent.
Setting example
Condition
When you set values in "μm"
In a positioning operation with travel distance of 100 [μm] and operation speed of 6 [cm/min], the following
pulse output is given.
Generated pulse quantity = Travel distance ÷ Feed rate × Pulse rate
= 100 [μm] ÷ 100 [μm/REV] × 4,000 [PLS/REV]
= 4,000 [PLS]
Pulse frequency = Operation speed
*1
÷ Feed rate
*1
× Pulse rate
= 6 [cm/min] × 10
4
÷ 60 ÷ 100 [μm/REV] × 4,000 [PLS/REV]
= 40,000 [Hz]
*1. The unit is aligned during calculation. 1 cm = 10
4
μm, 1 min = 60 s.
When you set values in "mdeg"
In a positioning operation with travel distance of 100 [mdeg] and operation speed of 6 [10 deg/min], the
following pulse output is given.
Generated pulse quantity = Travel distance ÷ Feed rate × Pulse rate
= 100 [mdeg] ÷ 100 [mdeg/REV] × 4,000 [PLS/REV]
= 4,000 [PLS]
Pulse frequency = Operation speed
*2
÷ Feed rate
*2
× Pulse rate
= 6 [10deg/min] × 10
4
÷ 60 ÷ 100 [mdeg/REV] × 4,000 [PLS/REV]
= 40,000 [Hz]
*2. The unit is aligned during calculation. 1 deg = 10
3
mdeg, 1 min = 60 s.
When you set values in "10
-4
inch"
In a positioning operation with travel distance of 100 [× 10
-4
inch] and operation speed of 6 [inch/min], the
following pulse output is given.
Generated pulse quantity = Travel distance ÷ Feed rate × Pulse rate
= 100 [× 10
-4
inch] ÷ 100 [× 10
-4
inch/REV] × 4,000 [PLS/REV]
= 4,000 [PLS]
Pulse frequency = Operation speed
*3
÷ Feed rate × Pulse rate
= 6 [inch/min] × 10
4
÷ 60 ÷ 100 [× 10
-4
inch/REV] × 4,000 [PLS/REV]
= 40,000 [Hz]
*3. The unit is aligned during calculation. 1 min = 60 s.
Setting item Setting value Remarks
Pulse rate
(BFM#0 or BFM#34, #33)
4,000 [PLS/REV]
Feed rate
(BFM#2, #1 or BFM#36, #35)
100 [μm/REV, mdeg/REV, 10
-1
minch/REV]
Position data multiplier
[BFM#3 (b5, b4) or BFM#37 (b5, b4)]
0, 0
(b5=0, b4=0)
The travel distance is regarded as "μm",
"mdeg" or "10
-4
inch".
Electronic gear in servo amplifier
(Setting of the servo amplifier side)
1/1