Mitsubishi Electronics QD75D, QD75P Appendix 10 MELSEC Explanation of positioning terms

Appendix - 68
MELSEC-Q
APPENDICES
Appendix 10 MELSEC Explanation of positioning terms
1-2 PHASE EXCITATION SYSTEM
This is one system for exciting each stepping
motor coil in a determined order. In this
system, one phase and two phases are
alternately excited.
Pulse input
A phase
A phase
B phase
B phase
2-PHASE EXCITATION SYSTEM
This is one system for exciting each stepping
motor coil in a determined order. In this
system, a current constantly flows to 2 phases
to carry out step feed.
Pulse input
B phase
A phase
A phase
B phase
2-PHASE PULSE
An A phase and B phase double pulse. There
is a phase difference between the two phases,
so that difference can be automatically added
and subtracted in the pulse count. The
standard phase difference is a 90ø electrical
angle.
If the B phase were to lag behind the A phase
in a forward run (B phase turns ON after the A
phase), the A phase would lag behind the B
phase in a reverse run (A phase turns ON after
the B phase). In this way the forward and
reverse run (addition and subtraction) can be
automatically carried out.
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90°
A phase
B phase
Pulse countForward run
(addition) Reverse run (subtraction)
2-SPEED TRAPEZOIDAL CONTROL
In this positioning control method, the
positioning pattern, positioning addresses ( P1,
P2), and positioning speeds (V1, V2) are se t in
the sequence program. Positioning is carried
out to positioning address P1 by issuing the 1st
positioning start command. When P1 is
reached, the positioning then automaticall y
changes to positioning at the V2 speed.
Speed
Positioning speed V1
Positioning speed V2
Time
Positioning address P2
Positioning address P1