Mitsubishi Electronics QD75P, QD75D user manual Appendix 10 Melsec Explanation of positioning terms

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	90°
system, one phase and two phases are
alternately excited.

MELSEC-Q

A phase

B phase

Pulse input

A phase

B phase

A 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

A phase

B phase

A phase

B phase

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Forward run	Reverse run	Pulse count
(addition)	(subtraction)

2-SPEED TRAPEZOIDAL CONTROL

In this positioning control method, the positioning pattern, positioning addresses (P1, P2), and positioning speeds (V1, V2) are set 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 automatically changes to positioning at the V2 speed.

Speed	Positioning speed V1
	Positioning speed V2
	Positioning address P2
	Time
	Positioning address P1

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.

Appendix - 68