6 SEQUENCE PROGRAM USED FOR POSITIONING CONTROL

[1] Starting by inputting positioning start signal

Operation when starting

MELSEC-Q

(1)When the positioning start signal turns ON, the start complete signal and BUSY signal turn ON, and the positioning operation starts.

It can be seen that the axis is operating when the BUSY signal is ON.

(2)When the positioning start signal turns OFF, the start complete signal also turns OFF.

If the positioning start signal is ON even after positioning is completed, the start complete signal will remain ON.

(3)If the positioning start signal turns ON again while the BUSY signal is ON, the warning "operating start (warning code: 100)" will occur.

(4)The process taken when positioning is completed will differ according to case

(a)and (b) below.

(a)When next positioning is not to be carried out

If a dwell time is set, the system will wait for the set time to pass, and then positioning will be completed.

When positioning is completed, the BUSY signal will turn OFF and the positioning complete signal will turn ON. However, when using speed control or when the positioning complete signal ON time is "0", the signal will not turn ON.

When the positioning complete signal ON time is passed, the positioning complete signal will turn OFF.

(b)When next positioning is to be carried out

If a dwell time is set, the system will wait for the set time to pass.

When the set dwell time is passed, the next positioning will start.

 

V

 

Dwell time

Positioning

t

 

ON

Positioning start signal

OFF

[Y10, Y11, Y12, Y13]

 

 

ON

Start complete signal

OFF

[X10, X11, X12, X13]

 

 

ON

BUSY signal

OFF

[XC, XD, XE, XF]

 

 

ON

Positioning complete

OFF

signal

 

[X14, X15, X16, X17]

 

Fig. 6.3 ON/OFF timing of each signal at start of positioning

POINTS

The BUSY signal [XC, XD, XE, XF] turns ON even when position control of movement amount 0 is executed. However, since the ON time is short, the ON status may not be detected in the sequence program.

(The ON status of the start complete signal [X10, X11, X12, X13], positioning complete signal [X14, X15, X16, X17] and M code ON signal [X4, X5, X6, X7] can be detected in the sequence program.)

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Mitsubishi Electronics QD75D, QD75P user manual Starting by inputting positioning start signal, Operation when starting