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MELSEC-Q
7 SEQUENCE PROGRAM USED FOR POSITIONING CONTROL
Starting conditions
To start the control, the following conditions must be satisfied.
The necessary start conditions must be incorporated in the sequence program so
that the control is not started when the conditions are not satisfied.
Device
Signal name Signal state
Axis 1 Axis 2 Axis 3 Axis 4 Axis 5 Axis 6 Axis 7 Axis 8
PLC READY signal ON PLC CPU ready Y0
Module READY signal ON QD70 ready X0
Axis error occurrence signal OFF No error X1
Axis stop signal OFF Axis stop signal being OFF Y10 Y11 Y12 Y13 Y14 Y15 Y16 Y17
Start complete signal OFF Start complete signal being OFF X10 X11 X12 X13 X14 X15 X16 X17
Interface signal
BUSY signal OFF QD70 not operating X8 X9 XA XB XC XD XE XF
Operation when starting
(1) When the positioning start signal turns ON, the start complete signal and BUSY
signal turn ON, and the OPR control or positioning control 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 OPR control positioning control 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: 10)" will occur.
(4) The process taken when positioning control is completed will differ according to
case (a) and (b) below.
(a) When next positioning control is not to be carried out
• After the preset time of the dwell time has elapsed, positioning control is
completed.
• On completion of positioning control, the BUSY signal turns OFF and the
positioning complete signal turns ON. However, it does not turn ON if the
positioning complete signal output time is "0".
• When the positioning complete signal output time elapses, the positioning
complete signal turns OFF.
(b) When next positioning is to be carried out
• After the preset time of the dwell time has elapsed, next positioning control
is started.
Positioning start signal
[Y8 to YF]
OFF
ON
Start complete signal
[X10 to X17]
OFF
ON
BUSY signal
[X8 to XF]
OFF
ON
Positioning complete signal
[X18 to X1F]
OFF
ON
Positioning control
V
t
Dwell time
Dwell time Dwell time
Fig. 7.3 ON/OFF timing of each signal at start of positioning control
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