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MELSEC-Q
 
6   SEQUENCE PROGRAM USED FOR POSITIONING CONTROL 
 
 Servo ON conditions 
 
Setting of servo parameter 
 
PLC READY signal     Y0   ON 
 
All axis servo ON        Y1   ON 
 
 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 
PLC READY signal  ON  PLC CPU preparation completed  Y0 
QD75 READY signal  ON  QD75 preparation completed  X0 
All axis servo ON  ON  All axis servo is ON  Y1 
Synchronization flag  1 ON 
QD75 buffer memory 
Accessible 
X1 
Axis stop signal  OFF Axis stop signal is OFF.  Y4  Y5  Y6  Y7 
M code ON signal  OFF  M code ON signal is OFF.  X4  X5  X6  X7 
Error detection signal  OFF  No error is present.  X8  X9  XA  XB 
BUSY signal  OFF  BUSY signal is OFF.  XC  XD  XE  XF 
Interface 
signal 
Start complete signal  OFF  Start complete signal is OFF.  X10  X11  X12  X13 
Stop signal  OFF  Stop signal is OFF.  – 
Upper limit (FLS)  ON  Within limit range  – 
External 
signal 
Lower limit (RLS)  ON  Within limit range  – 
 
1: When the synchronous setting of the PLC CPU is made in the nonsynchronous mode, this must be 
provided as an interlock. 
When it is made in the synchronous mode, no interlock must be provided in the program because 
the flag is turned ON when calculation is run on the PLC CPU.