YASKAWA SVC User Manual page 382

Two sets of buffers are needed to save the power OFF encoder position and the power OFF
pulse position because the program may end without setting all four words of the position infor-
mation if the power supply is turned OFF during the high-speed scan.
Important
The following flowchart shows the procedure for storing this information to these buffers.
Start of high-speed scan drawing
YES
Is this the first scan after the
high-speed scan started?
Is operation not ready and
is there a current alarm?
Is the origin setting
completed status ON?
Has the set ori g i n operati o n been compl e ted and i s
the Posi t i o n Informati o n Save Request Fl a g set to 1?
Is the Toggle Buffer Enabled Flag set to 1?
Is the Toggle Buffer Selection Flag set to 1?
Copy the value of the monitor
parameters to buffer 0.
Set the Toggle Buffer Selection Flag to 0.
End of high-speed scan drawing
The example of ladder programming on the next page is for the above flowchart. Axis 1 of cir-
cuit number 1 is used here. Change the motion parameter register address if the circuit and/or
axis numbers are different.
5.2.6 Position Management Method for Each Machine Operation Type
NO
YES
NO
Position Information Save Request Flag = 0
YES
NO
Position Information Save Request Flag = 1
NO
YES
NO
YES
Copy the value of the monitor
parameters to buffer 1.
Set the Toggle Buffer Selection Flag to 1.
5.2 Absolute Encoders
5-41
5