ADLINK AMP-208C - Manual (Page 136)

Motion Control Theory 122
AMP-204C / AMP-208C
4.8 Motion Status Monitoring
During the motion control process it is necessary to monitor
motion status of control axis and convert to next process control at
appropriate time. Take example. Druing system initialization the
upper control program (the control program of user) execute
homing operation to each control axis at first. The controller starts
home movement once the command is received and the control
program must wait for the completion of homing operation. Usually
the polling method is used to determine the completion of homing
process. That is, read motion status signal of controller at regular
time span. Next stage control operation starts only after current
movement is completed.
In addition, there may be exceptional situations occurred during
motion operation. The upper control program must be able to
detect abnormality and deal with exceptions accordingly. Take
example. When emergency stop button is pressed during home
movement or the end limit signal is triggered during movement.
See figure below for basic flow chart of homing movement.
Figure 4-43: Motion status monitoring process
Motion control status and its behavior provided by this controller
shall be descirbed in Section 4.8.1.
Start home move
Polling home move
done?
Exception?
Next step control Error handling