Yaskawa MP920 User's Manual Design - Manual (Page 82)

3 Basic System Operation
3.2.2 Start Sequence
3-8
The MP920 start sequence and basic operations are as follows:
1. Startup Self-diagnosis
The following operations are provided for startup self-diagnosis:
• Memory (RAM) read/write diagnosis
• System program (ROM) diagnosis
• Main processor (CPU) function diagnosis
• Numeric co-processor (FCPU) function diagnosis
If an error occurs in the diagnostic result, the RDY indicator will flash the specified num-
ber of times.
2. Online Self-diagnosis
The following operations are provided for online self-diagnosis:
• System program (ROM) diagnosis
• Main processor (CPU) function diagnosis
• Numeric co-processor (FCPU) function diagnosis
If an error occurs in the diagnostic result, the RDY indicator will flash the specified num-
ber of times.
3. New Operation Start
Set the operation method for “New Operation” on the MPE720 System Definition Win-
dow. When the system is next started, the new operation will be used to start. Unlike a
continuous operation start, self-diagnostic processing is performed before DWG.A is
executed.
4. Continuous Operation Start
a) Set the operation method for “Continuous Operation” on the MPE720 System Defini-
tion Window. When the system is next started, the continuous operation will be used
to start. Unlike a new operation start, no self-diagnostic processing is performed.
Therefore, the startup time for drawing execution is shortened.
b) If the RUN switch is ON (RUN) or if it turns ON (RUN) from OFF (STOP), the CPU
starts the watchdog timer and then executes DWG.A.
c) Once the execution of DWG.A has been completed, the scan is started. The initial scan
is executed only after the time for the high-speed or low-speed scan has elapsed fol-
lowing the completion of DWG.A. System inputs and outputs are executed from the
first scan.
5. Operation Stop
The MP920 stops operating in the following cases:
a) When the power supply is interrupted (see * 1.)
b) When a power failure has occurred (see * 1.)
c) When a fatal error has occurred (see * 2.)
d) When a STOP operation has been performed from the MPE720 (see * 3.)
* 1. The MP920 can be restarted only by turning ON the power again.
* 2. Restart the system by turning the power OFF and ON. The cause of the
error can be ascertained by the indicator status.
* 3. Restart the system by performing a RUN operation from the MPE720.