Fuji Electric SPH Series - 3-3 Main Unit Parameters Configuration

3-4
Section 3 System Denition
3-3 Parameters for Main Unit
3-3-1 CPU running denition
The CPU running denition includes the following six setting items: “Watchdog timer setting”, “Running specication at power on”,
“Battery less run”, “Constant scanning setting”, “I/O status latch function”, and “LED display at built-in ash memory un-match”.
(1) Watch dog timer setting
The watchdog timer monitors default task execution time. If the execution time of the default task exceeds the value set here,
“application WDT error (%MX10.38.0)” is set ON and the main unit stops operation.
Watchdog timer can be set in the range from 2ms to 4095ms. The default setting is 4095ms.
(2) Running specication at power on
“RUN=Run/TERM=Run” (the mode that starts operation when the power is turned on) is selected for this parameter (xed).
(3) Battery less run
When “Battery less run” is ON, the main unit always initializes the data memory before starting operation. No memory backup
error (%MX10.9.15) is detected. The default setting is OFF.
(4) Constant scanning setting
Constant scanning is the function that sets the default task scan period and executes program at a given interval (0 to 255ms).
With this function, you can keep the interval to control external equipment at a constant value that does not depend on program
execution time and thus implement a control system that is small in the deviation of I/O response time.
Notes:
1) The constant scanning function does not reduce PLC scan time. Therefore, do not set a time value that is smaller than
ordinary scan time. If scan time exceeds the set value of constant scanning, ordinary scan is performed.
2) If the constant scanning and xed cycle task are used at the same time, the periodic task is not started within the period for
time adjustment in the constant scan time. Thus, the start timing of periodic task may vary.
(5) I/O status latch function
With this function, you can latch I/O status while the main unit stops running.
For ordinary operation, all outputs are set OFF and all inputs are refreshed when the main unit stops.
If “Effective” is selected for “I/O status latch function”, I/O status is latched when operation is stopped. If operation is resumed
without turning OFF the power supply to the main unit, operation is resumed from the previous condition.
* This parameter can be used as a simplied sampling trace function to monitor the status of all inputs and outputs in case of a
trouble by making a program that turns ON the fatal fault relay if the fault occurs in an external input switch, the troubles of
which are difcult to reproduce.
(6) LED display at built-in ash memory un-match
This parameter is used to determine whether or not to display on LED the mismatch in content between built-in ash memory
and RAM. Default is “Display” (display the mismatch on the LED). When “Not display” is selected, MEM LED does not blink even
in case of mismatch between the built-in ash memory and the RAM.
Default
task
Constant scan time
Operation
execution
Output processing
Input processing Time adjustment
Scan end
processing
Operation execution
Output processing
Input processing Time adjustment
Scan end
processing
Output processing
Input processing
Scan end
processing
Default task execution time
Default task execution period
Constant scan time