IDEC High Performance Series - Manual (Page 1241)

WindO/I-NV2 User’s Manual 29-7
2 Digital I/O Units
29
Expansion Modules
■ Output delay
The min-to-max delay time for HG Digital Output (LEY) to fire from the digital I/O unit is 1 ms to 1 ms + the
Execution Period.
■ Cyclic Script
A Cyclic Script refers to three processes: input refresh, I/O control (the specified script), and output refresh.
Refer to “3 Cyclic Script” on page 29-9 for programming information.
■ Sleep
Sleep refers to the time used by the Cyclic Script subtracted from the Execution Period. This is when the processor
executes display processing.
■ Execution Period
The Execution Period refers to one scan of the Cyclic Script (input refresh + I/O control + output refresh) and display
processing time (sleep).
The Cyclic Script is executed once every specified execution interval.
■ Display processing
Parts laid out on the screen are processed from top to bottom only when the Cyclic Script is in sleep mode.
Display processing pauses when execution of the next Cyclic Script begins, and resumes when the script goes to sleep
again.
When processing reaches the bottom of the screen, processing returns to the top of the screen.
When an output is sent to the digital I/O unit immediately after the
output refresh ends, the output delay will be the longest because the
processor waits for the output refresh in the next scan before
reflecting the output to the HG Digital Output (LEY).
LEY
Y
Input refresh
Output refresh
I/O control
Sleep
(Display
processing
executed)
Input refresh
Output refresh
I/O control
Output delay
(maximum)
HG Digital
Output
External
output
• Only internal devices can be used in the Cyclic Script.
• The actual execution time of the Cyclic Script is stored in HG special register LSD 38 (current value x
ms), LSD 39 (max value x ms), and LSD 40 (min value x ms).
• Cannot use the LINE function, RECTANGLE function, CIRCLE function in the Cyclic Script.
• If execution of the Cyclic Script takes more than half of the time specified for the Execution Period, the
processor automatically extends the Execution Period so that the Cyclic Script completes within 1/2 of the
Execution Period. In this instance, error number 7 will be stored in HG special register LSD53.
• If the execution time of the Cyclic Script exceeds 3,000 milliseconds, it pauses to allow the output refresh
to be executed. Thereafter, the script goes to sleep and the Cyclic Script executes on the next scan. In
this instance, error number 6 will be stored in HG special register LSD53.
There is a delay in the I/O control. Take this delay time into consideration when specifying the Execution
Period.
For instance, if it is necessary to capture external inputs within 100 ms, set the Execution Period to 80 ms.