Chapter 5 Programming Concepts
XBC E-Type Main Unit
5-2
Ver. 1
1. Scan program
a. Function
i. This program performs the operation repeatedly from 0 step to last step in order
to process the signal that is repeatedly regularly every scan.
ii. When the execution condition of the interrupt by task interrupt or interrupt
module when execution the program is met, the current program stops and
performs the applicable interrupt program.
2. Interrupt program
a. Function
i. This program stops the operation of scan program and then processes the
related function in prior to process the internal/external signal occurred
periodically/non-periodically.
b. Type
i. Task program is divided as below.
I.
Cycle time task program: available to use up to 8.
II. Internal device task program: available to use up to 8.
III. I/O (External contact task program): “E” type available to use up to 4.
(P000~P003)
ii. Cycle time task program
I.
Performs the program according to the fixed time interval.
iii. Internal device task program
I.
Executes the corresponding program when the start condition of
internal device occurs.
II. The start condition detection of device shall be executed after
processing of scan program.
iv. I/O (External contact task program)
I.
Executes the program according to the input external signal (“E” type:
P000~P003).
Remark
(1) Write the interrupt program as short as possible. When same interrupt occurs repeatedly
before completion of interrupt, program is not executed, and O/S watch dog error may occur.
(2) If interrupt with lower priority occurs several times during execution of interrupt with higher
priority, lower priority interrupt occurs only one time.
Summary of Contents for XBC-DN10E
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