WAGO-I/O-SYSTEM 750
CoDeSys 2.3 Runtime Environment 125
758-874/000-131 WAGO-I/O-IPC-C6
Manual
Version 1.0.0
11.9.3
Case 3: The CoDeSys task interval is greater than double
the I/O module cycle
The I/O data from the internal data bus are actualized once prior to the CoDeSys
task and once after the CoDeSys task.
Prior to processing the CoDeSys task, the I/O module cycle is implemented,
which provides the current input data for the CoDeSys task. After implementation
of the CoDeSys task, an additional I/O module cycle is started, which provides the
output data to the internal data bus.
This ensures that at the start of every CoDeSys task, current input data are
available from the internal data bus and the output data from each CoDeSys task
are quickly output to the internal data bus. This prevents processing of I/O module
cycles that would unnecessarily use a lot of computing time on the CPU.
KBZ
KBZ
KBZ
CT
CTI
CT
CTI
CTI
KBZ
t
Figure 56: I/O module synchronization 03
CTI: CoDeSys Task Interval
CT: CoDeSys Task that accesses the I/O module of the internal data bus
KBZ: I/O Module Cycle
Example:
CoDeSys-Task-Interval (CTI): 2000 µs
I/O Module Cycle (KBZ): 350 µs
Result:
Implementation of the I/O module cycle 350 µs before the CoDeSys Task
and once immediately after the CoDeSys Task.