Systemsoftware
System- and communication configuring D7-SYS - SIMADYN D
2-17
Edition 03.2001
The assignment of the function blocks to the cyclic tasks and the interrupt
tasks can be changed using the
Edit
>
Sequence
menu item.
When configuring has been completed, the generated software can be
checked with the
Chart
>
Check consistency
menu item, and then
compiled into the machine code with
Chart
>
Compile
.
The
Target system
>
Load
menu item then allows the memory module
to be programmed.
2.1.6 Description and use of the signal transfer mechanisms
Signal transfer is data exchange between various blocks.
e. g. integrator
e. g. multiplier
1ms ; 1. CPU
4,2 ms ; 2. CPU
Signal transfer
Fig. 2-3
Data transfer between two tasks
2.1.6.1 Data consistency
For interconnections between different cyclic tasks, SIMATIC
TDC/SIMADYN D ensures the consistency of all data which is
transferred. This means, that all data transferred from a task come from
the same computation cycle of this task. All values calculated during a
sampling cycle are "exported" at the end of the task. When starting a
task, the required values are "imported", whereby it is ensured that there
is no overlap (from a time perspective) between reading and writing the
values (buffer system). As deadtimes are unavoidable with this concept,
a signal should not be routed via several tasks and CPUs - if this can be
avoided.
A differentiation is made between the following signal transfer types :
•
Data transfer within the same task of a CPU
•
Data transfer between various tasks of a CPU
•
Data transfer between cyclic tasks of several CPUs
•
Data transfer between alarm tasks of several CPUs
