Communications
configuring
System- and communication configuring D7-SYS - SIMADYN D
3-239
Edition 12.2003
3.21 Communications utility, message system
The message system allows the user to log certain events which he has
selected. A description of these events is collected in the message
sequence buffer and is then made available to the user via a data
interface.
The message system operates purely on the CPU. Precisely one central
block and at least one message evaluation block must be configured.
There are no configuring rules regarding the number of blocks.
The message system consists of 3 types of function blocks:
•
Central block @MSC
The central block sets-up the required data structures and administers
them. It is also responsible in evaluating communication- and system
error messages.
•
Message entry blocks MER ...
Message entry blocks generate messages when an input changes.
Message entry blocks can mutually interrupt each other. Thus, the
messages do not have to be entered in the message sequence buffer
in the sequence in which they occurred.
The message entry blocks differ by:
−
the number of messages which can be generated.
−
the capability of being able to process additional incoming process
conditions/statuses in the form of measured values.
•
Message evaluation blocks MSI ...
Message evaluation blocks output messages, generated by the
message entry blocks, via a data interface and make them accessible
to the user.
3.21.1
Entry logic of the message entry blocks
3.21.1.1
Message entry blocks for an activated message
For message entry blocks, which only generate an activated message,
the following conditions must be fulfilled for message entry:
•
input EN must be set.
•
a positive edge must be available at input I1.
•
connection Q1 or SM must be reset.
If the conditions are fulfilled, a message is generated and connection Q1
is set.
If the conditions are not fulfilled, then, if connection SM is reset,
connection Q1 is also reset.
General
Configuring
Function blocks for
the message
system
Entry logic