Programming The Fm 351 - Siemens SIMATIC FM 351 Installation Manual

Programming
When you now write your program code, note that you only need to link the
Rules FCs which you actually need for your application.
Make sure that the separately written functions are mutually interlocked.
Generally, only one write job at a time may be executed on the FM 351.
Irrespective of the extent of the interlocks which you program, you should
ensure that the FC DIAG_INF is only called when really needed, that is with
a diagnostic interrupt. You set the condition for reading in the interrupt OB
(OB 82).
Note
Calling the FC DIAG_INF is not possible in the interrupt OB.
Decentralized The parallel calling of a number of functions in one cycle is not permitted.
Operation
You must program suitable interlocking mechanisms to prevent parallel call-
ing.
Centralized
Centralized operation enables the parallel calling of the separate functions in
Operation one cycle.
Chapter
Overview
6.1.1
6.1.2
6.1.3
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
Section
Principle of Communication between CPU and FM 351
Calling Functions
Interrupt Handling

Programming the FM 351

Contents
6
Page
6-4
6-6
6-8
6-3