Siemens SIMATIC FM 353 - Communication between the CPU and the FM 353; Programming Fundamentals

Programming the Technological Functions
6-4
FM 353 Stepper Drive Positioning Module
6ES7 353-1AH01-8BG0
6.1 Programming fundamentals
Overview
In this chapter you will find information on the following:
S Communication between the CPU and the FM 353, Section 6.1.1, p. 6-4
S Structure of a user program, Section 6.1.2, p. 6-5
S Distributed use of OB 86, Section 6.1.3, p. 6-6
S Embedding an OP, Section 6.1.4, p. 6-6
S Procedure for creating a user program, Section 6.1.5, p. 6-7
6.1.1 Communication between the CPU and the FM 353
Embedding the FM 353 in the user program
The diagram below shows you how the FM 353, the user DB and the technological
functions communicate.
User DB
CPU
POS_MSRM
POS_CTRL
POS_INIT
FM 353
OB 40
(process
interrupt)
4 bytes of OB
start information
OB 1
OB 82
(diagnostics)
POS_DIAG
OB 100
Restart (start-up)
4 bytes of OB start information
Read/write requests
Error message
(1 DB per channel)
1)
1) This block can only be called in OB 40 or in OB 1, but not in both simultaneously.
Diagnostic and
process inter-
rupt information
Control and
checkback sig-
nals
Data, error mes-
sage and error
specification
POS_MSRM
1)
Fig. 6-2 Overview diagram for linking the FM 353 into the user program