Operation Manual EMGZ490A
30.08.2019
23
7.4
Functional Blocks, Example
Three functional blocks (FB1, FB2, FB3) were configured. These FBs were loaded to the
controller
Name
Description
Function
FB1 FMS_READ_FB
Reads a data package from the
specified slot and index
FB2
FMS_WRITE_FB
Writes a data package from the
specified slot and index
FB3 FMS_CYCLIC_FB
Reads cyclic data and writes it to a DB
The functional blocks are fetched cyclically, and if a read or write-instruction is required,
it is carried out. In PROFINET usually the organisational block OB1 is used, which is
fetched once every cycle. The sequence of function calls is shown in the following
diagram
:
The individual
FBs
read
or
write their data
to data
blocks
, which are
listed
below
Fig.
6:
Functional Blocks FB1 – FB2
E490012
