Function library lenzeiosystem.lib, Application examples – Lenze DDS Function library IOSystem User Manual
Page 16

3.2
Compact decentralised I/O system
Function library LenzeIOSystem.lib
Application examples
3−6
L
LenzeIOSystem.lib EN 1.7
Note!
·
Enter a minimum time of ten seconds for step Init via the menu command Extras
ÞStep
attributes.... Correct entry: T#10s
Make sure that step Parameter_data is not executed before the initialisation phase of the I/O system
is complete. This is achieved with a minimum time of ten seconds.
As this POU must be processed cyclically, the program is invoked in the PLC_PRG (main program).
The sequential function chart ensures a cyclic task.
The parameterisation process is started via the initial action in step ParCompact.
Once the parameterisation is complete, the final action in step ParCompact sets input bExecute to
FALSE and variable bStart to TRUE.
Variable bStart ensures that step ParCompact is executed
·
on switching on
·
on reset and subsequent starting.
When the parameterisation is complete, the PLC_PRG (main program) stops in step Init. It does not
impose an extra burden on the target system during subsequent program operation.
Programming the process data exchange between PLC and I/O system
The CFC editor is used to generate a program named Process.
·
Declare an instance of function block L_IOCompactModule in Process.
·
Generate two inputs in the CFC editor, assign names g_bParDone15 and g_ParData15 and
attach these to the corresponding inputs of function block L_IOCompactModule as shown in
the figure.
Several conversion blocks are available to evaluate input data and to transfer output data.
Function block L_IOCompactModule transmits output data to the I/O system and receives input
data from there.