Fig. 36 Function Block As An Example For Analysis Of Diagnostics Information Of The Box Module - Beckhoff EPP3504-0023 Short Manual

Commissioning
Fig. 36: Function block as an example for analysis of diagnostics information of the box module
Simplified linking via structure variable
This example program takes the opportunity to describe a TwinCAT function that simplifies the linking of
complex PDO structures.
This function block would have to be linked to all real time variables of the box module: inputs and outputs;
here e.g., for the ELM3602:
This time-consuming process can be simplified and accelerated by structuring in TwinCAT 3. Therefore, in
this chapter two alternative variants in TwinCAT 3.1 are presented, as with a few clicks a structure can be
defined in the PLC which corresponds to the process image of the box module.
The respective variant of the function block FB_REALTIME_DIAGNOSIS is included in the two example
programs. It contains variables with an application-specific data type. This is a structure created by
TwinCAT 3. Because the structure generated by TwinCAT directly maps the PDO structure of the box
module, it is not necessary that a suitable structure must be elaborately created, or individual variables must
be linked to individual data types. Only a link at a higher level (Status, Samples, Control, ...) is required.
This and all configurations are already included in the respective example program:
• Example program (variant A – using the "Plc" tab of the box module):
https://infosys.beckhoff.com/content/1033/epp3504/Resources/7161530379/.zip
• Example program (variant B – using of "Create SM/PDO Variables" by the advanced settings of the
box module):
https://infosys.beckhoff.com/content/1033/epp3504/Resources/7161533067/.zip
112 Version: 1.2 EPP3504-0023