Warnings/notes for accessing IOs

When declaring global variables based on a directly derived data type (see logi.CAD 3 user documentation, "Declaration of global variables in ST" and "Declaration of a directly derived data type in ST"), the pragma { SIZE := ...} must only be used, if:

1. the safety →PLC saves the data in little →endian format.

2. the data type is a data type of ANY_BIT (i.e., BOOL , BYTE , WORD , DWORD , LWORD) or of ANY_UNSIGNED (i.e., USINT , UINT , UDINT , ULINT).

Only specify exactly one task as designated IO task. Moreover, you have to deal with concurrency access issues. A task is designated as IO task by adding the pragma { IO } for the line specifying the task in the PLC object (see logi.CAD 3 user documentation, "Declaring more tasks within PLC-object").

When checking the build report, check the information on the IO task. The section containing the information on the program structure contains the information which task is the IO task. See "Building and loading the application onto the PLC" for details on the build report.

Perform an IO test, before the safety-relevant application is released. Observe all warnings/notes on such IOs and/or IO tests that are specified in the safety manual for the target platform.