Lenze PLC Designer PLC Designer (R2-x) - Manual (Page 171)

L-force | PLC Designer
The Individual Components

DMS 3.2 EN 02/2011 TD29 169
6.3.40 Unused Variables
This function in the 'Project' 'Check' menu searches for variables that have been
declared but not used in the program. They are outputted by POU name and line, e.g.:
PLC_PRG (4) – var1. Variables in libraries are not examined.
Results are displayed in the message window.
6.3.41 Overlapping memory areas
This function in the 'Project' 'Check' menu tests whether in allocation of variables via
the "AT" declaration overlaps have arisen at specific memory areas. For example, an
overlap occurs when allocating the variables "var1 AT %QB21: INT" and "var2 AT
%QD5: DWORD" because they both use byte 21. The output then appears as follows:
%QB21 is referenced by the following variables:
PLC_PRG (3): var1 AT %QB21
PLC_PRG (7): var2 AT %QD5
Results are displayed in the message window.
6.3.42 Multiple Write Access on Output
This function of the 'Project' 'Check' menu searches for memory areas to which a
single project gains write access at more than one place. The output then appears as
follows:
%QB24 is written to at the following locations:
PLC_PRG (3): %QB24
PLC_PRG.POU1 (8): %QB24
Results are displayed in the message window.
6.3.43 Concurrent Access
This function in the 'Project' 'Check' menu searches for memory areas of IEC addresses
which are referenced in more than one task. No distinction is made here between read
and write access. The output is for example:
%MB28 is referenced in the following tasks :
Task1 – PLC_PRG (6): %MB28 [read-only access]
Task2 – POU1.ACTION (1) %MB28 [write access]
Results are displayed in the message window.