<< Click to Display Table of Contents >> Navigation:  »No topics above this level« PV access

mapp Services V5.16

•Show advanced parameter

"PV Access" defines which process variables in the project are permitted to be accessed.

If nothing is selected, then all variables that exist at runtime can be read- and write-accessed.

Different access groups can be defined using "Group". There are three possibilities here:

•All: "All" allows all variables in the project to be selected.

•All globals: If "All globals" is selected, a selection can be made for all global variables.

•Variable: A selection for a certain variable can be made with "Variable". The variable is defined under "PV name".

Whether read or write access is possible is defined for each group.

It is possible to select read access for all variables, for example ("All"). This makes all variables write-protected.

The variables that allow write access are then specified. This allows a command to be triggered, for example. In this example, write access is allowed for variables "Input" and "Output".

This ensures that write operations only take place on variables for which this is explicitly permitted.

If write access were permitted for all variables, then commands or values of a variable could be modified in such a way as to cause damage to a machine.

The following variables cannot be used:

Registration limitations:

•Arrays that do not start with index 0 cannot be registered.

•Multidimensional arrays cannot be registered.

•Arrays with more than 65535 elements cannot be registered.

•Derived data types

•TIME_OF_DAY

•BYTE

•WORD, DWORD, LWORD

•WSTRING

•LINT