FB_WritePersistentData 1:

The function block FB_WritePersistentData is an extended version of the WritePersistentData function block. The system behavior for writing the persistent data (data consistency/task cycle time overrun) can be influenced via the MODE parameter.


    NETID   : T_AmsNetId;
    PORT    : UINT;
    START   : BOOL;
    MODE    : E_PersistentMode;

NETID: This parameter can be used to specify the AmsNetID of the TwinCAT computer whose persistent data are to be saved (type: T_AmsNetID). If it is to be run on the local computer, an empty string can be entered.

PORT: The PORT parameter specifies the runtime system whose persistent data is to be stored.

START: the block is activated by a positive edge at this input.

TMOUT: States the length of the timeout that may not be exceeded by execution of the ADS command.

MODE : Mode in which the persistent data are to be written (type: E_PersistentMode).


    BUSY   : BOOL;
    ERR    : BOOL;

BUSY: When the function block is activated this output is set. It remains set until a feedback is received.

ERR: If an error should occur during the transfer of the command, then this output is set once the BUSY output was reset.

ERRID: Supplies the ADS error number when the ERR output is set.


See: Writing of persistent data: system behavior.

See: Example in the documentation for the WritePersistentData function block.


Development environment

Target platform

PLC libraries to be integrated (category group)

TwinCAT v3.1.0

PC or CX (x86, x64, ARM)

Tc2_Utilities (System)