PLC_ReadSymInfo 1:

The "PLC_ReadSymInfo" function block permits information regarding the symbols (variables) of a PLC run-time system.


    NETID  : T_AmsNetId;
    PORT   : T_AmsPort;
    START  : BOOL;

NETID: It is possible here to provide the AmsNetId of the TwinCAT computer whose symbol information is to be found (type: T_AmsNetID). If it is to be run on the local computer, an empty string can be entered.

PORT: The port number of a PLC run-time system (type: T_AmsPort).

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.


    BUSY     : BOOL;
    ERR      : BOOL;
    ERRID    : UDINT;

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.

SYMCOUNT: The number of symbols in the PLC run-time system.

SYMSIZE: Length of the data, in bytes, in which the symbol information is stored.


Development environment

Target platform

PLC libraries to be integrated (category group)

TwinCAT v3.1.0

PC or CX (x86, x64, ARM)

Tc2_Utilities (System)