FB_MDP_IdentityObj_Read 1:

Der Funktionsbaustein ermöglicht die Abfrage der Tabelle IdentityObject der General Area der IPC-Diagnose.


    bExecute  : BOOL; (* Function block execution is triggered by a rising edge at this input.*)
    tTimeout  : TIME := DEFAULT_ADS_TIMEOUT; (* States the time before the function is cancelled. *)
    sAmsNetId : T_AmsNetId; (* keep empty '' for the local device *)

bExecute: The function block is called by a rising edge on the input bExecute, if the block is not already active.

tTimeout: Specifies a maximum length of time for the execution of the function block.

sAmsNetId: To execute the query on the local device, it is not necessary to specify this input variable. Alternatively, an empty string can be specified. To direct the query to another computer, its AMS Net Id (of type T_AmsNetId) can be specified here.


    bBusy   : BOOL;
    bError  : BOOL;
    nErrID  : UDINT;
    iErrPos : USINT;
    stMDP_ModuleContent : ST_MDP_IdentityObject;

bBusy: This output is TRUE as long as the function block is active.

bError: Becomes TRUE as soon as an error situation occurs.

nErrID: Returns an error code if the bError output is set.

iErrPos: If an error occurred and this refers to an individual element, then this output indicates the position (subindex of the element) at which an error first occurred.

stMDP_ModuleContent: The information from the table is displayed at this output in the form of the structure ST_MDP_IdentityObject.


Serial number is no longer supported

Outdated parameter leads to error situation

In the Identity Object the serial number of the IPC is read from the MDP General Area. This parameter is obsolete. The parameter is no longer supported for newer Beckhoff IPC devices. This causes the function block to return an error and name the error position (iErrPos = 4), which corresponds to the iSerialNumber parameter.
Alternatively, the serial number can be read from the MDP Device Area. See corresponding example.
It is recommended to use the PLC library Tc3_IPCDiag, which is the successor to the PLC library Tc2_MDP.



Development environment

Target platform

PLC libraries to include

TwinCAT v3.1.0

PC or CX (x86, x64, ARM)