Allocated flags

4 kbyte of allocated flags are available. They can be used to assign different variable types to the same address, e.g. for converting strings to bytes. Data can also be placed here that can be read or written via ADS by the controller.

Allocated flags 1:

Allocated variables are not remanent data

For the Bus Terminal Controllers of the BX series and the BCxx50 the allocated variables are not saved as remanent data.

Reading/writing of allocated flags via ADS

The flags may also be read via the controller and ADS. In PROFIBUS, the DPV-1 services are used for this purpose, in CANopen SDO communication is used.
The AmsNetID can be obtained from the System Manager, or it can be displayed via the Bus Terminal Controller menu.
The PLC port number is 800.

Index group

Meaning

Index offset (value range)

0x4020

Flag (only BXxxx0)

0..4096

Example

BX program

VAR
    Flag_01 AT %MB0: WORD;
END_VAR

TwinCAT PC/CX master program

VAR
    fbADRSREAD: ADSREAD;
    Flag_M: WORD;
END_VAR
fbADRSREAD(
    NETID:='172.16.3.0.2.3' ,  (* AMSNetId BX *)
    PORT:=800 ,                (* 800 - PLC *)
    IDXGRP:=16#4020 ,          (* 0x4020hex falgs *)
    IDXOFFS:=0 ,               (* byte offset *)
    LEN:=2 ,                   (* Lenght byte *)
    DESTADDR:=ADR(Merker) ,
    READ:=TRUE ,
    TMOUT:=t#1s );
IF NOT fbADRSREAD.BUSY THEN
    fbADRSREAD(READ:=FALSE);
END_IF