FB_EcGetAllSlaveAddr

FB_EcGetAllSlaveAddr 1:

The FB_EcGetAllSlaveAddr function block allows the addresses of all the slaves connected to the master to be read. When the call is successful, the buffer passed in the parameter pAddrBuf contains the addresses of all the slaves as an array of UINTs.

Inputs

VAR_INPUT
    sNetId   : T_AmsNetId;
    pAddrBuf : POINTER TO ARRAY[0..EC_MAX_SLAVES] OF UINT; 
    cbBufLen : UDINT 
    bExecute : BOOL; 
    tTimeout : TIME := DEFAULT_ADS_TIMEOUT; 
END_VAR

Name	Type	Description
sNetId	T_AmsNetId	String containing the AMS network ID of the EtherCAT master device. (Type: T_AmsNetId)
pAddrBuf	POINTER TO ARRAY [0..EC_MAX_SLAVES] OF UINT	Address of an array of UINTs into which the addresses of the individual slaves are to be written.
cbBufLen	UDINT	Maximum available buffer size (in bytes) for the data to be read.
bExecute	BOOL	The function block is activated by a positive edge at this input.
tTimeout	TIME	Maximum time allowed for the execution of the function block.

Outputs

VAR_OUTPUT
    bBusy   : BOOL;
    bError  : BOOL;
    nErrId  : UDINT;
    nSlaves : UINT; 
END_VAR

Name	Type	Description
bBusy	BOOL	This output is set when the function block is activated, and remains set until a feedback is received.
bError	BOOL	This output is set after the bBusy output has been reset when an error occurs in the transmission of the command.
nErrId	UDINT	Supplies the ADS error code associated with the most recently executed command if the bError output is set. Error 1798 (0x706) indicates a null pointer at the buffer address. Error 1797 (0x705) indicates inadequate buffer size.
nSlaves	UINT	The number of slaves connected to the master.

Example of an implementation in ST:

PROGRAM TEST_GetAllSlaveAddresses
VAR
    fbGetAllSlaveAddr : FB_EcGetAllSlaveAddr;
    sNetId            : T_AmsNetId := '172.16.2.131.2.1';
    bExecute          : BOOL;
    slaveAddresses    : ARRAY[0..255] OF UINT;
    nSlaves           : UINT := 0;
    bError            : BOOL;
    nErrId            : UDINT;
END_VAR

fbGetAllSlaveAddr(sNetId:= sNetId,pAddrBuf := ADR(slaveAddresses), cbBufLen:= SIZEOF(slaveAddresses), bExecute:=bExecute);
nSlaves := fbGetAllSlaveAddr.nSlaves;
bError := fbGetAllSlaveAddr.bError;
nErrId := fbGetAllSlaveAddr.nErrId;

Requirements

Development environment	Target platform	PLC libraries to include
TwinCAT v3.1.0	PC or CX (x86, x64, ARM)	Tc2_EtherCAT