FB_EcGetSlaveCount

FB_EcGetSlaveCount 1:

The function block FB_EcGetSlaveCount can be used to determine the number of slaves that are connected to the master.

VAR_INPUT

VAR_INPUT
    sNetId      : T_AmsNetId;  
    bExecute    : BOOL;
    tTimeout    : TIME := DEFAULT_ADS_TIMEOUT; 
END_VAR

sNetId: This is a string that contains the AMS network identifier of the EtherCAT master device.

bExecute: The block is activated by a rising edge at this input.

tTimeout: Maximum time allowed for the execution of the function block.

VAR_OUTPUT

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

bBusy: This output is set when the function block is activated and remains set until an acknowledgement is received.

bError: This output is set up after the bBusy output has been reset if there has been an error in transmission of the command.

nErrId: Supplies the ADS error code associated with the most recently executed command if the bError output is set.

nSlaves: The number of slaves that are connected to the master.

 

Example of an implementation in ST:

PROGRAM TEST_GetSlaveCount
VAR
    fbGetSlaveCount : FB_EcGetSlaveCount;
    sNetId          : T_AmsNetId := '172.16.2.131.2.1';
    bExecute        : BOOL;
    nSlaves         : UINT;
    bError          : BOOL;
    nErrId          : UDINT;
END_VAR
fbGetSlaveCount(sNetId:= sNetId, bExecute:=bExecute);
nSlaves:=fbGetSlaveCount.nSlaves;
bError:=fbGetSlaveCount.bError;
nErrId:=fbGetSlaveCount.nErrId;

Requirements

Development environment

Target system type

PLC libraries to be linked

TwinCAT v2.10.0 or higher

PC or CX (x86)

TcEtherCAT.lib
( Standard.Lib; TcBase.Lib; TcSystem.Lib, TcUtilities.Lib are included automatically )

TwinCAT v2.10.0 Build >= 1301 or higher

CX (ARM)