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.

Inputs

VAR_INPUT
    sNetId   : T_AmsNetId; 
    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)
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.
nSlaves	UINT	The number of slaves 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 platform	PLC libraries to include
TwinCAT v3.1.0	PC or CX (x86, x64, ARM)	Tc2_EtherCAT