FB_EcGetExtSlaveState

The function block FB_EcGetExtSlaveState allows the EtherCAT status, the extended EtherCAT status and the link status of an individual EtherCAT slave to be read. If the call is successful, the output variable extState, whose type is ST_EcSlaveState, contains the requested status information. The function block FB_EcGetExtSlaveState is required when using the MX-System in order to detect empty MX slots (without an MX module inserted) in the PLC.

Inputs

VAR_INPUT
    sNetId     : T_AmsNetId; 
    nSlaveAddr : UINT; 
    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.
nSlaveAddr	UINT	Fixed address of the EtherCAT slave whose state is to be read.
bExecute	BOOL	The function block is enabled 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;
    extState : ST_EcExtendedSlaveState;
END_VAR

Name	Type	Description
bBusy	BOOL	This output is set when the function block is activated, and remains set until 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.
extState	ST_EcExtendedSlaveState	Structure that contains the extended EtherCAT status and the link status of the slave. (Type: ST_EcExtendedSlaveState)

Example for implementation in ST:

PROGRAM TEST_GetExtSlaveState
VAR
    fbGetExtSlaveState : FB_EcGetExtSlaveState;
    sNetId             : T_AmsNetId := '172.16.2.131.2.1';
    bExecute           : BOOL;
    extState           : ST_EcExtendedSlaveState;
    nSlaveAddr         : UINT := 1001;
    bError             : BOOL;
    nErrId             : UDINT;
END_VAR

fbGetExtSlaveState(sNetId:= sNetId, nSlaveAddr:= nSlaveAddr, bExecute:=bExecute);
extState := fbGetExtSlaveState.extState;
bError   := fbGetExtSlaveState.bError;
nErrId   := fbGetExtSlaveState.nErrId;

Requirements

Development environment	Target platform	PLC libraries to include
TwinCAT v3.1.4026.26	PC or CX (x86, x64, Arm^®)	Tc2_EtherCAT >= 3.8.1.0