FB_EcGetAllExtSlaveStates

The FB_EcGetAllExtSlaveStates function block can be used to read the EtherCAT status, the extended EtherCAT status, and the link status of all slaves connected to the master. If the call is successful, the buffer passed in the pStateBuf parameter contains the requested status information as an array of type ST_EcExtendedSlaveState. The function block FB_EcGetAllExtSlaveStates 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;
    pStateBuf : POINTER TO ARRAY[0..EC_MAX_SLAVES] OF ST_EcExtendedSlaveState;
    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.
pStateBuf	POINTER TO ARRAY[0..EC_MAX_SLAVES] OF ST_EcExtendedSlaveState	Address of an ARRAY of ST_EcExtendedSlaveStates into which the extended slave statuses are to be written.
cbBufLen	UDINT	Maximum available buffer size (in bytes) for the data 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;
    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 for implementation in ST:

PROGRAM TEST_GetAllExtSlaveStates
VAR
    fbGetAllExtSlaveStates : FB_EcGetAllExtSlaveStates;
    sNetId                 : T_AmsNetId := '172.16.2.131.2.1';
    bExecute               : BOOL;
    devStates              : ARRAY[0..255] OF ST_EcExtendedSlaveState;
    nSlaves                : UINT := 0;
    bError                 : BOOL;
    nErrId                 : UDINT;
END_VAR

fbGetAllExtSlaveStates(sNetId:= sNetId, pStateBuf := ADR(devStates), cbBufLen:=SIZEOF(devStates), bExecute:=bExecute);
nSlaves := fbGetAllExtSlaveStates.nSlaves;
bError  := fbGetAllExtSlaveStates.bError;
nErrId  := fbGetAllExtSlaveStates.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