FB_EcGetAllSlaveStates

FB_EcGetAllSlaveStates 1:

The FB_EcGetAllSlaveStates function block allows the EtherCAT status and the Link status of all the slaves connected to the master to be read. When the call is successful, the buffer passed in the parameter pStateBuf contains the requested status information as an array of ST_EcSlaveState.

FB_EcGetAllSlaveStates 2: Inputs

VAR_INPUT
    sNetId    : T_AmsNetId;
    pStateBuf : POINTER TO ARRAY[0..EC_MAX_SLAVES] OF ST_EcSlaveState;
    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)

pStateBuf

POINTER TO ARRAY[0..EC_MAX_SLAVES] OF ST_EcSlaveState

The address of an array of ST_EcSlaveStates into which the slave states 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.

FB_EcGetAllSlaveStates 3: 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_GetAllSlaveStates
VAR
    fbGetAllSlaveStates : FB_EcGetAllSlaveStates;
    sNetId              : T_AmsNetId := '172.16.2.131.2.1';
    bExecute            : BOOL;
    devStates           : ARRAY[0..255] OF ST_EcSlaveState;
    nSlaves             : UINT := 0;
    bError              : BOOL;
    nErrId              : UDINT;
END_VAR

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

Requirements

Development environment

Target platform

PLC libraries to include

TwinCAT v3.1.0

PC or CX (x86, x64, ARM)

Tc2_EtherCAT