FB_EcSoeRead

The function block FB_EcSoeRead can be used to read drive parameters by means of the “Sercos over EtherCAT (SoE)” protocol. To this end the slave must have a mailbox and support the SoE protocol. The drive parameter to be read is specified with the parameters nIdn (identification number), nElement and nDriveNo.

Inputs

VAR_INPUT
    sNetId     : T_AmsNetId; 
    nSlaveAddr : UINT; 
    nIdn       : WORD;
    nElement   : BYTE;
    nDriveNo   : BYTE;
    bCommand   : BOOL
    pDstBuf    : PVOID; 
    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)
nSlaveAddr	UINT	Fixed address of the EtherCAT slave to which the SoE read command is to be sent.
nIdn	WORD	Identification number of the parameter to be read
nElement	BYTE	Element number of the parameter to be read (See nElement)
nDriveNo	BYTE	Drive number
bCommand	BOOL	This parameter should be set if internal command execution is to be used.
pDstBuf	PVOID	Address (pointer) to the receive buffer
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.

nElement

Element number of the parameter to be read. The following values are permitted:

Value	Description
0x01	Data status
0x02	Name (read only)
0x04	Attribute
0x08	Unit
0x10	Minimum
0x20	Maximum
0x40	Value
0x80	Default

Outputs

VAR_OUTPUT
    bBusy  : BOOL;
    bError : BOOL;
    nErrId : UDINT;
    cbRead : UDINT;
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.
cbRead	UDINT	Number of successfully read data bytes

Example of an implementation in ST:

PROGRAM TEST_SoERead
VAR
    fbSoERead   : FB_EcSoERead;
    sNetId      : T_AmsNetId:= '172.16.2.131.2.1';
    bExecute    : BOOL;
    nSlaveAddr  : UINT := 1006;
    nIdn        : WORD := 15;
    nElement    : BYTE := 0;
    nDriveNo    : BYTE := 0;
    bCommand    : BOOL := FALSE;
    val         : UINT;
    bError      : BOOL;
    nErrId      : UDINT;
END_VAR

fbSoERead(sNetId:= sNetId,nSlaveAddr :=nSlaveAddr, nIdn := nIdn, nElement:=nElement, nDriveNo := nDriveNo, bCommand:=bCommand, pDstBuf:= ADR(val), cbBufLen:=SIZEOF(val),bExecute:=bExecute);
bError := fbSoERead.bError;
nErrId := fbSoERead.nErrId;

Prerequisites

Development environment	Target platform	PLC libraries to include
TwinCAT v3.1.0	PC or CX (x86, x64, Arm^®)	Tc2_EtherCAT