eipWriteAttr

 Function Block - Sends an explicit message (UCMM) to an EtherNet/IP adapter to write a single CIP attribute.

Inputs

Input	Data Type	Range	Unit	Default	Description
Attr	UINT				Identifier of the CIP attribute.
Class	UINT				Class identifier of the CIP object.
Data	array of UINT				Buffer containing the data to write.
Inst	UINT				Instance identifier of the CIP object.
SrvIP	STRING				IP address of the server (adapter) (e.g., configured in the EtherNet/IP Scanner configuration).
Size	UINT				Number of bytes to write. Cannot exceed 450 bytes.
Snd	BOOL	FALSE, TRUE	N/A	No default	A rising edge on this input starts the exchange. The DONE output signals the end of exchange.

Outputs

Output	Data Type	Range	Unit	Description
Done	BOOL	FALSE, TRUE	N/A	This output is TRUE during one cycle when the exchange is finished, whether the exchange succeeded or failed. Warning: This output can be TRUE just after the call to block when starting a new exchange in case of invalid parameters.
EmErr	UINT			In case of a UCMM error, this is the CIP general status error code.
EmErrExt	UINT			In case of a UCMM error, this is the CIP extended status error code.
Err	UINT			Main error report. Can be one of these values: 0 = No error. 1 = Invalid input arguments. 2 = System is busy (see remarks). 3 = Timeout waiting for the answer (the timeout value is 3 seconds). 4 = UCMM error was returned by the server others = internal errors (reserved for technical support).
RcvSize	UINT			Actual size of the CIP attribute answered by the server. If this size is greater than the size of the DATA input array, it indicates the value was truncated.

Remarks

• The CIP instance number can be 16-bits [1...65535].
• The servers (adapters) accessed by this block must be configured in the EtherNet/IP Scanner fieldbus configuration.
• Only one explicit message (read or write) can be sent at one time to the same server.
  • If another message is pending you receive the error report 3 (busy) after calling the block to start a new exchange.
• Consider SerializeIn and SerializeOut functions for extracting data from the read buffer.

FBD Language Example

Not available.

FFLD Language Example

Not available.

IL Language Example

Not available.

ST Language Example

// used variables
// Inst_eipWriteAttr : eipWriteAttr ;
// bWrite : BOOL ; (* request for WRITE *)
// DataWrite : ARRAY [0 .. 15] OF USINT; (* written data *)
// uiSizeWrite : UINT := UINT#16 ; (* number of bytes to read *)
// Server identification and CIP things
#define SRVIP '192.168.33.21'
#define CLASSID UINT#100
#define INSTID_WRITE UINT#2
#define ATTRID UINT#3
/////////////////////////////////////////////////////////////////////////////////////////
// requested WRITE command
if bWrite then
    Inst_eipWriteAttr (bWrite, SRVIP, CLASSID, INSTID_WRITE, ATTRID,
                       uiSizeWrite, DataWrite);
end_if;
// WRITE answer here ?
if Inst_eipWriteAttr.Done then
// check answer
    if Inst_eipWriteAttr.Err = 0 then
        printf ('WRITE ok');
    else
        printf ('WRITE Error %lu - (UCMM Error %lu, %lu)',
            any_to_dint (Inst_eipWriteAttr.Err),
            any_to_dint (Inst_eipWriteAttr.EmErr),
            any_to_dint (Inst_eipWriteAttr.EmErrExt));
    end_if;
// reset WRITE command and block input
    Inst_eipWriteAttr (false, SRVIP, CLASSID, INSTID_WRITE, ATTRID,
                       uiSizeWrite, DataWrite);
    bWrite := false;
end_if;

See Also

• eipAdapter
• eipReadAttr