eipWriteAttr

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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
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.
SrvIP	STRING	No range	N/A	No default	IP address of the server (adapter) (e.g., configured in the EtherNet/IP Scanner configuration).
Class	UINT	No range	N/A	No default	Class identifier of the CIP object.
Inst	UINT	1 to 65535	N/A	No default	Instance identifier of the CIP object.
Attr	UINT	No range	N/A	No default	Identifier of the CIP attribute.
Size	UINT	1 to 450	N/A	No default	Number of bytes to write. Cannot exceed 450 bytes.
Data	USINT[ ]	Dimension: The number of bytes to write. Data: No range	N/A	No default	Buffer containing the data to write.

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.
Err	UINT	No range	N/A	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).
EmErr	UINT	No range	N/A	In case of a UCMM error, this is the CIP general status error code.
EmErrExt	UINT	No range	N/A	In case of a UCMM error, this is the CIP extended status error code.

Remarks

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;