Output Description

DONE (done)

Data type: BOOL

Output DONE indicates the state of the job processing.

After completing or aborting the processing (due to an error), DONE is set to TRUE for one cycle. For that reason, the output always has to be considered together with output ERR. If ERR is TRUE, an error occurred. In this case, the error number can be read at output ERNO.

ERR (error)

Data type: BOOL

Output ERR indicates whether an error occurred during the Function Block processing.

This output always has to be considered together with output DONE. If DONE is TRUE and ERR is TRUE, an error occurred. In this case, the error number can be read at output ERNO.

ERNO (error number)

Data type: WORD

Output ERNO provides an error identifier, if an invalid value was applied to an input or if an error occurred during the request processing. ERNO always has to be considered together with the outputs DONE and ERR. The value output at ERNO is only valid, if DONE is TRUE and ERR is TRUE.

The error messages Error Messages of the Function Block Libraries encoding at output ERNO are explained at the beginning of the library description.

DATA_LEN (data length)

Data type: BYTE

Output DATA_LEN displays the length (in bytes) of the output data read by the slave.

DATA_LEN is only valid, if DONE is TRUE and ERR is 0. If DATA_LEN contains a value X which is not 0, the Function Block has stored X bytes of output data in the variable specified at DATA.

Example

If DATA is a byte array with start index 1, the valid output data of the slave are contained in the entries DATA[1] to DATA[X].