Beckhoff KL6781, Documentation

Page: 21 / 32

Access from the user program
KL6781 21 Version: 2.0.0
Key
Bit Name Description
SW.15 ... SW.8 RegData: One byte of the data read from the register. The other byte is
transferred in the adjacent process data byte.
SW.7 RegAccess 1
bin
Acknowledgment for register access
SW.6 R 0
bin
Read access
SW.5 to SW.0 Reg. no. Number of the register that was read or written.
4.3 Process image
Note
No compact process image
The KL6781 cannot be operated with a compact process image (without control and status
word), since the control and status words are required for meaningful process data mode
operation of the terminal. The KL6781 is represented with its complex process image, even
if you set your Bus Coupler to a compact process image!
The KL6781 is represented in the process image with up to 24 bytes of input data and 24 bytes of output
data.
Format Input data Output data
Word
SW [
}
19] CW [
}
19]
Byte DataIn0 DataOut0
Byte DataIn1 DataOut1
... ... ...
Byte DataIn21 DataOut21
Key
SW: Status byte
CW: Control byte
DataIN 0 to DataIN 21: 22 bytes for the input data of the M-Bus
DataOUT 0 to DataOUT 21: 22 bytes for the output data of the M-Bus
• For the meaning of the control and status word please refer to the page Control and status word [
}
19] .
• Please refer to the Mapping [ } 22] page for the assignment of the bytes and words to the addresses
of the controller.