BECKHOFF BK7300 - Manual (Page 37)

Appendix
BK7300 33
Watchdog register
If the watchdog timer on your slave has elapsed it can be reset by writing twice to register 0x1121. The
following must be written to the register: 0xBECF 0xAFFE. This can be done either with function 6 or with
function 16.
Bus
coupler status 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0x100C FB CN
F KB
FB:
Fieldbus error, watchdog time elapsed
KB: terminal bus error
CNF: BK configuration window
2 byte PLC interface/
2 byte diagnostic interface
Registers in the complex terminals and bus coupler registers can both be
read or written using the 2 byte PLC interface. The complex terminal
registers are described in the associated terminal documentation. The bus
coupler registers can be used, for example, to read terminal bus
diagnostics data, the terminal composition or the cycle times, and the
programmed configuration can be written. It is also possible for a manual
terminal bus reset to be carried out. The 2-byte PLC interface requires two
bytes each of output and input data. They are handled using a special
protocol. A description of the 2 byte PLC interface, the registers available
in the bus couplers and of function blocks for various PLC that implement
the 2 byte PLC interface can be supplied on request.
The terminals' error messages can be sent over the 2-byte diagnostic
interface. Terminal bus diagnostics must however be activated for this
purpose. The 2-byte diagnostic interface occupies two bytes each of output
and input data. They are handled using a special protocol. A description of
the 2 byte-diagnostic interface can be supplied on request.