Appendix
BC7300
41
Appendix
MODBUS Interface
Address
Description
0x0000
0x00FF
Process data interface
Inputs (%QBx)
0x0800
0x08FF
Process data interface
Outputs (%IBx)
0x1000-
0x1006
Bus Coupler identification
0x100A
2 byte PLC interface
0x100B
Terminal diagnostics
0x100C
Bus Coupler status
0x1010
Process image length in bits
Analog outputs
0x1011
Process image length in bits
Analog inputs
0x1012
Process image length in bits
Digital outputs
0x1013
Process image length in bits
Digital inputs
0x1020
Only Read
Watchdog
Current time in [ms]
1000
0x110A
2 byte PLC interface
0x110B
Terminal diagnostics
0x1120
Watchdog
Pre-defined time in [ms]
1000
0x400
0x40FF
Read/Write
Flag range
3
%MB0 - %MB511
Bus Coupler status 15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
0x100C
FB
CNF 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 PLCs 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.
3
From Firmware B4