BECKHOFF BK7300 - Manual (Page 36)

Appendix
32 BK7300
Appendix
MODBUS Interface
address Description
0x0000
0x00FF Process data interface
inputs
0x0800
0x08FF Process data interface
outputs
0x1000-
0x1006 Bus coupler identification
0x100A 2 byte PLC interface
0x100B Terminal diagnostics
0x100C Bus coupler status
0x1010 Process image length in bits Analogue outputs
0x1011 Process image length in bits Analogue 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
Read/Write
Watchdog Pre-defined time in [ms] 1000
0 watchdog deactivate; max: 0xFFFF ca. 65 sec
0x1121 Watchdog Reset Register
1 Telegram watchdog 0x1122 Type of Watchdogs
0 Write telegram watchdog (default)
Watchdog
The watchdog is active under the factory settings. After the first write telegram the watchdog timer is
initiated, and is triggered each time a write telegram is received from this device. Other devices have no
effect on the watchdog. A second approach is for the watchdog only to be re-triggered after each
telegram. To do this, write a one into register 0x1122 (default value "0").
The watchdog can be deactivated by writing a zero to offset 0x1120. The watchdog register can only be
written if the watchdog is not active. The data in this register is retained.