Technical data
  Fieldbus Communication • 235 
  MODBUS Functions 
WAGO-I/O-SYSTEM 750   
BACnet/IP Controller 
Register address 0x1005 (MODBUS Address 404102) 
Designation  Stop Watchdog, WD_AC_STOP_MASK 
Access  read / write 
Default 0x0000 
Description  This register is used to stop the watchdog timer by entering a value of 
0xAAAA followed by 0x5555. 
Register address 0x1006 (MODBUS Address 404103) 
Designation  While watchdog is running, WD_RUNNING 
Access read 
Default 0x0000 
Description  Current watchdog status. 
at 0x0000: Watchdog not active, 
at 0x0001: Watchdog active. 
at 0x0002: Watchdog exhausted. 
Register address 0x1007 (MODBUS Address 404104) 
Designation  Restart watchdog, WD_RESTART 
Access  read / write 
Default 0x0001 
Description  This register restarts the watchdog timer by writing a value of 0x1 into it. 
If the watchdog was stopped before the overrun, it is not restarted. 
Register address 0x1008 (MODBUS Address 404105) 
Designation  Simply stop watchdog WD_AC_STOP_SIMPLE 
Access  read / write 
Default 0x0000 
Description  This register stops the watchdog by writing the value 0x0AA55 or 0X55AA 
into it. The watchdog timeout fault is deactivated and it is possible to write 
in the watchdog register again. If there is an existing watchdog fault, it is 
reset 
Register address 0x1009 (MODBUS Address 404106) 
Designation  Close MODBUS socket after watchdog timeout 
Access  read / write 
Description  0: MODBUS socket is not closed 
1: MODBUS socket is closed 










