Technical data

234 • Fieldbus Communication

MODBUS Functions

WAGO-I/O-SYSTEM 750

BACnet/IP Controller

Designation Watchdog function coding mask, function code 1...16, WDFCM_1_161...16

Access read / write

Default 0x0000

Description Using this mask, the specific function codes can be configured to reset the

watchdog function. The function code can be selected by writing a ‘1’ to the

appropriate bit(s) ( 2 (Function code-1) +2 (Function code-1... ).

Bit 1001.0 corresponds to function code1,

Bit 1001.1 corresponds to function code2...

A value of 0xFF enables MODBUS functions code 1 through 16 to reset the

watchdog. It is not possible to modify this value while the watchdog is running.

Designation Watchdog function coding mask, function code 17...32, WD_FCM_17_32

Access read / write

Default 0x0000

Description Same function as above, however, with the function codes 17 to 32. These

codes are currently not supported, for this reason the default value should not

be changed.. It is not possible to modify this value while the watchdog is

running.

Designation Watchdog-Trigger, WD_TRIGGER

Access read / write

Default 0x0000

Description This register is used to trigger the watchdog. The default value after power

up is 0. The writing of a non zero value will trigger the watchdog. The

watchdog is triggered each time the contents of this register are modified.

The watchdog cannot be triggered if the watchdog timer register is set to 0.

Designation Minimum current trigger time, WD_AC_TRG_TIME

Access read / write

Default 0xFFFF

Description This register stores the time value for the shortest remaining watchdog dura-

tion. The default value is 0xFFFF. When the watchdog timer is triggered,

this register is continuously compared to the remaining watchdog time, and

the lesser of the two values is stored in this register. If the value in this regis-

ter is 0, a watchdog fault has occurred.