WAGO 750-830 Manual page 236

236 • Fieldbus Communication
MODBUS Functions
Register address 0x100A (MODBUS Address 404107)
Designation Alternative watchdog
Access
Default
Description
All register data is in word format.
Examples:
Set the watchdog for a timeout of 1 second. Function code 5 (Force Single
Coil) will be use to reset the watchdog time.
Set the watchdog for a timeout of 10 minutes. Function code 3 (Read Multiple
Registers) will be use to reset the watchdog time.
read / write
0x0000
This register provides an alternate way to activate the watchdog timer.
Procedure: Write a time value in register 0x1000; then write a 0x0001 into
register 0x100A. With the first MODBUS request, the watchdog is started.
The watchdog timer is reset with each MODBUS/TCP instruction. If the
watch dog times out, all outputs are set to zero. The outputs will become
operational again, after communications are re-established.
1. Write 0x000A (1000ms /100 ms) in the Watchdog Timer register
(0x1000).
(5-1)
2. Write 0x0010 (2
3. Modify the value of the Watchdog-Trigger register (0x0003) to start the
watchdog.
4. At this point, the fieldbus master must continuously use function code 5
(Force Single Coil) within the specified time to reset the watchdog timer.
If time between requests exceeds 1 second, a watchdog timeout error oc-
curs.
To stop the watchdog after it is started, write the value 0x0AA55 or
0X55AA into it the Simply Stop Watchdog register (0x1008).
1. Write 0x1770 (10*60*1000 ms / 100 ms) in the register for time overrun
(0x1000).
(3-1)
2. Write 0x0004 (2
3. Modify the value of the Watchdog-Trigger register (0x0003) to start the
watchdog.
4. At this point, the fieldbus master must continuously use function code 3
(Force Single Coil) within the specified time to reset the watchdog timer.
If time between requests exceeds 10 minutes, a watchdog timeout error
occurs..
To stop the watchdog after it is started, write the value 0x0AA55 or
0X55AA into it the Simply Stop Watchdog register (0x1008).
) in the Coding Mask register (0x1001)
) in the Coding Mask register (0x1001)
WAGO-I/O-SYSTEM 750
BACnet/IP Controller