WAGO 750-341 Manual page 154

150 • Internal Variables
Description of the internal variables
Register address 0x1006 (MODBUS Address 404103)
Designation
Access
Default
Description
Register address 0x1007 (MODBUS Address 404104)
Designation
Access
Default
Description
Register address 0x1008 (MODBUS Address 404105)
Designation
Access
Default
Description
Register address 0x1009 (MODBUS Address 404106)
Designation
Access
Description
Register address 0x100A (MODBUS Address 404107)
Designation
Access
Default
Description
All register data is in word format.
Examples:
•
While watchdog is running, WD_RUNNING
read
0x0000
Current watchdog status.
at 0x0000: Watchdog not active,
at 0x0001: Watchdog active.
at 0x0002: Watchdog exhausted.
Restart watchdog, WD_RESTART
read / write
0x0001
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.
Simply stop watchdog WD_AC_STOP_SIMPLE
read / write
0x0000
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
Close MODBUS socket after watchdog timeout
read / write
0 : MODBUS socket is not closed
1: MODBUS socket is closed
Alternative watchdog
read / write
0x0000
This register provides an alternate way to activate the watchdog timer.
Proceedure: 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.
Set the watchdog for a timeout of 1 second. Function code 5 (Force Single
Coil) will be use to reset the watchdog time.
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
occurs.
) in the Coding Mask register (0x1001)
WAGO-I/O-SYSTEM 750
ETHERNET TCP/IP