WAGO-I/O-SYSTEM 750
MODBUS – e!RUNTIME 311
750-8207 PFC200 CS 2ETH RS 3G
Manual
Draft version 1.2.1 from 2017-09-13, valid from FW Version 02.06.20(09)
11.2.1.1 Register 0xFA00 – Watchdog Command
This register receives commands for the MODBUS watchdog. It cannot be read,
i.e. it is not possible to read out the last command written.
The following commands are accepted depending on watchdog status:
Table 217: Watchdog Commands
Value
Name
Explanation
0x5555
WATCHDOG_
START
Starts the configured watchdog;
in the WATCHDOG_UNCONFIGURED state if
no timeout is configured, the response is an
ILLEGAL_DATA_VALUE (0x03) exception. The
same exception is returned even if the
watchdog has expired
(WATCHDOG_EXPIRED) in the ADVANCED_
WATCHDOG operation mode. The watchdog
must in this case be reset first with the
command WATCHDOG_RESET to the
WATCHDOG_STOPPED state. In all other
cases the watchdog is restarted and the
WATCHDOG_RUNNING state is set.
0x55AA
WATCHDOG_
STOP
Stops the running watchdog;
in the WATCHDOG_UNCONFIGURED state,
the response is an ILLEGAL_DATA_
VALUE (0x03) exception if no timeout time is
set. The same exception is returned even if the
watchdog has expired
(WATCHDOG_EXPIRED) in the ADVANCED_
WATCHDOG operation mode. The watchdog
must in this case be reset first with the
command WATCHDOG_RESET to the
WATCHDOG_STOPPED state. In the SIMPLE_
WATCHDOG operation mode the response is
an ILLEGAL_DATA_VALUE (0x03) exception.
The command is not generally permitted in this
operation mode. In all other cases, the
watchdog is stopped and the
WATCHDOG_STOPPED state is set. In the
WATCHDOG_STOPPED state a stop
command received several times in a row does
not have any impact on the behavior of the
watchdog and is therefore not acknowledged
with an error response.
0xAAAA WATCHDOG_
RESET
Resets the expired watchdog;
in the WATCHDOG_EXPIRED state the
ADVANCED_WATCHDOG operation mode
resets the watchdog. The watchdog is then in
the WATCHDOG_STOPPED state. In all other
cases the response is an ILLEGAL_
DATA_VALUE (0x03) exception.
