312 MODBUS – e!RUNTIME
WAGO-I/O-SYSTEM 750
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)
11.2.1.2 Register 0xFA01 – Watchdog Timeout
This register contains the value for the watchdog timeout. The step width is 1 ms
and the maximum value is 65535 (corresponds to 65.535 s). The default value is
0. In this case the watchdog cannot be started and will have the
WATCHDOG_UNCONFIGURED state.
The register can be read and written in the states
WATCHDOG_UNCONFIGURED and WATCHDOG_STOPPED. However, if the
watchdog is active or expired (WATCHDOG_RUNNING and
WATCHDOG_EXPIRED state), only read access to this register is possible. The
response to a write operation is an ILLEGAL_FUNCTION (0x01) exception.
11.2.1.3 Register 0xFA02 – Watchdog Status
This register provides the current state of the MODBUS watchdog.
The following states are possible:
Table 218: Watchdog Status
Value
Name
Explanation
0xFFFF
WATCHDOG_
UNCONFIGURED
The MODBUS watchdog is not configured, i.e.,
register 0xFA01 (Watchdog Timeout) contains
the value 0. Only the setting of a timeout > 0 s
can close this state.
0x0000
WATCHDOG_
STOPPED
The MODBUS watchdog is configured, the
register 0xFA01 (Watchdog Timeout) contains a
value >0. In the ADVANCED_WATCHDOG
operation mode, the watchdog can be activated
in this state with the WATCHDOG_START
command. In the SIMPLE_WATCHDOG
operation mode, this state cannot be accessed
since the watchdog is automatically started.
0x0001
WATCHDOG_
RUNNING
The MODBUS watchdog is active, i.e.
configured and started. The set timeout has not
yet expired.
0x0002
WATCHDOG_
EXPIRED
The timeout set in register 0xFA01 (Watchdog
Timeout) has expired. In the
ADVANCED_WATCHDOG operation mode, the
watchdog in this state must be reset to the
WATCHDOG_STOPPED state with the
WATCHDOG_RESET command. In the
SIMPLE_WATCHDOG operation mode, the
watchdog is automatically restarted with the
next trigger.