[ENG] 11.1. [DKSF 53/203.1 IU] What Is «Watchdog» and How to Configure It?

«Watchdog» is a specific operating mode of a relay channel within which indicated addresses are constantly requested by ping (ICMP Echo) with a certain frequency. If there is no response, a device, which is connected to a socket of a power supply channel, will reboot.

If specified IP addresses are not within a range of IP subnetwork of a device, there is a need to indicate a gateway address to the external network at the page «SETUP» of a device web interface.

To configure the module «Watchdog», there is a need to go to the page «WATCHDOG» of a device web interface:

where:

What is connected (memo, up to 30 characters) – a description of a relay which is entered into the field «Memo» at the page «RELAYS» of a device web interface.

Polling of Address A, B, C – is a set of check boxes which allow to specify addresses for polling individually. On default: checkboxes are not checked.

If no checkbox is checked or IP addresses for checked checkboxes are not indicated, polling will not be performed, therefore, the mode «Watchdog» will be disabled.

AddressA (B, C) – is a field to view or change addresses for polling. It is possible to indicate an IP address as well as a domain name. It is possible to configure up to three addresses. An empty field disables polling. On default: address is not specified.

Reset counter (cleared on firmware reboot) – is an informational field which shows how many times a channel has been rebooted as a result of actions of the module «Watchdog». A counter does not include manual reboots. A counter is reset when a power supply is cut off NetPing device.

Ping Polling Period, s (10-300) – is a field used to specify a period of time, within which repeated pings are sent to the indicated IP addresses after receiving a response from them. On default: 10 s

Ping Timeout, ms (600-9000) – is a field used to specify a timeout before repeating ping. A value must exceed a usual time needed to respond to ping for the network, with a certain reserve to avoid false triggering of the module «Watchdog». On default: 1000 ms

Max Ping Repeats after Timeout - is a field used to specify a maximum number of attempts to receive a response to «ping». If a number of attempts is over, an IP address is considered  to be «silent».  It is desirable to have a period of polling repeat longer than ping timeout multiplied by a maximum number of attempts. If this condition is not fulfilled, then a new cycle of polling will be postponed until an indicated amount of attempts is over.On default: 8

Reset Duration, s (1-900) – is a field for setting up time for which a device connected to a power supply outlet is cut off power to initiate reset and reboot.On default: 12 s.

Ping Polling Pause after Reset, s (1-3600) – is a field for setting up time for which polling is paused after turning on a power supply outlet. The pause is necessary for a device to load, initialize and restore the functioning of its network interfaces. Otherwise, it is possible for the mode «Watchdog» to trigger endlessly.On default: 15 с

Limit Number of Reset Retries (0 off, 1-255) – is a field for setting a number of consequent unsuccessful resets, after which the functioning of the load is not restored and there is still no response to ping. This situation may happen if the load stably fails, and its work is impossible to be restored by power switching on-switching off. When the limit is reached, resets are stopped but the periodic pinging is continued. Resets are unlocked when a response to ping is received. Stopping of resets and restoring of a regular operation order after a response to ping are registered in a log. The value «0» of this parameter disables the limit. On default: 0

Reset Polarity – is a field which allows to indicate what exactly will be done to reset a connected load: «Relay Off» or «Relay On» for an output power supply outlet. On default: Relay Off

Reset Condition Logic – determines a condition within which a reset of a device connected to a power supply channel will be done.

No reply from any of address A, B, C– a connected device will be reloaded if at least one of addresses have not responded.

No reply from all of addresses A, B, – a connected device will be reloaded only if all indicated addresses for polling have not responded.

No reply from address A and from one of В or С – a connected device will be reloaded if an address А has not responded together with either address В or С, or both B and C.

No reply from address А, but B or C replies – a connected device will be reloaded only if an address A has not responded, but address B or address C has responded. I.e. if all addresses do not respond, a reset of a connected device will not be done.

After setting all necessary parameters, click the button «Apply changes» for a device to execute a command. If any parameter will be set incorrectly, it will be highlighted with red colour:

There is a need to correct a value of a parameter and click the button «Apply changes» once more.

In order to unrdestand the process of the "Watchdog" module configuration better read the article «AUTOMATIC RELOADING OF A HANGING ROUTER THAT IS CONNECTED TO NETPING 2/PWR-220 V3/ETH POWER DISTRIBUTION UNIT».