Schneider Electric AP9635 manual Watchdog Features, Network interface watchdog mechanism

Watchdog Features

Overview

To detect internal problems and recover from unanticipated inputs, the Management Card uses internal, system-wide watchdog mechanisms. When it restarts to recover from an internal problem, a System: Warmstart event is recorded in the event log.

Network interface watchdog mechanism

The Management Card implements internal watchdog mechanisms to protect itself from becoming inaccessible over the network. For example, if the Management Card does not receive any network traffic for 9.5 minutes (either direct traffic, such as SNMP, or broadcast traffic, such as an Address Resolution Protocol [ARP] request), it assumes that there is a problem with its network interface and restarts.

Resetting the network timer

To ensure that the Management Card does not restart if the network is quiet for 9.5 minutes, the Management Card attempts to contact the default gateway every 4.5 minutes. If the gateway is present, it responds to the Management Card, and that response restarts the 9.5-minute timer. If your application does not require or have a gateway, specify the IP address of a computer that is running on the network most of the time and is on the same subnet. The network traffic of that computer will restart the 9.5- minute timer frequently enough to prevent the Management Card from restarting.

7 Network Management Card User’s Guide