GÜDE Expert Power Control 8291, Manual

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Expert Power Control 8291 © 2020 GUDE Systems GmbH
Configuration
· Red text: The watchdog is active and receives no ping replies anymore from the con-
figured IP address.
After the watchdog has been enabled, the display remains orange until the watchdog re-
ceives a ping response for the first time. Only then the watchdog is activated. Even after
triggering a watchdog and a subsequent power port reset, the display will remain orange
until the device is rebooted and responds again to ping requests. This will prevent a pre-
mature watchdog reset of the port, e.g. when a server needs a long time for a file check.
You can monitor devices on your own network, as well as devices on an external net-
work, e.g. the operating status of a router.
Enable watchdog: Enables the watchdog function for this Power Port.
Watchdog type: Here you can choose between the monitoring by ICMP pings or TCP
pings.
· ICMP Pings: The classic ping (ICMP echo request). It can be used to check the ac-
cessibility of network devices (for example, a server).
· TCP Pings: With TCP pings, you can check if a TCP port on the target device would
accept a TCP connect. Therefore a non-blocked TCP port should be selected. A good
choice would be port 80 for http or port 25 for SMTP.
TCP port: Enter the TCP port to be monitored. When using ICMP pings this is not
needed.
Hostname: The name or IP address of the monitored network device.
Ping interval: Select the frequency (in seconds) at which the ping packet is sent to each
network device to check its operating status.
Ping retries: After this number of consecutive unanswered ping requests the device is
considered inactive.
Watchdog mode: When Reset port when host down is enabled, the Power Port is turned
off and switched back on after the time set in Reset Duration. In mode Switch off once
when host down the Power Port remains disabled.
At the default setting (Infinite wait for booting host after reset) the watchdog monitors the
connected device. When there is no longer a reply after a set time, the watchdog per-
forms the specified action, usually a reset of the Power Port. Now the watchdog waits
until the monitored device reports again on the network. This may take several minutes
depending on the boot duration of the device. Only when the device is accessible from
network again, the watchdog is re-armed. If the option Repeat reset on booting host after
x ping timeout is enabled, this mechanism is bypassed. Now the watchdog is re-activ-
ated after N Ping intervals (input field ping timeouts).
When enabling the IP master-slave mode, the port is switched depending on the availab-
ility of a remote device. Depending on the configuration, the port is switched on when the
terminal is reachable, or vice versa.
The option Repeat reset on booting host after x ping timeout has the following pitfall:
If a server, that is connected to the monitored Port is in need for a long boot process
(e.g. it is doing a file system check), the server would probably exceed the tripping time
of the watchdog. The server would be switched off and on again, and the file system
check is restarted. This would be repeated endlessly.