Contemporary Control Systems Compact Managed Switches Software Manual for Web Browser - Manual (Page 39)

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4.4.8 Configure Fault Relay
The switch has a relay output that can be used to signal the occurrence of one or more
events. The screen of Figure 34 has two panels — one for relay Settings and one to
Monitor Fault Condition — and shows that the relay can indicate the loss of a link or
presence of a link on one or many ports.
4.4.8.1 Settings
Port Monitoring (link monitoring of specific ports) can be either Enabled or Disabled.
Relay State determines the behaviour of the relay. By selecting “Make on Fault”, it will
close its contacts once a fault is detected. “Break on Fault” will cause the relay to normally
keep its contacts closed and open them upon detection of a fault. A fault is active when the
condition of a monitored link or port matches its monitored state (see 4.4.8.2).
Relay Automation Time After Startup specifies a port-monitoring delay which allows the
switch to stabilize for 1 to 999 seconds after startup. This is provided because, after
startup, several seconds may be required for the switch to complete auto-negotiation of the
data rate and duplex mode for each port. If the relay were not inhibited during this time, it
could repeatedly activate without a true fault existing.
Relay Reset Method is “Automatic” by default, but can be set to ”Manual”. In “Manual”
mode, clicking on “Clear Relay” will reset the relay.
4.4.8.2 Monitor Fault Condition
As displayed in Figure 34, the user can monitor three conditions on a port-by-port basis :
Ignore (the default) removes the port from link monitoring.
No Link (read only) reports a fault, (relay activated) if the link for the port has been lost.
Link Present (read only) reports a fault (relay activated) if a link has been detected on
the port. This option is commonly used as a security feature to detect unauthorized
connections to the switch.
Current Faults (read only) displays conditions when the screen first appears. While on
screen, this report is static; it will only be updated if the refresh option is selected.
After relay activation is noted, the fault should be corrected. If No Link monitoring is in
force, this will require restoration of a broken link or repair of the defective device to
which the switch is connected. On the other hand, if Link Present monitoring is in use,
removing the offending cable or end device will be required.
The
Status LED on the switch front panel displays a heartbeat blink every 5 seconds
during normal operation. If a fault occurs, it blinks every second — except that EIDX
models maintain the 5-second heartbeat and the LED turns red to indicate a fault.
The example of Figure 34 is for an 8-port model. Screens for 16- and 24-port models
would Function the same — but display more ports.
(upper panel)
(lower panel)