User manual

Network-Enabled M Series Rack PDU User Manual
- 49 -
Defaults- Open/Close Contacts
Normal State
Normal state specifies the condition in which a contact is
considered to be ‘Normal’, ‘Non-alarmed’ state. Devices
such as smoke alarms and air conditioning units often have
normally open contacts. In order to receive alarm indic-
ations from these types of units, setting normally open
would cause alarms to be issued when the monitored con-
tact closes. Setting normally closed, in the case of a rack
cabinet door, would cause an alarm condition when the
door was opened.
Trap Alarm Level
Rather than using [Upper|Lower] [Control|Warning] Limit
settings, the Open/Close Contact sensors provide a Trap
Alarm Level drop down menu with the following options:
l Disabled
l Critical
l Warning
l Information
When the Trigger Type state occurs, if the Trap Alarm
Level is not Disabled, a trap with the given Trap Alarm
Level string content is generated.
Trigger Types
Trigger type defaults for Open/Close sensors are specified
here. The three available options for trigger types are:
Level
Level triggering is the default mode. When an input phys-
ically transitions from a Normal to Non-Normal state an
alarm will be triggered. However the alarm will only persist
while the input remains in a Non-Normal state. When the
input returns to a normal state the alarm will be cleared.
Normal to Non-Normal (Positive Edge)
This type of triggering may be used in situations where a
momentary type input (e.g. shock sensor, PIR etc.), is used.
Since these types of inputs are momentary any alarm con-
dition which occurs, no matter how short, will persist until
manually cleared. Positive Edge triggering is used when