User's Manual

User’s Manual for Node C Network Elements
Page 74
M0121A1A_uc.doc
5.2.6 External Alarms
The external alarms are used to monitor the status of one or more external devices
via the Node C. A UPS or entry alarm is among the items that might be connected to
the contact relay and monitored via the Node C. The cage clamp connectors are
located on the distribution & alarm board of the Interface Unit.
Observe that the cross-sectional area of the wires to be connected must be in the
range from 0.5 - 1.0 mm
2
. Do not use wire-end sleeves (wire cable ends).
figure 5-4 Configuration of external alarm clamps
There are three external cage glands at the bottom of the Interface Unit, which may
be used to connect the external devices.
All external alarms are defaulted to high (5VDC) without connection. This setting may
be changed on the external alarm page to active high or active low. The severity
levels of the external alarms may be set via the web page. More information about
the external alarm settings is available in the web page and online-help.
When not all of the external alarms are required, make sure that the other alarms are
set to active low or disable the alarm; otherwise the status will always show an alarm.
The names for each external alarm are user-definable on the external alarm page
(see chapter 4.2.4.4 Alarm Management) and it is suggested that they be renamed to
indicate the use of these alarms.
Input voltage range 5VDC
Recommended input line Potential free
Nominal sink current to ground 15mA
Active level High or low set via software
Connectors Cage clamps