26
Note
: In the Analog Alarms channel you will be able to see if your analog alarm channel is enabled if you see
your description and "Yes" under the Enabled column.
Each of the NetGuardian 216 analog channels must be individually configured to monitor external analog data.
The Analog to Digital Converters (ADCs) support a range of -90 to +90 VDC. There are four alarm trip points
(thresholds) in ascending or descending order: major under, minor under, minor over, and major over.
You can choose the values for each of the thresholds on all channels. As with the other alarms, you can designate
whether or not to send an SNMP trap when a threshold is crossed — see section 9.1 (Reference Information)
Tables A.1 and A.2 for mapping information. You will see Yes for traps to be sent, or No for traps not to be sent,
in the Enabled column (default trap setting is Yes).
Note
: If you are in the Alarm Channel Off Mode, you can activate your analogs by entering descriptions,
however, you will not be able to designate whether or not to send an SNMP trap.
5.10.1 Current Sequencing
The thresholds for your analogs must be set from Under to Over in either ascending or descending potential (or
current) order. Thus the settings of -46, -47, -53, and -54 corresponding respectively to major under, minor under,
minor over and major over is valid.
The analog alarms are set to measure voltage by default and the thresholds are reported as actual units. To change
any one analog alarm to measure current instead, a circuit board jumper setting must be changed. Refer to section
4.7.2.1 (Jumper Options) for details on jumper locations and positions.
The analog threshold alarms can be entered in either ascending or descending order. This allows a low negative
voltage to be provisioned as either an under or over alarm to match the application context. In either case the
analog value between the minor over and minor under returns an alarm clear condition.
Voltage
Ascending Descending
0
8 9 MjO
MjU
– 43
1
2
7
MnO
MnU
– 45
3
6
MnU
MjO
– 58
MjU
MjO
– 60
4 5
Time
Point
Ascending
Descending
1
MnO – A
MnU – A
2
MnO – C
MnU – C
3
MnU – A
MnO – A
4
MjU – A
MjO – A
5
MjU – C
MjO – C
6
MnU – C
MnO – C
7
MnO – A
MnU – A
8
MjO – A
MjU – A
9
MjO – C
MjU – C
Key:
MnU
= Minor Under
A
= Alarm
MnO
= Minor Over
C
= Clear
MjU
= Major Under
MjO
= Major Over
Fig. 5.20
Illustration of analog voltage/current changes to threshold alarm