ABB M4M 30, User Manual

Page: 50 / 84

50
M4M 30
NETWORK ANALYZER USER MANUAL
7.5.Alarms
In this section it is possible to configure the single alarms, allowing to monitor certain value selected from a
list of parameters.
→ →
Alarms
When specific conditions are met, alarms is turned on or off. Triggering of alarms can be registered in the
devices notifications log, in the alarms section. In addition to that, they can be set up to control digital
outputs of the device. In order to set an output as alarm output, please refer to chapter “7.4.Input /
output”.
There are two types of alarms available on M4M: simple alarms and complex alarms. For complex alarms,
please refer to chapter “7.6.Complex alarms”.
Up to 25 simple alarms can be configured in the device. The following graph explains how the alarm
features work in relationship to threshold, delay, hysteresis.
How the alarm is turned on: Whenever measured value crosses threshold for a time that is higher than
the defined delay, timer is set and starts counting down delay. If count down is finished and the value
have not crossed back the threshold, alarm is turned on. At this point, according to configuration, alarms
trip is registered in the notifications log (alarm section) and/or alarm output is set High.
How the alarm is turned off: The alarm state is held until the value crosses turn off threshold, which is
the difference between the threshold and the threshold hysteresis. Crossing turn off threshold results
in turning off the alarm, thus digital output is turned off or/and it is registered in the notifications log
(alarm section).