NOVUS V1.5x A - Manual (Page 89)

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ALARMS
32 alarms are available in each FieldLogger. Each alarm requires you to choose a channel, a condition, a set point and
hysteresis. When the alarm condition is met (example: Channel_1 > 45.0 º C), an event is generated for which different
actions can be associated. For each selected channel, its current value is used in the comparison. In case of digital
channels, we will use the values associated with two logical states. When one channel is in error, the configured error
value will be used in the alarm. The value of the channel to be used will always be the floating point value.
The available conditions are:
• Greater than (>): Alarm condition is met when the selected channel is greater than the set point.
• Greater than or equal (>=): Alarm condition is met when the selected channel is greater or equal to the set point.
• Minor (<): Alarm condition is met when the selected channel is minor than the set point.
• Minor than or equal (<=): Alarm condition is met when the selected channel is minor or equal to the set point.
• Equal (==): Alarm condition is met when the selected channel is equal to the set point. With this condition,
hysteresis does not make much sense and should be maintained at "0.0". Analog channels can hardly have a
value exactly equal to the set point value, so you should avoid this condition with analog channels, because it will
be an alarm condition that might never be satisfied.
• Different (!=): Alarm condition is met when the selected channel is different from the set point. With this condition,
hysteresis does not make much sense and should be maintained at "0.0". Analog channels can hardly have a
value exactly equal to the set point value, so you should avoid this condition with analog channels, because it will
be an alarm condition that might always be satisfied.
Available actions are:
• Activating the relays (they must have been configured to "activation by alarm" in the Configuration software).
• Activating the digital outputs (they must have been configured to "activation by alarm" in the Configuration
software).
• Loggings start: when reaching the alarm condition, starts loggings if they are not already logging.
• Loggings stops: when reaching the alarm condition, stops loggings if they are not already stopped.
• Loggings start and stop: logs while the alarm condition is met.
• Sending e-mails: allows sending an e-mail reporting the alarm condition to up to 10 receivers (they must have
been enclosed in the receivers list of the equipment).
• Sending SNMP traps: sends a trap to the configured server with a number regarding the index of the alarm.
Sending e-mails depends on the availability of TCP connections on the part of the FieldLogger (it has a limit of
simultaneous connections, see the chapter Specifications). Sending traps depends on the availability of UDP
connections on the part of the FieldLogger (it has a limit of simultaneous connections, see the chapter Specifications).
Just one alarm can start loggings, and just one alarm can stop them. In case you configure the start and/or stop of the
logging for alarms, there is no option of “circular memory”, that is, loggings will terminate as soon as the loggings
available memory gets full.
The alarm condition must stay at least 250 ms in order to ensure that it is detected. In the same way, the output of the
alarm condition must remain the least 250 ms in order to guarantee that it is detected. Besides, you should remember
that the analog channels can have a delay in the measurement of the true input value, depending on the sensor type, on
the interval between readings and the configured filter, among others. The remote channels, in turn, depend directly on
the set scan interval. Thus, these types of channels in particular can offer an additional latency in the detection of the
alarm condition.
When powering FieldLogger up, there are no reliable values in the channels. In case of the analog and remote
channels, you should wait for the first scan to be done for valid values to be available. So, alarms that use these kinds of
channels may take a while until they are ready to compare with the configured set point. Particularly when using remote
channels, a complete scan may take several seconds.