Thresholds define the accepted condition limits required to preserve the quality of your inventory or production environment. Threshold condition limits are saved as threshold alarm templates, and can be applied to one or more Locations. If condition limits are exceeded, viewLinc can activate an alarm, and, optionally, send one or more alarm notifications.
Threshold alarm templates define:
- Values associated with one or more conditions (Low-Low, Low, High, High-High, RoC, Alarm off margin).
- Color codes to reflect condition severity.
- One or more threshold alarm activation delays.
- Whether the alarm needs to be acknowledged.
You can apply one or more threshold templates to a Location, depending on how often you need to change threshold values, or how frequently you want to know about changing conditions.
You can also specify the alarm off margin so viewLinc will ignore condition changes within a specified temperature range and persist sending alarm notifications while conditions remain in this range.
Up to 5 threshold settings can be saved as a single template and then assigned to one or more Locations. If the settings are modified, the new settings apply to all Locations to which they have been assigned.
Example
If you have a monitored area that should remain between 10°C and 12°C, you could set up one or all of these levels:
- Low threshold set at 10.5 °C to warn when the temperature is close to the Low-Low threshold.
- Low-Low threshold set at 10 °C lasting for more than 1 minute to trigger specific alarm settings for the breach of the lower threshold.
- High threshold set at 11.5 °C to warn when the temperature is close to the High-High threshold.
- High-High threshold set at 12 °C lasting for more than 5 minutes to trigger specific alarm settings when upper threshold exceeded.
- Rate of Change set to 0.25 °C/min to warn when temperature increases or decreases rapidly.
Provisional threshold alarms
In rare cases in which the system is receiving real-time data but has delayed historical data that indicates a potential alarm condition, the system generates a provisional alarm. This alarm only occurs for RFL100 loggers and if a threshold alarm delay is set.
- disappear because the excursion was temporary, and conditions have returned to acceptable levels, or
- become a true threshold alarm because subsequent data confirmed that the excursion is persisting.
Provisional alarms are intended as proactive warnings to viewLinc users. Instead of waiting for confirmation of an alarm condition, which could be delayed by a communication problem, users can take action to immediately to check their physical setup for issues.
Rate-of-change alarms
difference_per_minute = (new_value-previous_value)/(time_difference_in_seconds/60) Do not use rate-of-change alarms with an alarm delay. An RoC alarm will only be
triggered if the threshold for the alarm continues past the duration of the delay. In the
following example, if the system has a 2-minute alarm delay, the significant 10° C
temperature change will not result in an alarm being triggered:
|