NI monitoring devices can intelligently log data based on a configuration specified by the user, reducing the overall data volume and providing a means to isolate important asset events. This intelligent logging can be triggered by a few events:
- Time, or periodic, capture: Data is captured in user-configurable regular time intervals such as once an hour, once a day, three times a day, and so on. This capture provides information to understand the historical trends of the asset.
- Change in delta engineering units (EU): Data is captured when one or more conditions, such as vibration level, temperature, or spectral band, change by at least a specified amount. Both positive and negative changes in value cause a delta EU trigger to occur. The “baseline” level is first set on startup of the NI monitoring device and will reset when a delta EU trigger occurs. This captures provides context surrounding sudden changes in asset health data that may be important for review.
- Alarm: When an alarm is generated, a data file will always be captured to allow an asset expert to examine the conditions that surround the alarm condition.
- Force trigger: This trigger is initiated from various points in the NI InsightCM software. Data collected by a force trigger is useful when there is a need to observe the state of the asset in response to a previous alarm or other report of an issue.
When a data file trigger occurs, the waveform data leading up to the event and immediately after the event is stored, along with the calculated feature information in a single, publicly documented TDMS data file. This data file is then sent to NI InsightCM through the network connection to make the data available for review and to execute further processing. Having access to the data leading up to an event is often the most critical and helps subject matter experts better understand what caused the event. If no network connection is available when a data file trigger occurs, the NI monitoring device will store the data locally, with enough storage to remain disconnected for up to several months depending on configuration parameters, and continue to monitor the asset using the saved configuration. Upon reconnection to the server, any locally stored data will be forwarded to the server.
Data groups allow for device channels to share acquisition properties and to store the raw data and features together in a single data file. If multiple assets are being monitored with a single NI monitoring device, data groups allow for the grouping of acquisition, analysis, and file collection settings for each asset’s sensors. For example, multiple motors could be monitored using a single NI monitoring device. Having a separate data group for each motor will ensure that all the data associated with a single motor is stored together and can be easily analyzed individually without collecting unnecessary data from other motors.
Specifying operating states for data groups allows NI monitoring devices to dynamically switch between data collection behaviors. For example, an asset under a heavy load might require data to be collected more frequently. By defining an operating state based on a vibration RMS threshold (signifying increased load), the NI monitoring device can acquire data more often to provide additional context about the health of the asset. The conditions to enter or exit an operating state automatically can be based on features or time.
Sensory data provides a significant amount of context regarding asset health, but making correlations sometimes requires process information. NI monitoring devices have the ability to serve as a Modbus master to read information from third-party slave devices via Modbus TCP or Modbus RTU (Serial). Data from Modbus channels can be used as a source for delta EU triggers, operating state transitions, and for alarm condition evaluation. This data is made available for trending and correlation along with sensory data in NI InsightCM .