Auto-Wake Function for Data Acquisition (DAQ), Machine Condition Monitoring, and Vibration Analysis
Data Acquisition Systems (DAQ’s) are commonly used to collect data to process and reveal information from captured signals. The applications may range anywhere from capturing seismic vibration data to sound measurements within stadiums. Depending on the application, researchers may be interested in monitoring the behavior of machines over a large time interval or in capturing data from specific events.
The auto-wake feature is a new and powerful function provided in EDM 10.0 software. This feature allows users to set up a wake-up alarm for Spiders to power on, perform a test, and power off. Users can upload up to 8 predefined tests and run these in Black Box mode (without a connection to a computer or network to run). This convenient mode allows users to acquire data autonomously or with little user intervention.
Figure 1. Predefined tests that can be uploaded on the front-end of the Spider system
Figure 2. Predefined tests stored on the front-end of the Spider system
All Spider systems can run in Black Box mode, users simply need to select the test to perform once the Spider is powered on. A real-time clock module contained inside the Spider system stores the date and time, allowing users to schedule the system to power on and power off. Furthermore, the Spiders can be programmed to run on a periodic schedule, eliminating the need to reconfigure a wake-up alarm after every test.
Figure 3. Test to be performed upon powering the Spider system
Figure 4. Auto-wake feature on the Spider-20 models
The Spider-20 system includes internal batteries to power on the system even when disconnected from an external power source. The Spider-20 can run for 6 hours with the batteries alone, which allows users to acquire data in the event of a power outage.
Additionally, this feature can conserve power. Consider a scenario where a researcher is capturing seismic data near railroads as trains are passing. It would be wasteful to keep a DAQ powered on while trains are not nearby. With the auto-wake function users can set the Spider to power on based on the train schedule. Using this setup, the Spider would be active and collecting data when a train passes and would power off during uneventful parts of the day. This not only saves a considerable amount of power, but quite a bit of internal memory.
The auto-wake feature is also applicable in machine condition monitoring. Vibrational analysis is a popular technique used to diagnose the health of structures and machinery with rotating components. It is common to obtain the vibrational frequency spectra of a machine in its new state as a baseline measurement, and then observe the changes of this spectra over time, which can reveal degradation and indicate possible failure ahead of time. With the auto-wake feature, a Spider-20 can be programmed to power on, acquire vibrational frequency data, and power off at specified intervals over several months or years. The user can then observe how their measurements have varied over time and perform a diagnosis either manually or through Crystal Instrument’s Vibration Diagnosis System (VDS).
Figure 5. APS collected based on wake-up schedule at different times during the day
Figure 6. Machine status report over time