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WELL WATER LEVEL DATA LOGGING UNIT

CHALLENGE

To develop a data-recording tool for a major water company allowing them to monitor (and store) water levels in both artesian wells and above-ground storage tanks. Features and considerations are as follows:

• Remote monitoring and data access is not an option (no internet or wireless connection provisions).
• Data must be retrievable manually - having a laptop is not a guaranteed luxury.
• Must be capable of monitoring up to (6) water levels (via water level and/or pressure transducers, 4-20ma)
• Must have some means of configuration, allowing data to be stored as a meaningful value (depth/pressure) and not just current

SOLUTION

The Netburner PK70 with a Netburner multi-I/O blade board (NBPKBM-100CR).

These units are deployed in the field at numerous 'pump houses' where they are responsible for logging input data for (up to) (6) fluid level transducers. The actual number of inputs is configurable. These pump houses do not have the provision for internet access and the managing field technicians do not necessarily have access to a laptop for device connection. Therefore, each unit is required to provide some level of visual feedback to the user regarding its current operational state.

All collected data is stored as simple ASCII text to an on-board SD memory card. Additionally, each card comes with an initialization startup file containing information about the specific transducers connected to the A/D inputs of the data acquisition card (particularly gain and offset). The resulting stored values are in actual units (level or pressure, depending on the application).

Due to the lack of a user interface (no web interface, no laptop to monitor the device's state), the two on-board LED's were designed into the application and used to provide distinct feedback depending on a handful of possible states (data writing, card absent, card ready for removal, etc). A summary of these states and the corresponding LED behavior can be found below.

And finally, due to the fact that the PK70 does not have an on-board battery to retain state of time during power cycles, a simple algorithm was put in place to prevent corruption of already-written data in the event of power outages.