Encoder MDT: Precision Water Metering for Encoder-Based Systems

Encoder MDT transmits readings wirelessly via radio to the DCAP or Gateway. The MDT initiates a digital handshake with the meter, which responds with its current reading and serial number. Depending on the meter type, additional details such as unit of measure, count factor, and hot/cold designation may also be included.

Encoder MDT can communicate over distances of up to 1 mile in Standard Range, up to 10 miles in MAX Range, and more than 10 miles in LoRaWAN Range.

Encoder MDT operates on two field-replaceable AA batteries, providing a lifespan of 6–8 years. Even when switched off, it wakes every 24 hours to check for a connected meter; if a valid response is received, it powers on and begins transmitting reads.

Encoder MDT can be configured with either a single input for a standalone meter or dual inputs for co-located setups, such as monitoring hot and cold water meters.

The count factor may be printed on the register face (e.g., ×10, ×100), inferred from the number of fixed zeros, or indicated by a graphic showing which digits are available for reading. For electronic meters, this varies: Neptune outputs only the upper six digits, while Kamstrup meters output all digits shown. Confirm with the meter manufacturer when in doubt.

Encoder MDT transmits absolute readings to the DCAP or Gateway via radio, ensuring timely and accurate data delivery for efficient utility management. It interprets meter responses in encoded formats such as Sensus UI-1203, Neptune, or GWF AllRead.

On Neptune ProRead mechanical meters, 1" and smaller sizes provide six moving dials plus one fixed zero (count factor 10). Larger 1.5"–2" sizes add two fixed zeros (count factor 100). Due to output restrictions, the MDT only detects changes every 50 or 500 gallons, respectively. Neptune E-Coder and ProCoder meters output more digits: older MDTs (firmware before 2.11F) read six digits, while newer MDTs (2.11F and later) read eight. Depending on meter size, count factors range from 0.1 to 100.

Newer solid-state LCD registers typically provide higher resolution. Some limit output to upper digits only (e.g., four digits with count factor 1000), while others provide full output (e.g., eight digits with count factor 0.001 m³).

Resolution depends on how the meter is manufactured or programmed. Some provide dial values down to 1/100 unit, while others output only a subset. For example, a meter with eight dials may provide only four through the interface. In this case, a register reading of 729.62 cubic feet would be reported by the MDT as 700 (with a 100× count factor) until the register reaches 800.

Mechanical meters use magnetic or optical mechanisms to capture dial positions. When queried, the MDT energizes the circuit and receives the output data. To reduce complexity, many meters limit or reduce resolution of the rightmost dials. High-resolution sweep hands are never available via encoded outputs.

Consult the meter manufacturer’s instructions for specific guidance. In general, only the digits provided through the encoded interface should be used, with fixed zeros added where applicable.