Coriolis with Modbus

Yokogawa has extended the communication capabilities of the well-proven ROTAMASS 3 Coriolis flowmeter series by adding a Modbus interface. Modbus communications via an RS-485 connection will be available in both Modbus RTU and ASCII transmission modes.

The fast and simple Modbus communication at up to 57 kbit/s enables access to all relevant process measurements including - but not limited to - mass/flow, density and temperature.. All measurement variables are included as readable address registers.

Compared to other field communication protocols like FOUNDATION Fieldbus or Profibus, the Modbus protocol involves no costly changes to the conventional 4-20 mA wiring, allowing a point-to-point or multi-drop network to be realised with minimal effort.

In addition to the Modbus communication, the standard I/O interfaces such as 4-20 mA, pulse/frequency and status in/out are still available for control and/or monitoring purposes.

For easy configuration of meter measurements and settings, a free ROTAMASS Modbus communication tool will be delivered with each ROTAMASS. This software tool is equipped with different functions, clearly shown in an explorer view. Despite Modbus communication, all settings can be done by means of the indicator. Even simultaneous HART communication via HHT or FDT is possible.

The ROTAMASS Coriolis flowmeter is respected in the market for its superior "box in box" design, which guarantees decoupling of the device from external vibrations and stresses. With its two U-shaped and thick wall tubes, this device achieves an optimum measurement accuracy of ±0.1% of reading for liquids and ±0.5% for gases, and has excellent zero-point stability, even under tough conditions in the field.

The mass-flow measurement range of the ROTAMASS spans from 45 kg/h to 600 t/h. A unique density accuracy of ±0.0005 g/cm3 (±0.5 g/l) results from the real density being calibrated using different liquids and temperatures. ROTAMASS can handle applications involving temperatures from -200°C up to +350°C.

Every ROTAMASS model is available with a variety of process connections offering pressure rates up to 285 bar. The result is a range of instruments to suit every customer in terms of pressure loss, measurement accuracy and price.

ROTAMASS with Modbus and its user-friendly communication tool is the ideal solution for multivariable process measure in a wide range of applications.