Coriolis meter now has Modbus interface
Published: 11 June 2012 - Michelle Lea
The communication capabilities of Yokogawa’s Rotamass 3 Coriolis flowmeter series have been extended by the addition of a Modbus interface. Modbus communications via an RS-485 connection will be available in both Modbus RTU and ASCII transmission modes.
Modbus communication is available at speeds up to 57 kbit/s and enables access to process measurements such as mass/flow, density and temperature. All measurement variables are included as readable address registers.
In addition, 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. The Rotamass still also offers standard I/O interfaces such as 4-20 mA, pulse/frequency and status in/out 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 unit. 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. Simultaneous HART communication via HHT or FDT is also possible.
The flowmeter’s ‘box in box’ design is said to guarantee decoupling of the device from external vibrations and stresses. With its two U-shaped and thick wall tubes, the device can achieve a measurement accuracy of ±0.1% of reading for liquids and ±0.5% for gases.