Today, Alicat is shipping our first instruments equipped with Modbus-RTU, an industrial communications protocol that we now offer as an option on all of our mass flow meters, mass flow controllers and pressure controllers. Modbus-RTU is an enduring industrial networking standard that allows communication among hundreds of devices on a single network. This application layer messaging protocol rides on top of other communications protocols like RS-232 and RS-485. Modbus data may be transmitted through Alicat’s default 8-pin mini-DIN connector, a 9-pin or 15-pin D-Sub connector or an RJ45 connector.
Alicat’s new Modbus implementation brings our signature laminar differential pressure-based measurement and 50-ms proportional control speeds to existing industrial Modbus-RTU networks. The Modbus protocol outputs all of the mass flow or pressure controller’s data, including: mass flow, volumetric flow, pressure, temperature, selected gas calibration, setpoint and totalized flow. Users may send commanded setpoints, gas selections and register changes to the Alicat meter or controller using a Modbus-enabled computer or PLC.
This Modbus offering may be paired with either Alicat’s standard multi-drop RS-232 connectivity or the optional RS-485 for greater data integrity over longer distances. Physical connector choices include 8-pin mini-DIN, 9-pin D-sub and 15-pin D-sub, which are available in a variety of pinout configurations for easy drop-in replacement of older industrial units. All Alicat instruments are backed by NIST-traceable calibration, comprehensive technical support and a lifetime warranty.