Industrial instrumentation has undergone significant advancements over the past few decades, when the majority of instruments were limited to simple 4-20 or 0-20mA analog output proportional to the process variable. The process variable was converted to a dedicated analog signal transmitted from the instrument over 2-wire to an indicator or control system, with a multi-drop configuration, requiring direct access for manual adjustments by maintenance personnel.
The potential benefits of digital technology in instrumentation have been recognized subsequently. There could be a wealth of valuable data and functions contained in an instrument, such as device configuration, alarm limits, operating time & conditions, diagnostic information, etc. Obtaining such data helps optimize the operation of the device, and eventually improves process performance. HART protocol emerged as one of the early approaches to access this stranded data to make instruments intelligent.
HART technology allows communication with an analog instrument using a digital communication signal transmitted over the same 2-wire as the analog output. This digital signal provided 2-way communications between the instrument and a host without disrupting the output, facilitating access to various pieces of data. With HART, personnel can communicate with a transmitter and perform configuration or diagnostics while it is performing real-time process measurement.
WangYuan WP421A High Temperature Pressure Transmitter With 4~20mA + HART Protocol Output
Simultaneously, development of the other digital technologies was also underway that would be transmitted over dedicated communication highways, each offering specific benefits, including the representative Fieldbus technology of Modbus protocol with RS-485 interface. Modbus is a serial master-slave open protocol, allowing any manufacturer to integrate the protocol into an instrument, to provide local access to smart instruments from host systems.
WangYuan WP401A Pressure Transmitter With RS485 Modbus Output & Ex-proof
Thanks to technology advances over the past half century, instrument transmission has evolved from solely the primary process variable to a wealth of information available extending up to enterprise level. In the future, digital technology will continue to provide more details from transmitters, with a wider range of access approaches.
At WangYuan, a Chinese manufacturer with over 20 years extensive experience in the field of instrumentation, we prioritize the application of smart communication outputs for products of measurement instrument. Most of our products for measuring pressure, level, temperature and flow accept customization on signal output including foundation-registered HART Protocol and RS-485 Modbus to cater to users’ demands and field condition.
Post time: Mar-25-2024