The HART (Highway Addressable Remote Transducer) protocol is a widely used communication protocol in industrial automation. It is a hybrid analog and digital protocol, allowing for simultaneous transmission of analog and digital data over the same wiring. Developed in the 1980s, HART has become an industry standard for smart field devices.
HART enables two-way communication between smart devices and control systems or hand-held communicators. It enhances the capabilities of traditional 4-20 mA analog signals by superimposing digital communication signals on top of the analog signal, allowing for additional data exchange without disrupting the analog measurement.
HART communication works by superimposing a Frequency Shift Keying (FSK) signal on top of the 4-20 mA analog signal. The FSK signal uses two frequencies, 1200 Hz and 2200 Hz, to represent binary data (0 and 1, respectively). This digital signal does not interfere with the analog measurement, allowing both signals to coexist on the same wiring.
HART supports various commands for device configuration, data retrieval, and diagnostics. These commands are divided into three categories:
Universal commands are supported by all HART devices and include basic functions such as reading device information and process variables.
Common practice commands provide additional functionality that is commonly used but not universally supported by all devices.
Device-specific commands are unique to each device and provide access to specialized features and functions.
The HART (Highway Addressable Remote Transducer) protocol is a widely used communication protocol in industrial automation. It is a hybrid analog and digital protocol, allowing for simultaneous transmission of analog and digital data over the same wiring. Developed in the 1980s, HART has become an industry standard for smart field devices.
HART enables two-way communication between smart devices and control systems or hand-held communicators. It enhances the capabilities of traditional 4-20 mA analog signals by superimposing digital communication signals on top of the analog signal, allowing for additional data exchange without disrupting the analog measurement.
HART communication works by superimposing a Frequency Shift Keying (FSK) signal on top of the 4-20 mA analog signal. The FSK signal uses two frequencies, 1200 Hz and 2200 Hz, to represent binary data (0 and 1, respectively). This digital signal does not interfere with the analog measurement, allowing both signals to coexist on the same wiring.
HART supports various commands for device configuration, data retrieval, and diagnostics. These commands are divided into three categories:
Universal commands are supported by all HART devices and include basic functions such as reading device information and process variables.
Common practice commands provide additional functionality that is commonly used but not universally supported by all devices.
Device-specific commands are unique to each device and provide access to specialized features and functions.