HART communication*1 is a means of transmitting multiple signals by superimposing long-standard 4-20 mA DC analog signals on digital signals.
The figure below is an example of connecting field instruments and upstream devices using HART communication compatible VJA1/H, VJH1/HC signal conditioners. With these signal conditioners, you can output analog control signals as well as TAG and other measuring information from the field instruments to the upstream devices, and at the same time output analog signals to recorders and other monitoring devices. Additionally, the upstream devices can perform zero point/span adjustment and set various parameters on the output devices in the field (HART communication enabled control valves, etc.).
Note: This requires that the devices on both the field and DCS sides can send and receive HART signals, and the parameters that can be set depends on the specifications of the devices performing HART communication.
*The above configuration also allows for D-series nest-housed converters (DA7, DC7).
*1: HART stands for "highway addressable remote transducer."
HART was put forward by Fisher-Rosemount Corp. (USA) as an open standard for industrial control field networks. There is currently an organization called the HCF (HART Communication Foundation). Used extensively throughout the world, the standard defines a communication protocol through which digital signals are superimposed on analog signals, and transmitted.
Products
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Compact Plug-in Type JUXTA VJ Series |
Compact Plug-in Type JUXTA VJ Series
- Compact design for space saving
- Universal input
- Comes standard with 2 isolated current outputs (4–20 mA DC/4–20 mA DC)
- Globally compatible power supply (85–264 VAC/DC, 12–36 VDC)
- Standard withstand voltage of 2000 V
- Compliance with international safety standards
- Relaying HART communication signals (VJA1/H, VJH1/HC)
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| Nest Type for DCS JUXTA D Series |
Nest Type for DCS JUXTA D Series
- High affinity with DCS systems
- Easily maintainable card format
- Mixed mounting of Electronic and Pneumatic signal conditioners
- Designed to minimize usage of aluminum electrolyte capacitors
- Standard second output
- Relaying HART communication signals (DA7, DC7)
Industrien
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Upstream
The upstream industry includes offshore and onshore activities including wellhead automation, fractionation, completion, and separation to recover and prepare underground or underwater crude oil and natural gas.
As petroleum is brought to the surface, it must be separated prior to transport. Primary and secondary separation stages commonly distribute gas flow, water flow, and oil flow in three phase separation. Gas movement requires pipeline and can include a fractionation process in the upstream stage prior to movement. Liquids can be placed into a tanks or pipelines and sent for processing, requiring accurate level measurements.