HART communication with the DeltaV system

The HART information is communicated digitally and is very helpful for device diagnostics. This information can be used in the DeltaV system to affect control strategy or to alert operators to a transmitter malfunction.

The DeltaV system communicates with HART devices through the following channels:

• HART analog input

• HART analog output

The HART analog input channel communicates the following values:

• Analog - raw 4 to 20 mA signal, Card and channel status are applied, no HART status is applied.

  • Field value, in percent (FIELD_VAL_PCT)

• Hybrid - 4 to 20 mA signal, Card, Channel, and HART status are applied.

  • Field value, in engineering units (HART_FIELD_VAL)

• HART Dynamic Variables - digital signal, Card, Channel, and HART status are applied.

  • Primary Variable, in engineering units (HART_PV)

  • Secondary Variable, in engineering units (HART_SV)

  • Tertiary Variable, in engineering units (HART_TV)

  • Fourth Variable, in engineering units (HART_FV)

The HART analog output channel communicates the following values:

• Hybrid - 4 to 20 mA signal, Card, Channel, and HART status are applied.

  • Field value, in engineering units (OUT)

• HART Dynamic Variables - digital signal, Card, Channel, and HART status are applied.

  • Primary Variable, in engineering units (HART_PV)

  • Secondary Variable, in engineering units (HART_SV)

  • Tertiary Variable, in engineering units (HART_TV)

  • Fourth Variable, in engineering units (HART_FV)

• HART Device Variables - digital signal, Card, Channel, and HART status are applied.

  • Slot 0 device variable, in engineering units (HART DV SLOT0)

  • Slot 1 device variable, in engineering units (HART DV SLOT1)

  • Slot 2 device variable, in engineering units (HART DV SLOT2)

  • Slot 3 device variable, in engineering units (HART DV SLOT3)

Some multivariable devices have a predefined set of Dynamic Variables; in others, you can assign process values to the Dynamic Variables through an external device or application. Refer to the vendor's documentation for your HART device for specific information. Link initialization contains information on setting up the devices to communicate correctly with the DeltaV system.