User Manual

DESCRIPTION OF HART INTERFACE 9
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9.3 Connection variants
The signal converter is a 2-wire device with 4...20 mA current output and HART
®
interface.
• Multi-Drop Mode is supported
Multi-Drop Mode is supportedMulti-Drop Mode is supported
Multi-Drop Mode is supported
In a Multi-Drop communication system, more than 1 device is connected to a common
transmission cable.
• Burst Mode is not supported
Burst Mode is not supportedBurst Mode is not supported
Burst Mode is not supported
There are two ways of using the HART
®
communication:
• as Point-to-Point connection and
• as Multi-Drop connection with 2-wire connection.
9.3.1 Point-to-Point connection - analogue / digital mode
Point-to-Point connection between the signal converter and the HART® Master.
The current output of the device is passive.
Also.
9.3.2 Multi-Drop connection (2-wire connection)
For an illustration of multi-drop networks.
9.4 HART® device variables
The HART® dynamic variables PV (Primary Variable), SV (Secondary Variable), TV (Third Variable)
and QV (Fourth Variable) can be assigned to any of the device variables.
The HART® dynamic variable PV is always connected to the HART® current output which is, for
example, assigned to level measurement.
9.5 Field Communicator 475 (FC 475)
The Field Communicator is a hand terminal from Emerson Process Management that is
designed to configure HART® and Foundation Fieldbus devices. Device Descriptions (DDs) are
used to integrate different devices into the Field Communicator.
9.5.1 Installation
System and software requirements for the Field Communicator
• System card that includes the "Easy Upgrade Option"
• Field Communicator Easy Upgrade Programming Utility
• HART
®
Device Description file
CAUTION!
The Field Communicator cannot be used to correctly configure, operate or read data from the
device unless the Device Description (DD) file is installed.