Emerson FB3000, Instruction Manual

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Emerson FB3000 RTU Instruction Manual
D301851X012
May 2022
I/O Configuration and Wiring 49
Table 3-7: HART Characteristics
Type
Number
Supported
Characteristics
HART channel 1 to 4 An individual HART channel can be configured in
FBxConnect as either an input or an output, but not both.
A HART input supports either point-to-point or multi-drop
mode
A HART output supports only point-to-point mode; in multi-
drop mode, there is no analog signal output available.
3.6.1 Wiring the 3HRT04 Module
You can wire HART channels for different modes of operation.
3.6.1.1 Point-to-Point Mode
In Point-to-Point mode, the HART link allows both a 4-20mA analog current mode signal
as well as the modulated HART digital signal riding on top of it. Depending upon the
HART device connected, you can configure the channel as an AI (which means the 250-
ohm resistor is enabled) or an AO (which means the 250-ohm resistor is disabled).
Figure 3-10 shows how to wire all four HART channels in point-to-point mode. In this
case, each HART channel only communicates to a single HART device. You choose
whether a given channel serves as an input or output in FBxConnect. The 24V internal
loop power supply powers the HART devices. The HART interface only sinks current, it
cannot source current. As an output, each channel simultaneously provides an analog
current signal output (sink current only at 4-20 mA) and a HART signal modulated on top
of it.
Figure 3-10: HART Wiring – Point-to-Point Mode
HD HART Device