Make A Hart/Bell 202 Connection - Emerson Micro Motion 2500 Configuration And Use Manual

A.2.3

Make a HART/Bell 202 connection

You can connect directly to the primary mA terminals on the transmitter, to any point in a
local HART loop, or to any point in a HART multidrop network.
CAUTION!
If you connect directly to the mA terminals, the transmitter's mA Output may be affected. If
you are using the mA Output for process control, set devices for manual control before
connecting directly to the mA terminals.
Prerequisites
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Procedure
1.
2.
Configuration and Use Manual
ProLink III is installed and licensed on your PC
One of the following:
- RS-232 to Bell 202 signal converter
- USB to Bell 202 signal converter
An available serial port or USB port
Adapters as required (for example, 9-pin to 25-pin)
Attach the signal converter to the serial port or USB port on your PC.
To connect directly to the transmitter terminals:
a. Connect the leads from the signal converter to terminals 21 and 22.
Tip
HART connections are not polarity-sensitive. It does not matter which lead you attach to
which terminal.
b. Add resistance as necessary to achieve at least one volt across the connection
points.
Important
HART/Bell 202 connections require a voltage drop of 1 VDC. To achieve this, add
resistance of 250–600 Ω to the connection.
Using ProLink III with the transmitter
201