•
For long-distance communication, or if noise from an external source interferes with the signal,
install 120-Ω
½
-W terminating resistors in parallel with the output at both ends of the
communication segment.
•
Ensure that there is no concurrent Modbus communication to the transmitter.
B.2.4 Make a HART/RS-485 connection from ProLink III to the
transmitter
This connection type uses HART protocol and commands to communicate with the transmitter over an
RS-485 network. You can connect directly to the RS/485 terminals on your transmitter (Channel E) or to any
point on the network.
Prerequisites
•
Channel E activated on the transmitter
•
Installation kit
•
An available serial port or USB port
•
Adapters as required (for example, 9-pin to 25-pin)
Procedure
1. Attach the signal converter to the serial port or USB port on your PC.
2. To connect directly to the transmitter terminals:
a) Open the transmitter wiring compartment.
CAUTION
If the transmitter is in a hazardous area, do not open the wiring compartment while the
transmitter is powered up. Opening the wiring compartment while the transmitter is
powered up could cause an explosion. To connect to the transmitter in a hazardous
environment, use a connection method that does not require opening the wiring
compartment.
b) Connect the leads from the signal converter to terminals 9 (RS-485/A) and 10 (RS-485/B).
Tip
Usually, but not always, the black lead is RS-485/A and the red lead is RS-485/B.
Using ProLink III with the transmitter
Configuration and Use Manual
March 2019
MMI-20025166
322
Micro Motion Model 5700 Transmitters with Configurable Outputs