Instruction manual

Troubleshooting

continued

RFT9739 Rack-Mount Transmitter Instruction Manual

Before You Begin Getting Started Mounting

Power-Supply and

Sensor Wiring

Output Wiring Startup Troubleshooting

Figure 7-1. HART

Communicator, ProLink

PC-Interface, and AMS modem connections

1. If necessary, add resistance in the loop by installing resistor R1. SMART FAMILY

devices require a minimum loop

resistance of 250 ohms. Loop resistance must not exceed 1000 ohms, regardless of the communication setup.

2. The DCS or PLC must be configured for an active milliamp signal.

3. Resistor R3 is required if the DCS or PLC does not have an internal resistor.

CAUTION

Connecting a HART device to the RFT9739 primary variable milliamp output loop could cause transmitter

output error.

If the primary variable (PV) analog output is being used for flow control, connecting a HART device to the output

loop could cause the transmitter 4-20 mA output to change, which would affect flow control devices.

Set control devices for manual operation before connecting a HART device to the RFT9739 primary variable

milliamp output loop.

Rack-mount

RFT9739

HART socket

(same circuit as

PV terminals)

(Note 3)

(Note 1)

DCS or PLC

with internal

resistor

(Note 2)

HART

Communicator,

ProLink PCI,

or AMS modem

PV+

PV–

HART socket or

PV terminals