Filter
Top Products
Installation and Use Manual 19
Installation and Setup
ProLink II Setup Transmitter StartupUsing ProLink IIBefore You Begin
Method 5: HART/RS-485 temporary or hard-wired connection to transmitter or multidrop network
Note: This method is supported by RFT9739 and RFT9712 transmitters, by Model 1700/2700
transmitters with the analog outputs option board, and Series 3000 transmitters.
Using a Black Box signal converter, the PC can be connected directly to a transmitter’s RS-485
terminals, to the output wires from these terminals, or to any point on a multidrop network. Figure 2-6
shows the wiring for this connection type.
1. Ensure that your transmitter’s RS-485 terminals are configured for HART protocol. See the
transmitter manual for instructions.
2. If you are using an RFT9712 transmitter, you must set a jumper on the transmitter for RS-485
communications. See the transmitter manual for instructions.
3. At the PC, attach the Black Box signal converter to the PC’s serial or USB port, using a 25-pin
to 9-pin adapter if necessary. Ensure that the positive and negative wires are connected as
shown in Table 2-9 and Figure 2-6.
4. Attach the other end of the signal converter leads:
• To any point on the network (hard-wired connection)
• Directly to the RS-485 terminals on your transmitter (temporary connection). See
Table 2-9
• To the output wires from the RS-485 terminals on your transmitter (hard-wired
connection). See Table 2-9
For assistance in identifying the RS-485 terminals, see Appendix A.
5. For long-distance communication, or if noise from an external source interferes with the
signal, add two 120-Ω terminating resistors (R1) at each end of the RS-485 network.
Table 2-9 Lead-to-terminal assignments – Method 5
Transmitter
Terminals
RS-485/A RS-485/B
Model 1700/2700 AN 5 6
Series 3000 panel-mount with screw-type connectors a32 c32
Series 3000 panel-mount with I/O cables 25 24
Series 3000 rack-mount a32 c32
Series 3000 field-mount 12 11
RFT9712 21 22
RFT9739 field-mount 27 26
RFT9739 rack-mount Z22 D22