software may require the use of an RS-485 to RS-232 converter, as most PCs cannot be wired directly to RS-485.
To wire the RS-485 cable to the Base Radio we recommend using a 22AWG twisted pair shielded wire. Place one of the twisted pair wires in the “A” (Tx+/Rx+) slot of the same terminal block as the power supply wires, and the other wire in the “B” (Tx-/RX-) slot of the terminal block as shown below in Figure 3-5.
Figure 3-5 Wiring RS-485 to the Base Radio
RS-485 may be wired in-line (in series) to multiple Base Radios. This is called “daisy- chaining”. Only Base Radios using Modbus RS-485 output can be daisy-chained. See Section 3.2.6. Note that Base Radios daisy-chained must be set to different RF Channels to communicate properly on the same wire.
3.2.4 Wiring the RS-485/232 Converter to the Base Radio
Honeywell offers an optically isolated, surge protected, DIN Rail mountable RS-485/232 converter, AIC #. Because there are many RS-485/232 Converters available, please see your converter’s instruction manual for details as this section will only discuss the wiring of the B&B 485LDRC9 converter.
The Base Radio communicates via a RS-485 half-duplex differential signal with A being Tx+/Rx+ and B being Tx-/Rx-. To properly wire the Base Radio to the 485LDRC9, you should follow Figure 3-6.
| B ase R adio | 485LD R C 9 |
| C onverter |
| | | |
| A | | | H | (T D B ) |
| | |
| B | | | G | (T D A ) |
| | |
| | | | | | |
Figure 3-6 Base Radio to RS-232 Converter Wiring Diagram
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