Connect Rs485 Communications - Hach 2200 PCX Basic User Manual

Connect RS485 communications

Set up an RS485 serial network to connect multiple instruments and a controlling computer. The total
distance from the RS485 signal converter to the farthest instrument can be a maximum of 1219.20 m
(4000 ft) without an amplifier/repeater. Refer to the steps that follow and to
instruments. Refer to
Items to collect: RS485-type shielded and a low capacitance twisted-pair cable (Belden 9841 or
equivalent), signal converter (RS485 to RS232 or RS485 to USB)
1. Install a RS485 cable between the signal converter and the first instrument. Refer to the signal
converter documentation for wiring instructions.
2. At the first instrument, put the cable through one electrical access port and then connect the blue
wire to the terminal lug with the "485B" label.
3. Connect the white wire to the terminal lug with the "485A" label.
4. Connect the shield cable to "SGND". Refer to the expanded manual on the manufacturer's
website for an optional junction box installation.
5. To connect another instrument to the system, put the cable through a second instrument to the
electrical access port of the second instrument.
6. Connect the blue wire to the terminal lug with the "485B" label at both ends of the cable.
7. Connect the white wire to the terminal lug with the "485A" label.
8. Shield to "SGND" at both ends of the cable.
9. Do steps 2 to 7 again to connect other instruments.
10. Set the jumper JP1 on the last instrument in the chain so that two pins are shorted together
(terminated). Refer to
Note: Keep the jumper JP1 open (not terminated) on all other instruments.
11. Close the covers and apply power to the instruments.
14 English
Prepare the wiring on page 13 for the wire preparation.
Figure 8, item 3.
Figure 8 to connect two