Network Connections; Rs485 Connections; Terminator - Hach 9186 Instrument Manual

Modbus Communication

8.6 Network Connections

8.6.1 RS485 Connections

8.6.2 Terminator

8.6.3 Network Cable
8.6.4 RS232 to RS485 Converter
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The 9186 uses RS485 digital communications. RS485 is multi-drop network,
meaning multiple devices can be "daisy chained" on a single pair of wires.
Table 23 lists the connections to the RS485 network.
Connector Pin
K101 1
K101 2
K9 1 or 2
To preventing "ringing" on the RS485 network, a terminator jumper is provided on
the RS485 interface board, next to connector K101. The terminator should be
enabled on the last device on the network. Set the jumper as follows:
Position 0—Terminator disabled
Position 1—Terminator enabled (last device on RS485 network)
The recommended wire is a two-wire shielded RS485 communication cable.
Hach Catalog Number
57012-00
An optional RS232 to RS485 converter may be required to convert the RS485
signal to RS232 on Programmable Logic Controllers (PLC) or Personal
Computers (PC). Only one converter is required for each RS485 network.
Hach Catalog Number
57378-00
57379-00
Table 23 RS485 Connections
Function
Data (+)
Data (–)
GND
Belden Part Number
9841
Description
Isolated RS232 to RS485 converter, 115 V ac
Isolated RS232 to RS485 converter, 230 V ac
57012-00 Wire Color
Blue
White
Shield
Cable Type
2-wire Shielded