Owner's manual

QDR – QTech Digital Radio – Owners Manual – v1.3 – August 2012 9
www.qtech.co.nz Tel: [phone]
5.3 RS485 - Full Duplex Mode
This mode is used for serial data communications where all four signal lines are
required.
Jumper Settings for Full Duplex RS485 (4-Wire)
Refer to Section 6 for further details on the jumpers
Jumper Position
JP3 In
JP4 In
JP5 Out
JP6 Out
Pinout of RS485 Port when in Full Duplex Mode
Pin Signal Input/Output Description
1 GND - Ground
2 B Input Inverting Receiver Input
3 A Input Non inverting Receiver Input
4 Z Output Inverting Driver Output
5 Y Output Non inverting Driver Output
6 GND - Ground
Typical Full Duplex Connection
Note: Line termination resistors are inside the QDR
120 Ohm
120 Ohm
Y
Z
A
B
Y
A
B
Z
120 Ohm
120 Ohm