Applied Motion STM17C-3CE - Manual (Page 14)

RS-422/485 Connector diagram
Four-Wire Configuration
Four-wire Systems utilize separate transmit and receive wires. One pair of wires must connect the host’s transmit signals to
each drive’s RX+ and RX- terminals. The other pair connects the drive’s TX+ and TX- terminals to the host’s receive signals.
A logic ground terminal is provided on each drive and can be used to keep all drives at the same ground potential.
This terminal connects internally to the DC power supply return (V-), so if all the drives on the RS-422/485 network are
powered from the same supply it is not necessary to connect the logic grounds. One drive’s GND terminal should still be
connected to the host computer ground.
RS-422/485 4–wire system
NOTE: a 120 ohm terminating resistor is required at the end of a four wire network.
NOTE: If the PC does not have an RS-422/485 serial port, a converter will be required.
GND (circuit ground)
TX-
TX+
RX-
RX+
+Rx- +Tx- GND +Rx- +Tx- GND +Rx- +Tx- GND
to Host Tx+
to Host Tx-
to Host Rx+
to Host Rx-
to Host GND
Drive 1 Drive 2 Drive n
120
14
STM17 Hardware Manual
920-0034 rev A
9/30/2010