Applied Motion SV7-C-CE - Manual (Page 19)

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SV7 Hardware Manual 920-0012F
12/18/2014
Two wire systems transmit and receive on the same pair of wires, which can lead to trouble. The
host must not only disable its transmitter before it can receive data, it must do so quickly, before a
drive begins to answer a query. The SV drives include a “transmit delay” parameter that can be ad-
justed to compensate for a host that is slow to disable its transmitter. This adjustment can be made
over the network using the TD command, or it can be set using the QuickTuner™ software. It is not
necessary to set the transmit delay in a four wire system.
RS-232 to RS-485 2-wire Converter
Model 485-25E from Integrity Instruments (800-450-2001) works well for converting your PC’s RS-
232 port to RS-485. It comes with everything you need. Connect the adaptor’s “B” pin to the
drive’s TX+ and RX+ terminals. Connect “A” to the drive’s TX- and RX- terminals.
Converting USB to RS-485
The USB-COMi-M from www.byterunner.com is an
excellent choice for USB to RS-485 conversion. It can
be used with 2 wire or 4 wire systems.
For two wire RS-485, set SW1 to ON and SW2-4 to
OFF. On the USB-COMi-M screw terminal connec-
tor:
Pin1 goes to RX- and TX-.
Connect pin 2 to RX+ and TX+.
Pin 6 is ground.
The DB-9 is not used.
RS-485 Two Wire System
+RX- +TX- GND +RX- +TX- GND +RX- +TX- GND
to PC TX+ (B)
to PC TX- (A)
to PC GND
Drive #1 Drive #2 Drive #3
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