Connecting to a host using rs-485 – Applied Motion BLuDC4-Q User Manual
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BLuDC-S,-Q Hardware manual
BLuDC-S,-Q Hardware manual
BLuDC-S,-Q Hardware manual
BLuDC-S,-Q Hardware manual
BLuDC-S,-Q Hardware manual
Connecting to a host using RS-485
RS-485 allows you to connect more than one drive to a single host PC, PLC or
other computer. It also allows the communication cable to be long (more than 1000
feet). But the device to which you connect must have an RS-485 port.
Pin diagram and wiring are shown below. We recommend the use of Category 5 cable. It is widely
used for computer networks, it is inexpensive, easy to get and certified for quality and data integrity.
The BLu Servo Drives can be used with two wire or four wire RS-485 implementations. The
connection can be point to point (i.e. one drive and one host) or a multi-drop network (one host
and up to 32 drives).
Four Wire Systems
Four Wire Systems
Four Wire Systems
Four Wire Systems
Four Wire Systems utilize separate transmit and receive wires. One pair of wires must connect
the host computer's transmit signals to each drive's RX+ and RX- terminals. Another pair connects
the TX+ and TX- drive terminals to the host computer'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-485
network are powered from the same supply it is not necessary to connect the logic grounds. You
should still connect one drive's GND terminal to the host computer ground.
Four wire systems are better than two wire types because the host can send and receive data at the
same time, increasing system throughput. Furthermore, the host never needs to disable its
transmitter, which simplifies your software.
Getting and Connecting a RS485 4-wire adaptor to your PC
(800-831-4242) works well. This adaptor is for a 25 pin
serial port. If you are like most people and have a 9 pin serial port on your PC, you will also need
to purchase Jameco cable 31721. Connect as follows:
adaptor drive
1
RX+
2
RX-
3
TX-
4
TX+
RX+
RX
–
TX
–
TX+
GND
RS-485/422