Chapter 4 – Special Features
47
Step 3
Now that you have verified that the daisy chain is set up properly, you can use the
various Pocket Motion Planner and Motion Planner tools to configure and monitor
all units on the daisy chain.
RS-485 Communications
Pin Out for 4-Wire RS-485 Communications:
Pin Description
1
Rx+
(also called RD B)
4
Tx+
(also called TD B)
5
GND
(logic ground)
7
Rx-
(also called RD A)
8
Tx-
(also called TD A)
•
Maximum RS-485 cable length is 4000 feet (1220 meters).
•
To establish unique addresses for multi-drop units, use the ADDR command.
•
Keep wires as short as possible. Termination resistors may be required on long
cable runs.
•
Connect RS-485 cables before applying power to the drive.
(Reconnecting the cables with power applied may cause the drive to interpret
intermittent connections as RS-232 hardware handshake signals; this may result in
shutdown of the RS-485 interface. If this happens, reset the drive to re-enable the
RS-485 interface.)
•
Recommended cable: Belden 9842.
•
Refer to the diagram below for connection information.
R S - 2 3 2 / 4 8 5
c o n n e c t o r
L o n g c a b l e r u n s m a y
r e q u i r e t e r m i n a t i o n r e s i s t o r s
M a s t e r U n i t
T x +
T x -
R x +
R x -
1 2 0
Ω
1 2 0
Ω
S h i e l d
U n i t # 1
U n i t # 2
U n i t # 3
U n i t # 3 1
+ 5 V D C
G r o u n d
P i n 1 ( R x + )
P i n 7 ( R x - )
P i n 4 ( T x + )
P i n 8 ( T x - )
P i n 5 ( G N D )
P i n 1 ( R x + )
P i n 7 ( R x - )
P i n 4 ( T x + )
P i n 8 ( T x - )
P i n 5 ( G N D )
P i n 1 ( R x + )
P i n 7 ( R x - )
P i n 4 ( T x + )
P i n 8 ( T x - )
P i n 5 ( G N D )
P i n 1 ( R x + )
P i n 7 ( R x - )
P i n 4 ( T x + )
P i n 8 ( T x - )
P i n 5 ( G N D )
RS-485 Multi-drop Connections
RS-485 Multi-Drop
Up to 99 Gemini drives may be multi-dropped. (See the previous drawing.)
The ADDR command allows you to establish up to 99 unique addresses. To use
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