Rockwell Automation 999 IMC S Class Compact Motion Controller (Cat. No. 4100-999-122) - Manual (Page 51)

Installation and Hookup 4-9
Publication 999-122 - January 1997
To configure either serial port for RS-422 communications, carefully
move the first (port A) or second (port B) pair of switches to their up
positions using a pen, small screwdriver, etc. For example, the figure
below shows serial port A configured for RS-232 and serial port B
configured for RS-422.
In Multidrop applications, only the first and last IMC-S/23x on the
RS-422 line should be terminated. All intermediate IMC-S/23x
controllers should not have their multidrop serial port terminated. For
example, the figure below shows serial port A configured for RS-232
and serial port B configured for RS-422 without termination.
Port A Port B
RS-
4
2
2
22
0
Ω
RS
-4
2
2
T
e
rm
RS-
4
2
2
22
0
Ω
R
S
-422
T
e
rm
DH-
4
8
5
22
0
Ω
DH-
4
8
5
T
e
rm
RS
-2
3
2
No
RS-
4
2
2
T
e
rm
R
S
-232
No
RS-
4
2
2
T
e
rm
R
S
-232
/42
2
N
o
DH-
4
8
5
T
e
rm
Port A Port B
RS
-4
2
2
22
0
Ω
RS-
4
2
2
T
e
rm
RS-
4
2
2
220
Ω
RS-
4
2
2
T
e
rm
DH-
4
8
5
22
0
Ω
D
H
-48
5
T
e
rm
RS-
2
3
2
No
RS
-4
2
2
T
e
rm
RS-
2
3
2
No
RS-
4
2
2
T
e
rm
RS-
2
3
2
/4
2
2
No
D
H
-4
8
5
T
e
rm