ProSoft Technology MVI56-103M - Manual (Page 96)

Reference MVI56-103M ♦ ControlLogix Platform
User Manual IEC 60870-5-103 Master Communication Module
Page 96 of 152 ProSoft Technology, Inc.
February 22, 2013
Note: Terminating resistors are generally not required on the RS-485 network, unless you are
experiencing communication problems that can be attributed to signal echoes or reflections. In
these cases, installing a 120-ohm terminating resistor between pins 1 and 8 on the module
connector end of the RS-485 line may improve communication quality.
RS-485 and RS-422 Tip
If communication in the RS-422 or RS-485 mode does not work at first, despite
all attempts, try switching termination polarities. Some manufacturers interpret +
and -, or A and B, polarities differently.
DB9 to RJ45 Adaptor (Cable 14)