Rs485 Communication - SKF Multilog IMx-S Series User Manual

RS485 Communication

Twisted pair shielded cable shall be used.
Important - Connect the shield only at one end to avoid ground loops.
The cable connection should be done according to the following:
Table 3-7: Cable connection.
IMx-S
RS485 A Out
RS485 B Out
If the IMx-S unit is at the end or beginning of the RS485 Bus, activate the built-in
termination resistor by setting DIP21 according to the table below. DIP21 can be
accessed after the front panel has been taken off. It is located below the Dig3 DIP
switch.
Table 3-8:
DIP21 settings
position: 1234
0100
0000
DIP21 settings
position: 123456
011010
001010
Modbus protocol is used for RS485 communication. IMx-S can be configured as master
or slave. However, if IMx-S is configured as master, only one slave device will be
supported. If more than one slave device is needed, contact SKF Condition Monitoring
Center, Luleå.
For more information regarding RS485/Modbus, refer to "Modbus for IMx & MasCon16
User Manual".
SKF Multilog On-Line System IMx-S
User Manual
RS485 Equipment
A
B
 On newer systems there is a hole in the front panel for DIP21 (no
need to remove front panel).
.
DIP21 functionality
Functionality with I/O board version less than
v1.24 (DIP21-switch with 4 positions)
Termination resistor enabled RS 485
Termination resistor disabled RS 485
Functionality with I/O board v1.24 or greater
(DIP21-switch with 6 positions)
Termination resistor enabled
Termination resistor disabled
Figure 3 - 4.
Front Panel with DIP21 Hole (I/O board v1.24 or Greater).
Unit Configuration
RS485 Communication
3 - 5