Emerson MultiFlex RTU, Installation And Operation Manual

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Wiring Types The I/O Network • 9
3.1.2.1. Numbering the MultiFlex RTU
The MultiFlex RTU is a unique board type on
the RS485 Network by the Emerson controllers.
Each RTU that will be associated with an
Einstein must have a unique number from 1 to
31, which is configured by setting the first five
switches on dip switch bank S3.
Numbering RTUs On The Same Network as ARTCs
Both the Einstein BX and the BCU treat ARTCs
and RTUs as “ARTCs” for purposes of
networking. An RTU and an ARTC should not
be assigned the same number. In other words, if
a network has two ARTCs and two RTUs, do not
number the ARTCs #1 and #2 and the RTUs #1
and #2.
3.1.3. Setting the Baud Rate
All I/O boards have dip switches that determine
the baud rate at which they communicate.
Currently, the baud rate dip switch in network
components may be set at either 9600 or 19200
baud. Either may be used — refer to your site
controller’s user manual for the baud rate
recommendation (currently 9600 baud for both
REFLECS and Einstein controllers).
On all MultiFlex boards, switches 6 and 7 on S3
are used to set the baud rate. To communicate at
9600 baud, set switch #6 UP and #7 DOWN. For
19200 baud, set switch #6 DOWN and #7 UP.
Refer to Figure 3-2 for a visual look at how the
switches must be set.
3.1.4. Setting the Terminating
Resistance Jumpers
All MultiFlex boards and other RS485 devices
have a set of terminating resistance jumpers (one
jumper for each wire lead). These jumpers are
labeled JP2, JP3, and JP4 on the MultiFlex
board.
The purpose of the jumpers is to indicate the two
ends, or termination points, of the segment. On a
daisy chain, one device at the beginning and one
device on the end must be terminated by placing
all three termination jumpers in the OUT
(toward the left edge of the board) position. All
other devices on the daisy chain must be set to
the IN (toward the center of the board) position.
Figure 3-3 shows the proper terminating
resistance jumper settings for the Einstein and
for all I/O boards.
Figure 3-2 - RTU Baud Rate Switches
Figure 3-3 - I/O Network Termination Jumper Settings
S4 S3 S2 S1
23
45
6
78
1
ON
23
45
6
78
1
ON
23
45
6
78
1
ON
23
45
6
78
1
ON
TERMINATION JUMPERS
NO TERMINATION - IN (toward center)
TERMINATION - OUT (toward left edge)