Emerson E2 User Manual

Site environments will frequently have numerous 

sources of high EMI, or “noise,” that must be accounted 
for when routing RS485 network cable. Although the 
cable is shielded against noise, the installer must follow 
best practices for minimizing network noise.

In general, installers should follow these guidelines 

when installing RS485 networks:

• Avoid running cable next to noise-generating 

devices, such as motor starters, contactors, invert-
ers, fluorescent light ballasts, arc welders, etc. If 
possible, keep cable less than 1 foot away from 
noise-generating devices (ideally, at least 5 feet). 

• Do not run RS485 cable in the same conduit as 

high-voltage wiring, such as 120VAC or 240VAC 
power wiring. Keep RS485 cable a minimum of 3 
inches away from high-voltage wiring (ideally, at 
least 12 inches). If RS485 must cross paths with 
high-voltage wiring, cross them perpendicular — 
running RS485 and high-voltage wire in parallel 
increases the amount of noise induced on the net-
work.

• Ensure you are grounding each input device’s 0V 

power terminal to a separate earth ground, and set-
ting the termination and biasing jumpers as 
instructed in Section 6.1.8, Setting the Terminating 
and Biasing Jumpers.

For more instructions on best practices for minimizing 

noise, refer to publication 026-1903, E2 Controller Wir-
ing Practices, available in the Product Manuals section of 
the Emerson Climate Technologies Web site: 

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Each device on an RS485 segment has either a network 

dip switch or rotary dials that must be used to assign the 
board a unique network ID number.

The network ID number makes a board unique from 

other boards on the network of the same type. This allows 
E2 to find it and communicate with it easily.

Boards of the same type should be numbered in 

sequence, starting with one and continuing with two, 
three, and so forth. For example, if a segment contains 
four 16AI boards and five 8RO boards, you should num-
ber the 16AIs one, two, three, and four; and the 8ROs one, 
two, three, four, and five. The same should be done with 
multiple 4AO and 8DO boards, and IRLDS leak detection 
units.

For all boards, except 8IO and 8DO boards, the net-

work dip switch labeled S1 (or S3 for the 16AI board) is 
used to set the unique board number of the unit and the 
baud rate. The 8IO and 8DO uses rotary dials to set the 
board number of the unit.
Numbering the MultiFlex Combination I/O Boards

When it comes to network numbering, the MultiFlex 

Combination Input/Output boards (88, 88AO, 168, 
168AO, and 168DO) are special cases. They are actually a 

combination of three types of Emerson Retail Solutions 
boards: the inputs are configured like a 16AI, the relay 
outputs are configured like an 8RO, and the analog outputs 
are configured like a 4AO.

When a MultiFlex combo board is present on the net-

work, it must be addressed like all three board types. 
Therefore, when numbering these boards, you must set a 
unique number for both the 16AI, 8RO, and 4AO compo-
nents of the board.
Addressing the MultiFlex Boards

For MultiFlex boards, set positions 1 to 5 on S3 for the 

16AI component and positions 1 to 5 on S4 for the 8RO 
component. Set positions 6 to 8 on S4 for the 4AO or 4DO 
segment. For MultiFlex board controllers, use positions 1 
to 5 on S3 to set the address.
Addressing the MultiFlex ESR Boards

The MultiFlex ESR uses standard Emerson Retail 

Solutions I/O Network addressing. Set positions 1 to 5 on 
S1 to set the network ID (address) of the MultiFlex ESR 
from 1 to 31.

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 
4800, 9600, 19200, and 38400. Setting of the baud rate is 
accomplished using dip switches (refer to the board’s 
installation sheets at the end of this section for specific dip 
switch settings).
Baud Rate for the E2

The baud rate default for E2 is 9600.

The Gateway can be set to either 9600 baud or 19.2K 

baud by dip switch #6. “ON” places the rate at 9600 baud 
while “OFF” sets it at 19.2K baud. 

Dip switches 6 and 7 control the baud rate at which 

the Gateway communicates with the site controller on the 
RS485RS485 Network. These switches must be set to the 
same baud rate setting as the E2 or REFLECS (usually 
9600 baud).