Emerson E2 Manuel D’Utilisation

Previous versions of E2 hardware and firmware before 

version 2.30F01 only supported one I/O network port, 
with an optional expansion card that could be used for 
connection to Copeland ISD compressors or IMC/Prodigy 
S-Bus rooftop unit controllers. Beginning with E2 version 
2.30F01, E2s now have up to three RS485 network ports, 
each of which may be configured as an I/O network, IMC/
Prodigy, ISD, or ECT MODBUS port.

Section 5, Serial Configuration of this manual covers 

how to assign COM ports COM2, COM4, and COM6 to 
different RS485 network types. Section 6 (this section) 
explains the network types, the hardware that may be con-
nected to each type, and how to configure the devices. 

All boards and controllers manufactured by Emerson 

Retail Solutions for communication with E2 via RS485 are 
generally referred to as I/O boards, and the network they 
are connected to is referred to as the I/O network 



(or I/O Net).

A COM port configured as I/O Net may connect with 

up to 127 I/O boards. This network is used by the E2 to 
read data from the input boards and to send commands to 
the analog and digital output boards. Some unit control-
lers, such as CCB case controllers and MultiFlex RCBs, 
also communicate with the E2 via the I/O Network.

There are many input, relay output, analog output, and 

combination I/O boards available from Emerson Retail 
Solutions for use with the E2. However, separate from the 
various MultiFlex unit controller models, E2 only recog-
nizes four different types of I/O boards: 16AI, 8RO, 4AO, 
and 8DO. All E2-compatible I/O boards communicate 
with E2 as if they are one or more of these types of boards.

In this manual and in the E2 interface, when you 

encounter these board names, bear in mind that they are 
terms that represent many types of boards. Table 6-1 
describes all the actual boards or board components for 
each E2 “board type.” 

 

16AI

16

Any I/O board that 
has digital and ana-
log inputs. The 
inputs of a combi-
nation I/O board 
(8IO or MultiFlex 
combo board) are 
by themselves 
treated as one 
16AI.

•16AI (discontinued)

•8IO (discontinued)

•MultiFlex 16

•The inputs on all Mul-

tiFlex combo boards 
(88, 88AO, 168, 
168AO, and 1616)

•All versions of the 

Gateway board (some 
versions behave like as 
multiple 16AIs)

8RO

31

Any I/O board with 
relay outputs. The 
relay outputs of a 
combination I/O 
board (8IO or Mul-
tiFlex combo 
board) are by 
themselves treated 
as one 8RO.

•8RO

•8ROSMT

•The relay outputs on 

all MultiFlex combo 
boards (88, 88AO, 
168, 168AO, and 1616 
(which behaves as two 
8RO boards)

•8IO (discontinued)

4AO

16

Any I/O board with 
analog outputs. 
The analog out-
puts of a combina-
tion I/O board (8IO 
or MultiFlex 
combo board) are 
by themselves 
treated as one 
8RO.

•4AO

•8IO (discontinued)

•The analog outputs on 

the MultiFlex 88AO 
and 168AO

8DO

16

Any I/O board with 
+12VDC digital 
pulse outputs.

•

8DO (including all 
versions of the 
PMAC and PMAC 
II anti-sweat control-
ler)

•Digital outputs on the 

MultiFlex 168DO

ARTC/
RTU

32

Rooftop HVAC 
controller board

MultiFlex RTU and 
ARTC (discontinued)