Emerson E2 MultiFlex-Plus + Board, Wiring Types, I/O Network Structure Daisy Chains

Board	Max #	Translation	Boards That
Type			Match Board Type
PAK	32	MultiFlex PAK rack	MultiFlex PAK
		controller
CCB	99	CCB case controllers	CCBs
ESR	31	MultiFlex ESR valve	MultiFlex ESR
		controller
CUB-	32	Single condensing	MultiFlex CUB II
II		unit controller (one
		compressor and up to
		4 condenser fans)

Table 6-1- Board Types and Boards Included in Each Type

6.1.2MultiFlex-Plus (+) Board

The MultiFlex-plus board contains a replacement RS485 transceiver chip that presents less of a load on the network than a non-plus board. This increases the maxi- mum number of devices that can be placed on the network, but not the number of board types an Einstein controller can communicate with.

The MultiFlex-plus board now accounts for only 1/8 the load of a non-plus board with 32 total devices on the network (one Einstein controller + 31 boards). This new conversion allows for the placement of 256 devices on the network (one Einstein controller + 255 boards). The num- ber of boards an Einstein controller can support is increased from 31 up to 255 using MultiFlex-plus boards only. In other words, the number of I/O net devices are no longer restricted by the I/O net 31-node limitation.

NOTE: The MultiFlex-plus board replaces the old-style MultiFlex boards and is currently being shipped.

6.1.2.1Board Designation

Plus boards are always identified with a plus (+) sign that appears on the plastic insulating cover on the top of the board, after the board name.

6.1.2.2Board Calculations

With X as the number of plus boards and Y as the num- ber of non-plus boards, use the following equation to ensure that the number of devices on your network has not exceeded the maximum load limitation of the network. For example, if the total number of devices is less than 256, the maximum load limitation has not been exceeded.

X + (Y • 8) < 256

6.1.3Wiring Types

Retail Solutions specifies all RS485 I/O and MOD- BUS wiring used by the E2 must be Belden 8641 (24AWG, 300V, Retail Solutions P/N 135-8641); Belden 8761 (22 AWG, 300V not stocked by Retail Solutions); or a 600V-shielded 22AWG equivalent stocked by Retail Solutions (P/N 135-0600). These are two-connector shielded twisted pair cables that support a maximum daisy chain cable distance of 4000 feet (1219 m) between the E2 and the end device on the network.

6.1.4The I/O Network Structure (Daisy Chains)

The RS485 Input/Output (I/O) Network connects all input and output communication boards together in a sin- gle open communications loop. This loop, or “daisy chain,” connects the E2 to multiple input and output com- munication boards, and terminates at the last input or out- put board on the network. A diagram of this network arrangement is shown in Figure 6-1.

Figure 6-1- I/O Network Configurations

6.1.5Network Noise Minimiza-

tion

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:

6-2 • E2 RX/BX/CX I&O Manual 026-1610 Rev 13 14-SEP-2011