Emerson E2 - Manual (Page 88)

8-2 • E2 RX/BX/CX I&O Manual 026-1610 Rev 13 14-SEP-2011
8.3.1 Maximum Number of Eche-
lon Devices
A daisy-chained segment may contain no more than 63
total Echelon devices (also called "nodes"). If there are 64
or more Echelon devices at your site, an Echelon-compati-
ble router (P/N 572-4200) will be required. A router
placed on the Echelon Network allows you to add another
63-node daisy-chain network. For larger installations,
multiple routers can be used to extend the network indefi-
nitely.
More information about routers and how they are used
in a daisy-chain Echelon Network can be found in the
Router and Repeater Installation Guide (P/N 026-1605).
8.4 Device Termination
In a daisy-chain configuration, both ends of the net-
work segment must be terminated. Terminate the E2 by
setting jumper JP7 to the UP position, as shown in Figure
8-3. Other devices on the Echelon Network are terminated
either by jumpers on the control board or by connecting a
102-ohm “terminator block” at the end of the network seg-
ment (see Section 8.4.1, Using a Termination Block (P/N
535-2715) to Terminate a Daisy Chain). Refer to the
installation guide references at the end of this section for
specific device termination instructions.
All other E2s and Echelon devices that aren’t at the
end of a daisy-chained network segment must be untermi-
nated.
If a router or repeater is being used in a network, termi-
nation becomes more complicated, because routers and
repeaters join multiple daisy-chain segments together.
Refer to the Router and Repeater Installation Guide (P/N
026-1605), for specific termination instructions.
Figure 8-1 - Echelon Wiring - Subnets
Figure 8-2 - Echelon Wiring, pt. 2
E2 E2
E226513125rev
RECOMMENDED
UNBROKEN
CHAIN
E2s
E226513131rev
Figure 8-3 - E2 Termination - Daisy Chain
JP7
JP7
E2
Termination