Emerson RLDS, Installation And Operation Manual

Page: 26 / 82

18 • RLDS I&O Manual 026-1309 Rev 8
4.2.3. Connecting to an E2, Einstein,
or REFLECS Site Controller
Up to three RLDS units may be connected to a site
controller via the Gateway Board. The node address
switch on each RLDS must be set in succession from
1 to 3 in order for the Gateway Board to recognize the
units on the network.
Termination
The three RLDS units and the Gateway Board are
connected serially via MODBUS. If an RLDS is at the
end of the network segment, terminate the unit by

setting the termination switch to the DOWN position.
Otherwise, set the termination switch to the UP

position to leave the unit unterminated.
If the Gateway Board is at the end of a network,
the Gateway Board’s “Receiver Bus” termination
jumpers must be set to the “termination” position
(Figure 4-12) . Otherwise, the jumpers should be set
to the “no termination” position.
Network Wiring
For network wiring, use Belden #8762 or #8641 cable
or equivalent. The total length of network cable in this
configuration may not exceed 4921 feet

(1499 meters).
4.2.4. Connecting the Gateway
Board to the E2, Einstein, or
REFLECS Network
Each E2, Einstein, or REFLECS site controller that
will communicate with one or more RLDS must have
a Gateway Board installed on its RS485 I/O

Network. For E2 and Einstein controllers, this means
the Gateway will be installed on the RS485 I/O

Network; for RMCC, BEC, BCU, and other

REFLECS products, the Gateway will be installed on
the COM A or COM D network.
4.2.4.1. Wire Connection
Using shielded three-conductor network cable
(Belden #8641 or equivalent), connect the RS485 I/O
Network wire to the three-terminal connector on the
Gateway board as shown in Figure 4-13 . For further
information about how RS485 networks are

configured, refer to your site controller’s user manual.
Figure 4-11 - RLDS Units Connected to Gateway, Site Controller
GATEWAY BOARD
RLDS LEAK DETECTORS
MODBUS NETWORK
E2, EINSTEIN, OR REFLECS
SITE CONTROLLER
RS485 I/O NETWORK
TERMINATE
RECEIVER BUS
JUMPERS
TERMINATE
"DOWN"
UNTERMINATE
"UP"
CONTROLLER
Figure 4-12 - Gateway Board Termination Jumpers