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D. Select RS-485 Address and Connect the
RS-485 Bus Cables
9. Select the RS-485 address for the
RMM2-Eunit.
Each RMM2-E connected to a RAYCHEM NGC
control and monitoring system must have a
unique address; if two RMM2-E’s are assigned the
same address, communication faults will result.
To ensure that you assign a unique address to
each RMM2-E unit, do the following:
• Review the RAYCHEM NGC system layout; if a
layout document does not exist, create one. If
it has not already been done, assign an RS-485
address to each RMM2-E (up to 16) connected
to the RAYCHEM NGC system.
• If you are adding one or more RMM2-E units to
an existing RAYCHEM NGC network, confirm
that the RS-485 addresses for existing RMM2-E
units correspond to the system layout. See
for details the programming guide of the
RAYCHEM NGC system.
By checking the RS-485 addresses on an existing
system, you can avoid potential conflicts that
would be confusing and time consuming to
troubleshoot otherwise.
Record the RS-485 address selected for the
Remote Monitoring Module you are currently
installing, and label the exterior of the enclosure
with the address assigned to the RMM2-E.
For reference, here are the 16 possible RS-485
addresses: (0 -15 HEXADECIMAL)
0 1 2 3 4 5 6 7
8 9 A B C D E F
10. Set the RS-485 address for the RMM2-E unit
using the rotary switch provided
Take of the lid and use a flat-blade screwdriver to
rotate the RS-485 address switch to the desired
position. The single character visible on the
switch indicates the RS-485 address assigned.
0
7
6
0
11. Connect the RS-485 bus
Note: Do not make connections to the RS-485
bus while it is connected to an operating
RAYCHEM NGC network. Damage and/or alarms
could result.
The RS-485 bus allows units with unique
addresses to be connected together along a
common bus. To add a new unit to the network,
simply connect the RS-485 bus from the last unit
to the new one, or insert the new unit between
two existing units on the bus. The order in which
units are attached to the RS-485 bus does not
matter. There are just two constraints on the
RS-485 network:
• Each RMM2-E must be assigned a unique
address
• The RS-485 bus must be a continuous string
from the first network device to the last
RMM2-E in the system.
Note: The RS-485 bus operates at 5 V, and
equipment connected to it could be damaged by
exposure to higher voltages. Take precautions to
avoid exposing the RS-485 wiring to discharge of
static electricity or other sources of high voltage
potential; in particular, avoid contact with the
power supply wiring.
