6
D. Select RS-485 Address and Connect the RS-485 Bus Cables
9. Select the RS-485 address for the RMM2
unit.
Each RMM2 connected to a MoniTrace 200N
control and monitoring unit must have a unique
address; if two RMM2s are assigned the same
address, communication faults will result. To
ensure that you assign a unique address to
each RMM2 unit, do the following:
• Review the MoniTrace 200N 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 (up to
16) connected to the MoniTrace 200N unit.
To record the RS-485 assignments, use the
installation record of the MoniTrace-200N
Control Unit Installation Manual
(Tyco Thermal Controls document H56680).
• If you are adding one or more RMM2 units to
an existing MoniTrace 200N network, confirm
that the RS-485 addresses for existing RMM2
units correspond to the system layout. You
can do so by observing the MoniTrace 200N
display. When the MoniTrace 200N displays
a temperature, it identifies the RTD with a
two-part tag; the prefix indicates the RMM2
address, and the suffix indicates the terminal
number to which the RTD is connected. For
example, RTD 3-7 identifies an RTD con-
nected to the RMM2 with address 3, RTD
terminal 7.
By checking the RS-485 addresses on an exist-
ing system, you can avoid potential conflicts
that would be confusing and time consuming to
troubleshoot otherwise.
Record the RS-485 address selected for the
MoniTrace Remote Monitoring Module you are
currently installing, and label the exterior of
the enclosure with the address assigned to the
RMM2. 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
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
0
7
6
0
assigned.
11. Connect the RS-485 bus
Note:
Do not make connections to the RS-
485 bus while it is connected to an operating
MoniTrace 200N control and monitoring unit.
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 con-
straints on the RS-485 network:
• Each RMM2 must be assigned a unique
address
• The RS-485 bus must be a continuous string
from the MoniTrace 200N to the last RMM2 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 precau-
tions 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.