Table 20: Maximum number of devices per LonWorks network segment
Device Type Maximum Allowed
Free Topology One free topology terminator required (NU-EOL203-0)
Notes:
• Each LPT10/11 channel segment (between repeaters) requires its own power supply. Other factors, such as power
consumption of individual LPT10/11 devices, may limit a segment to fewer devices.
• The MS-NAE552x-x models that support LonWorks Network trunks do not have an internal network terminator.
Table 21: NAE55 with integrations trunk options
Trunk Type Supported Trunk Application
Modbus • 2 RS485 or
• 2 RS232 or
• 2 TCP or
• 1 RS232 + 1 RS485 or
• 1 RS232 + 1 TCP or
• 1 RS485 + 1 TCP
M-Bus • 2 RS485 or
• 2 RS232 or
• 2 TCP or
• 1 RS232 + 1 RS485 or
• 1 RS232 + 1 TCP or
• 1 RS485 + 1 TCP
Modbus and M-Bus • 1 RS485 Modbus + 1 RS485 M-Bus or
• 1 RS232 Modbus + 1 RS232 M-Bus or
• 1 TCP Modbus + 1 TCP M-Bus or
• 1 RS232 Modbus + 1 RS485 M-Bus or
• 1 RS485 Modbus + 1 RS232 M-Bus or
• 1 TCP Modbus + 1 RS232 M-Bus or
• 1 TCP Modbus + 1 RS485 M-Bus or
• 1 RS232 Modbus + 1 TCP M-Bus or
• 1 RS485 Modbus + 1 TCP M-Bus
KNX • 1 KNX (routing mode) or
• 3 KNX (tunneling mode)
Repair information
If you replace a network engine for any reason or add a
new network engine to a site, you must update the site
registration to ensure that the new network engine is
recognized and able to communicate on the Metasys
system site. For details refer to the Replacing an NAE
section in the NAE Commissioning Guide (LIT-1201519).
Except for replacing the data protection battery, the
network engine cannot be repaired in the field. If the
network engine fails to operate, it must be replaced.
Batteries removed from this device must be recycled
or disposed of in accordance with local, national, and
regional regulations. Only trained technicians or qualified
building maintenance personnel should service Johnson
Controls products.
Ordering information
The following table lists the product code numbers for all
available NAE55 network engines based on model. If you
receive an NAE55 engine from the factory that is imaged
with Release 10.1, you can field-upgrade the engine to
Release 11.0 if the upgrade is supported.
Note: Some network engines are also available in
a Buy American version (add a G after the product
code number). For repair parts, specify 703 in place
of the last digit of the product code number.
NAE55 Installation Guide16