Wiring Overview
Power supply, network, and communication connections
See Figure 1 for the location of the power supply terminal, network communication terminals,
Ethernet jack, and modem jack.
Depending on the model, the network engine can connect to an MS/TP field bus trunk, an N2 Bus
trunk, or a LonWorks network trunk. Also, all network engines support two vendor integrations,
such as two Modbus, two M-Bus, or one of each. Or, if a KNX integration is required, three KNX IP
Gateways are supported for one network engine. See Table 13 for a list of all supported dual trunk
applications. The rules, guidelines, and wiring considerations for each type of network or field bus
application are provided in tables of this document.
Power supply
Important:
Install the data protection battery before applying 24 VAC power to the network
engine. See the
Installing the data protection battery
In North America, use a Class 2, 24 VAC power supply with a 50 VA minimum output. Outside North
America, use a 24 VAC SELV transformer at the appropriate rating. The minimum input voltage for
the network engine to operate properly is 20 VAC. See the
Use a dedicated power supply to the network engine only. Do not connect any other loads to the
power supply. Additional loads may cause noise interference.
Ethernet port
The Ethernet port, labeled
ETHERNET
, is an 8-pin RJ-45 network port for connecting the network
engine to Ethernet IP networks. Network engine can connect to Ethernet networks at 10 Mbps, 100
Mbps, or 1 Gbps. This Ethernet port provides IP communications over the building network and to
any third-party integration that uses Ethernet communication, including Modbus TCP, M-Bus TCP,
or KNX.
FC Bus terminal block
The two Field Controller (FC) Bus connections on a network engine are 4-pin removable, keyed
terminal blocks labeled
FC-A
and
FC-B
.
The FC bus connections are optically isolated RS-485 ports with keyed 4-position terminal blocks
that communicate at 9.6k, 19.2k, 38.4k, or 76.8k baud. Use an FC Bus port to integrate an N2
network, BACnet MS/TP FC Bus trunk, or third-party network into the
Metasys
system.
Note:
N2, BACnet MS/TP, Modbus RTU, and M-Bus have different protocols and network
requirements. Do not intermix N2, MS/TP, Modbus, or M-Bus devices on the same FC Bus port.
The SHD connections on the FC terminal blocks are not connected to any earth ground connection.
The FC A and FC B terminal blocks are not interchangeable.
LonWorks network terminal block
The LonWorks TP/FT-10 network connection, available only on the network engine LonWorks
model, is a 3-wire removable, keyed terminal block. The Shield connection on the LonWorks
network terminal block is an isolated terminal and is not connected in the network engine. Use the
LonWorks terminal block to connect LonWorks networks to the network engine.
Computer serial ports
The network engine has two RS-232-C serial ports labeled
RS232C A
and
RS232C B
(Figure 1). These
serial ports are for direct connection using a standard 9-pin female data terminal equipment (DTE)
to 9-pin female DTE null modem cable. The NAE55 serial ports do not support external modems.
7
NAE55/NIE55 Installation Guide
