Johnson Controls Metasys NAE55, Installation Manual, Page: 8 / 20

Note: If the number of M-Bus unit loads or
distances exceeds the specifications of a level
converter, an M-Bus repeater can be wired to
the converter to increase the number of unit
loads and distances. The converter shown in
Figure 13 is capable of handling up to 100 unit
loads. See Ordering information for a list of
M-Bus devices.
3. Connect the 24 VAC supply power wires from the
transformer to the -/~ and +/~ terminals as shown
in Figure 13.
Figure 13: M-Bus Level Converter Connections
Table 6: M-Bus Level Converter connection
detail
Callout Description
1 M-Bus connections:
13: M+
14: M-
2 Power connections (24 VAC/DC):
9: PE
11: 24+ V/~
12: 24- V/~
Table 6: M-Bus Level Converter connection
detail
Callout Description
3 RS-232 wire connection (serial cable INT-DX-
KAB01):
5: TxD (transmit data); PIN 2 on RJ12
6: RxD (receive data); PIN 3 on RJ12
7: GND (ground); PIN 5 on RJ12
4 To network engine RS-232C port
Connecting KNX devices
About this task:
The network engine connects to a KNX network device
by using the KNX/IP interface router. (After installation
and wiring are complete, refer to the
Network Engine
Commissioning for KNX Vendor Integration Application Note
(LIT-12013148)
for additional information.)
1. Connect an Ethernet cable from the building's
network jack to the port on the front of the KNX
gateway (Figure 14).
Note: Depending on the size of your network,
you can use either a KNX Interface or Router
as a gateway. The Interface connects the
network engine to a single KNX line, while the
Router acts as both an Interface and a Line
Coupler over Ethernet to connect the network
engine to the network, not to a single device.
2. Connect an Ethernet cable from the building's
network jack to the RJ-45, 8-pin Ethernet port on
the network engine.
Figure 14: KNX/IP Interface Router
NAE55 Installation Guide 8