Johnson Controls NIE39 Installation Instructions Manual page 8

7. Connect the 24 VAC supply power wires from the transformer to the removable power terminal block plug on
the NIE (Figure 9).
Note: Power supply wire colors may be different on transformers not manufactured by Johnson Controls. Follow
the transformer manufacturer's instructions and the project installation drawings.
8. Connect the 24 VAC supply power wires from the transformer to the converter. No additional external power
adapter is required. Connect the hot and common wires as desired. The NIE does not require an earth ground
connection.
Note: The 24 VAC power should be connected to all network devices so transformer phasing is uniform across
the devices. Powering network devices with uniform 24 VAC supply power phasing reduces noise,
interference, and ground loop problems.
Wiring the NIE for M-Bus Protocol
1. Connect the Ethernet cable to the RJ-45, 8-pin Ethernet port shown in
2. Connect from the RS232C A or RS232C B serial port on the NIE to the RS-232 connecter of the level converter.
Wire to terminals GND, RxD, and TxD as shown in
3. Wire from the M- and M+ terminals on the level converter
line) topology. Specific cabling can vary depending on the topology and site. See
for Network Integrations.
NIE39/NIE49 Installation Instructions
Figure 8: Modbus Wiring Detail Overview
Figure 9: 24 VAC Supply Power Wiring
Figure
Figure 1.
10.
(Figure 10) to the meters using a free (star, tree, or
Wiring Rules and Guidelines
8