Johnson Controls NAE55 Series, Руководство по установке

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4. To add additional vendor devices, wire from one device to the next in a daisy chain
configuration. The completed wiring should look similar to Figure 11.
Figure 11: Modbus RTU wiring detail overview
Connecting M-Bus devices
To connect a M-Bus device to the network engine, complete the following steps:
1. Connect from the RS232C B serial port on the network engine to the RS-232 connector of the
level converter. Wire to terminals GND , RxD , and TxD as shown in Figure 12.
2. Wire from the M- and M+ terminals on the level converter (Figure 12) to the meters using a
free (star, tree, or line) topology. Specific cabling can vary depending on the topology and site.
See Wiring considerations and guidelines for network integrations .
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 12 is capable of handling up to 6 units
loads, while other models can handle up to 100. 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 12.
13 NAE55/NIE55 Installation Guide