CONNECTING BACNET
33
BACnet Cable Connections
The network uses shielded twisted pair wire. The BACnet wiring terminal connector on the
iCOMM™ system’s CM (communication module) is a 5 pin cage-clamp type plug. One
twisted pair is used for the D+ and D- signals and connected to their respective terminals. A
third wire (if supplied) is used for the Reference (or common wire) and is connected to the R
terminal.
When two BACnet cables are present the cable shields should be joined together and
connect to the S terminal. It is best to twist together the shared wires and cable shields from
the two cables before insertion and tightening of the screw terminal. Shield is not connected
internally but provided as a connection convenience.
Connecting BACnet cable(s):
1 Turn off power to the CM; unplug the 5 VDC round power supply plug from the 5 VDC socket on
the CM - see Figure 22.
2 Unplug the BACnet wiring terminal connector from the CM (communication module) to make
connections.
3 Make cable connections to the wiring terminal as described above and shown in Figure 22.
4 Plug the BACnet wiring terminal connector back into the CM when connections are complete.
5 Restore power to the CM: plug the 5 VDC power supply plug into the 5 VDC socket on the CM.
Figure 22
BACnet Wiring Terminal
Front Edge
CM (communication module)
S
D+
D-
R
N/A
(unplug from the CM to make connections)
1 N/A Not Used
2 R Reference
3 D- Data -
4 D+ Data+
5 S Shield
Display
Button
To Next / From Previous
BACnet device
5 VDC
Socket
