AERCO Modulex E8 Controls Guide - Manual (Page 70)

PR1: 11/30/12 Page 70 of 112
GF-115-C Modulex E8 Controller and BCM
Operations and Maintenance Manual
OMM-0084_0D
AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 • Ph: 800-526- 0288
7.6 Modbus Network Wiring Diagram
A “Sample” Modbus Network wiring diagram for an AERCO BMS II/ACS Master controlling BCM
Slaves is shown in Figure 7-10. Activate the terminating resistor in the last BCM on the daisy-
chain loop. DO NOT install the 1K bias resistor. Instead, activate the two bias DIP switches in
the BMS II/ACS. Refer to GF-124, Figure 2-6 for the location of these switches.
Figure 7-11 shows a Sample Modbus Network wiring diagram for a Master EMS/BAS
controlling BCM Controller Slaves. This Figure shows an EMS or BAS Master equipped with a
RS485 port. If the EMS or BAS contains a 4-Wire RS485 port, refer to Detail “A” for wiring
details. If the controlling Master EMS/BAS contains only a RS232 port, a RS232-to-RS485
converter will be required to interface with connector Y2 at each BCM Controller. It should be
noted that this diagram is only intended as a guide and does not include all possible scenarios.
Refer to the EMS/BAS manufacturer’s manual prior to attempting any network wiring
connections.
CAUTION!
It is imperative that polarity be maintained between all Modbus
Network connections. The Network will not operate if the proper
polarity is not maintained. Also, twisted-pair wiring shields should
only be terminated at the controlling Master for the Modbus
Network.