Network Adapter - Honeywell TB7600 Integration Manual

BACNET INTEGRATION MANUAL FOR TB7600 SERIES THERMOSTATS
End Of Line (EOL) Resistors
MS/TP network must be properly terminated. For daisy chain configurations, you must install an EOL resistor at each end of the
daisy chain. Depending on your MS/TP network configuration, the resistance value of the EOL resistor may change:
• TB7600, TB7300, and/or TB7200 thermostats are installed at both ends of the MS/TP network:
120 Ohms resistor should be installed at each end.
• A TB7600, TB7300, or TB7200 device is installed at one end of the MS/TP network and another device is installed at
the other end:
Install an End-Of-Line resistor value that matches the other device's instructions regarding its EOL resistor value;
• Other devices are installed at both ends of the MS/TP network:
Follow the other device's instructions regarding its EOL resistor value.

NETWORK ADAPTER

The polarity of the connection to the cable is important. From one module to the other it is important that the same color wire be
connected to "plus" or "+" and the other color wire be connected to the "minus" or "-". Fig. 5 shows the proper MS/TP connections
and the location of the Status LED. This Status LED may help to troubleshoot network problems.
Fig. 5. Correct MS/TP connections and location of a Status LED on a BACnet module
IMPORTANT NOTE: The Ref terminal should NEVER be used to wire shields. The 2 shields from each feed of the network
connection to a thermostat should be wired together in the back of the thermostat and properly protected to prevent any
accidental connection to the ground.
The joined shield connection should then be grounded at a SINGLE point on the whole segment. More than one ground
connection to a shielded wire may induce ground loop noises and affect communication.
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