Honeywell TB7300 Benutzerhandbuch

63-4524—01

8

The polarity of the connection to the cable is important. From one module to the other it is important that the same colored wire be 

connected to “plus” or “+” and the other colored wire be connected to the “minus” or ”-“. Figure 5 shows the proper MS/TP 

connections and the location of the Status LED. This Status LED may help to troubleshoot network problems.

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.

Table 3 shows the different possibilities with the Status LED behavior for a BACnet module.

• 1 short blink

BACnet communication NOT active at 
default MAC address = 254

Change MAC address to another 
value from 0 to 127

• 2 short blink (no wires 

connected to the module)

The right module has been installed on 
the right thermostat model

N/A

• 2 short blink (wires connected 

to the module)

Module is not at the same baud rate as 
the network 

Power off and on the thermostat

• 2 short blinks and a longer blink 

(wires connected to the 

module)

The module has detected the presence 
of a network

N/A

• Right after power is applied: 2 

long blinks and then no blinking

Polarity has been reversed at the 
module

Reverse polarity at the module