How to wire and terminate the 9 pin serial port on the Johnson Controls TAD Advanced Displays

The TADs communicate on a RS485 Serial BACnet port to communicate with other field devices

The TAD Serial port is used to communicate with other field devices.The serial port standard is software programmable and for BACnet MS/TP the RS485 isto be selected. 

9 PIN Serial Plug To operate RS485, pins 3-4 and 7-8 must be connected externally