2800 Laura Lane • Middleton, WI 53562 | 800.288.9383 • fax: 608.836.9044 | www.tcsbasys.com
8
99
2800 Laura Lane • Middleton, WI 53562 | 800.288.9383 • fax: 608.836.9044 | www.tcsbasys.com
8
9
Installation
No Communication with RS-485 Ports (COM 1 and 2), Ubiquity Time-out, or No Data
Verify each port on the QD2040c has the proper biasing resistors as specified by TCSbus and Modbus standards. Verify
each port is also optically isolated, which cleans up the signal and protects the unit from taking stray voltage off the RS-
485 lines.
A set of LEDs on each of the RS-485 ports on the QD2040c allow the building occupant to view operational status of the
serial communication integrated board:
• GREEN – blinking indicates transmitting (Tx)
• YELLOW – blinking indicates receiving (Rx)
If neither of these lights are functioning, there could be a bad connection, a bad cable, a bad ground, or a bad component.
Contact TCS Technical Support (800-288-9383, ext. 2)
for assistance
.
