Weird behavior with Python Library with ProXR relayboard

I am using the python3.9 interpreter with the pyserial and ncd_industrial_relay api,

I am getting some very strange behavior with relay 2 and relay 10.

Using Linux Raspbian
Initialized with lines:

con = serial.Serial("/dev/ttyUSB0", baudrate = 115200, timeout = 1)

controller = Relay_Controller(con) #<- ncd api

When I turn on relay 2 I hear a click and the light corresponding to two turns on… and the light for relay 10 turns on.

I receive the response:
>>> controller.turn_on_relay_by_index(2)
[True, [170, 1, 85, 0]]

Then if I turn on relay 10 – I hear a click, and the light for relay two turns off.

[True, [170, 1, 85, 0]]

Then if I turn off relay 10 – I hear no click, and the light for 10 does not turn off, but the light for 2 turns back on.

[True, [170, 1, 85, 0]]

If I repeat this say – turn relay 10 on again – the light for 10 turns on, the light for two turns off, and there is no click.

None of the other relays behave in this manner, additionally if I turn relay 10 on while relay 2 is off everything behaves as expected., but when I turn relay 10 off while relay 2 is off, the light corresponding to relay 2 flashes.

Any ideas what is happening?


Can a mod please respond. I believe I may have a defective board.


@TravisE_NCD_Technica @ryan1 any thoughts


We just spoke on the phone. Please let me know what you find with the Base Station software.

Thank you,
Travis Elliott

Hi Travis, it appears it is in fact an issue with the board. The behavior remains unchanged using the Base Station software.

I’ll start the process to repair the board.