sainsmartUSB Eight Channel Relay Board for Automation - 12 V

The unit is functioning as expected. However, after it's use more, the unit cause computer to crash, when turning the on/Off a few time, the program hang up on the write command. The computer needed to reboot to recover. Any idea about this issue ? There are posts on the web that shows the similar issues. Do you have …

Do they provide a tool to control the board through command line?

Can this be used to give nc / no contacts?

I want use as programmable sequential controller for my business led street sign, this unit need computer for program only or need computer to run.