EZB V4:

Devantech 8 Channel 16A USB Relay Module:

Maybe I'm missing something but the product uses an USB port.

How do you plan to connect to EZB V4 without USB ?

Maybe you mean "how do you connect ARC to the Daventech 8 channel 16a USB relay board"?

If so, that's easy... Based on the documentation manual, you merely have to send a command to turn on or off the relay. Here's the manual: http://www.robot-electronics.co.uk/htm/usb_rly16tech.htm

Create a function in your script like this...

function setRelay(relayNumber, trueOrFalse) {

  COM.open("COM1", 19200);  
  
  if (trueOrFalse)
    COM.write("COM1", 100 + relayNumber);
  else
    COM.close("COM1", 110 + relayNumber );
    
  COM.close("COM1");
}

// Turn relay 1 on
setRelay(1, true);

// pause for 5 seconds
sleep(5000);

// Turn relay 1 off
setRelay(1, false);