I connected an ELK SS36 dual tone indoor sounder to my OIIe today and it doesn't work. If I turn "supervision" on I get an error on the console so I figured it was a wring issue. I tried connecting the wires from the sounder directly to the board (bypassing the wire run through the wall) and I still get the error and it still wont work. I also tried connecting it to the the outdoor sounder input to see if the indoor input was bad and I still get an error. The siren works fine if I connect it to a 9V battery.