I'm trying to replace an dot matrix printer that's attached to an Ademco 685 digital alarm receiver.   I've got some communications working but am getting little data on the screen.   Unfortunately there is no manual for this alarm panel so I can't get the exact communications settings I need.   I was wondering if anyone knew of some default parameters that might work.   Currently when I put the panel in alarm i get just an f on the display.    I've got the baud at 1200 and have tried all the parity and stop bit combinations, but still receive an framing error.   Thanks.