Receiving TTL Signals from 2 Response Boxes (case 13508)

[lisagerm]

I am running an experiment through DirectRT to gather response time data from participants' true/false responses. When an item is presented, I have participants respond using a true/false scale on one response box (they can only select key 2 or 8). After the participant has selected his/her answer, I would like to have the participant press one key (key "5") on another response box to advance to the next item. I have specified in my Excel document that for each item that requires a true/false response, only responses of "2" or "8" from port 7718 should be accepted (syntax: "rt:2,8,(7718)"). I also specify when only key 4 can be pressed on the other response box ("rt:5,(7725)"). When I run the experiment in DirectRT, however, the program registers key presses from either response box. E.g., When a response is restricted to the 5 key, I can only press 5 to advance, but I can do so on either response box. I am unsure what I am doing wrong or if DirectRT is incapable of distinguishing signals from 2 identical response boxes.