a circuit and method for detecting an edge of the carrier frequency of received data from a remote ir communications device by an infrared communications controller is disclosed . during the receiving of ir signals from a remote ir communications device such as , for example , a tv , vcr or stereo , a frequency window of frequencies above and below a predetermined carrier frequency is opened . if the edge of the carrier frequency of the received data falls within the frequency window , communications are established between the ircc and the remote ir communications device . if the negative edge of the carrier frequency of the received data does not fall in the frequency window of frequencies , then the system aborts communications . provisions are made for a ten percent , a twenty percent frequency window , and a forty percent frequency window . other configurations combining various percentage frequency windows are also disclosed as well as methods for generating the frequency windows .