Systems and methods for smoke detection are provided. Aspects include operating a first device to transmit a first alphanumeric code to a second device by transmitting a modulated optical signal to the second device, wherein the modulated optical signal represents the first alphanumeric code, wherein the first device comprises an optical signal source configured to transmit a modulated optical signal through a medium, and wherein the second device is configured to receive the modulated optical signal through the medium. Analyzing the modulated optical signal received at the second device to convert the modulated optical signal to a second alphanumeric code and comparing the first alphanumeric code to the second alphanumeric code to determine a presence of one or more conditions between the first device and second device.