The Kramer Electronics TP-125EDID is a device for sending VGA computer video, stereo audio and RS-232 control signals over twisted pair cables such as CAT-5. The device also receives and stores EDID (Extended Display Identification Data) information from the connected display. The 15-pin VGA is capable of carrying very high resolutions of analog component RGBHV signals, but its transmission distance is limited. For sending VGA and associated audio and RS-232 signals across a facility, one excellent option is converting the signal for transmission over a CAT-5 cable. This enables the signal to travel distances in the hundreds of feet. The TP-125EDID is a PC / RS-232 / audio stereo line transmitter that receives from a computer source an RGBHV video signal and an unbalanced stereo analog audio signal and transmits them over twisted pair cable to, for instance, a Kramer TP-126 receiver.
The transmitter converts the unbalanced audio signal to a digital audio (S/PDIF) stream before transmitting in order to preserve the quality of the signal. The receiver converts the video signal back to VGA and the audio to unbalanced stereo audio, while also preserving S/PDIF for output. The transmitter features a RS-232 port to receive commands from the connected computer and pass them along to a device that's controllable via RS-232, such as a switcher. With the TP-125EDID, RS-232 control is bi-directional, so commands and data can flow in both directions via the interface. This allows for status requests to be sent to the display system and a response to be received. RS-232 also enables control of a compatible destination display.
When the TP-125EDID is connected to a display device and the EDID CAPTURE button is pressed, the transmitter reads and stores the EDID from the display device. Thereby, the display can be disconnected and later reconnected without rebooting the operating system.