The EyeSDN USB-A2 is a call recording device for two analogue phone lines or two audio signals. The lines are passively tapped with a high impedance circuit. The device performs DC voltage measurements to detect line states like on-hook, off-hook orringing.
The audio data and voltage information is transferred to the PC via a USB cable, which is also used to power the device. Software on the PC uses the line voltage information and audio samples to detect active calls. The device can obtain caller ID information using DTMF or V.23 modem data and decodes DTMF or pulse dialing. The presence of a call can be detected by either analysing line voltage variations or by identifying speech activity.
The EyeSDN USB-A2 has two groups of multi-colour status LEDs which indicate:
The small form factor and rugged enclosure make EyeSDN USB-A2 suitable for stationary and mobile use.