The optional waveform capture component provides the TRsSim software the ability to download waveforms from the AI-5620 on a real time basis. The waveforms represent various signals measured from the front panel RJ-11 jack. The TRsSim software refers to these signals as channels and they are:

• AC Coupled Line Voltage
• DC Coupled Line Voltage
• DC Coupled Loop Current
• DC Coupled Common Mode Voltage
• Rear Panel Digital Inputs 'A' & 'B'

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1. Capture of the waveforms present during an on-hook Caller ID transmission. The top green trace shows the AC coupled channel containing the FSK modulated data, while the bottom yellow and blue traces show the line voltage and loop current channels respectively.

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2. Capture of ringing signal with a ringing load applied. Cursors are used to measure the positive and negative peaks for both the line voltage and loop current.

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3. Viewing the FFT of a captured DTMF digit. The waveform view highlights in a red background color the time range used for the FFT calculation. Its position is always fixed to the center of the graph, while its width is determined by the number of sample points used to calculate the FFT.

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4. Viewing a real time FFT of a 1 kHz tone. The purple trace represents the peak hold channel, which shows the effect of transient conditions. The two cursors are used to measure the second harmonic level of the 1 kHz tone. In this case, the second harmonic is normally 55 dB lower than the fundamental tone; however a transient event recorded by the peak hold dramatically increased the harmonic level by approximately 25 dB.