Sine to 600 kHz, square, ramp, triangle to 50 kHz 12 bit direct digital synthesis Tone, DTMF, digital, Hop Ram sequence modes One or two outputs One to four internal channels AM, FM, Phi-M, DSBSC, and pulse modulation Unit to unit phase synchronization The Agilent HP 8904A also has five other standard functions: square, triangle, ramp, from 0 Hz to 50 kHz plus DC, and Gaussian white noise. All waveform values in the Keysight Agilent HP 8904A are digitally calculated in real time by Keysight Agilent HP's Digital Waveform Synthesis IC yielding 12-bit digital accuracy. Full GPIB programmability is also included standard on the Keysight Agilent HP 8904A.