I'm currently working on a project with the ADE7758. For testing purpose I've connected an adjustable AC-source with a maximum voltage of 18 Volt (RMS) to the IC through my filter network. The filter network is designed for +/- 500 V according to the datasheet.
I configured WAVMODE (0x15) to binary 00000100 [PHSEL: 00 (Phase A) / WAVSEL: 001 (Voltage) / DTRT: 00 (26.04 kSPS) / VACF: 0]. If I'm getting the datasheet right, this configuration should submit reading voltage-waveform data for phase A when reading WFORM (0x12) but unfortunately I only receive zeros in response.
Next thing I've checked is the Interrupt Status Register (0x19) as I read somewhere that reading samples from WFORM is only possible if WFSM-flag is set. What I noticed by continuously reading the Interrupt Status Register is that WFSM-flag won't change its status to "1", so it seems there's no data present from the WFORM-register.
In addition I can read the value from the AVRMS register, detect the zero-crossing of phase A using the Interrupt Status Register and by applying my calculated conversion constant I get a "real world"-voltage that's quite close to my reference meter (even without calibration done so far).
I would really appreciate if someone could give me a hint how to solve this problem...