DAFI (Digital Audio Filtering Initiative)

Overview

This is a FE system for supplying real-time, filtered, audio streams of interferometer/PEM channels to the control room.

1. Real-time Borkspace system
2. Like the OAF system, takes many (all?) of the real-time channels on the RFM (e.g. PEM, LSC, ASC, SUS, SEI) as input.
3. Has matrix to route N input channels into M possible outputs.
4. Each of the M output paths has several hardcoded filtering possibilities as well as several configurable filter modules.
5. Has 8 analog outputs (via General Standards DAC) routed to the control room workstations as well as PEM excitations (speakers).
6. FE CPU resides in MSR (LHO or LLO) or 1Ynot at the 40m.

DSP-type Powers

1. Frequency Shifting (i.e. heterodyned output)
2. Frequency Warping (i.e. upsample / downsample knob)
3. AGC
4. Quasi-Arbitrary Math (e.g. TRX * sin(k * EX_SEISX, or AS_DC * ISS_AC)
5. Lock-loss triggers quench to protect ear-drums

Diagram