Like NotFuzzyWarm said, you just need a USB to I2C

If you can't find original Avalon ACU's, try one of these:
http://www.ebay.com/itm/USB-to-I2C-IIC-TWI-SMBUS-master-Converter-4pin-ADC-Decoder-Program-24xx-EEPROM-/281920556383
https://www.sparkfun.com/products/9903
http://www.ebay.com/itm/USB-to-I2C-IIC-UART-TTL-Master-Adapter-Converter-STC-ISP-Download-Sample-Code-/121849891172


This may be the housing Canaan is using for their AUC connector:
https://www.digikey.com/product-detail/en/molex-llc/0050579404/WM2902-ND/115057