There are three chipsets that Aceex uses in the 56k modem line. Model DM-56V14HSF/5 uses the Motorola SM56 hardware. Model DM-56V14HSF/2 uses the Conexant (or Rockwell) Soft K56 hardware. Model DM-56V14HCF uses the Rockwell HCF 56K hardware. Refer to the notes on those for additional initialization strings.