Door Control W-1000/2000A/3000 Viking door entry/ CCTV controller Allows single line phones or phone systems to share a phone line with one or two Viking doorboxes or Provides two Touch Tone controlled relays to operate door strikes or gate openers and provides doorb Switch between two CCTV cameras when either doorbox is activated Handy as a line concentrator - one fax machine or answering machine can answer 3 lines