STA-III Plus – Smart Telephone Autocoupler

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STA-III Plus – Smart Telephone Autocoupler


The STA-III Plus provides a convenient interface between a telephone line and the user’s equipment. Features include auto-answer after a user programmed number of rings, user programmed numeric DTMF access code and relay and audio in/out control via numeric DTMF commands.



  • Auto-answer and auto-disconnect via CPC (calling party control) and/or long dial tone hang up signals, allowing use behind analog PBX switches and POTS lines.
  • Front panel, plus remote line seize and drop control for manual operation.
  • Electronic telephone hybrid.
  • Remote controllable send and receive audio.
  • Balanced bridging audio input with front panel level control.
  • Balanced low Z audio output with front panel level control.
  • Front panel LED’s display power, hook, ring and valid DTMF tone.
  • Two remote controllable SPDT relays
  • SPDT End of Call relay.
  • External SPDT hook relay activates when a valid access code is entered.
  • Remote line busy input.
  • User programmable number of rings before auto-answer.
  • User programmable access code, up to 10 digits.
  • Loop-thru phone jack.
  • Plug-in euro-block screw terminals for audio and remote control connections, mating plugs supplied.
  • Fully RFI proofed.
  • Surge protected internal power supply, 12 VDC universal switching power supply with domestic connectors supplied. International AC connectors optional.
  • Each unit may be set on a desktop, mounted on a wall or rack-mounted with the optional RA-1 rack shelf for mounting up to three units in 1-RU.