Off-Hook Voltage for ETP Modules

Off-Hook Voltage for ETP Modules

OFF hook voltage should be the following for ETP units:

Technical Requirements
  • Dedicated* P.O.T.S. type phone company line or Analog PBX line—you must know if your phone is on a PBX before you begin programming.
    • If connected to a PBX, your extension must provide:
      • at least 24 Volts at 20 mA off-hook (no current is drawn on-hook)
      • either a disconnect pulse (voltage drop at end of call) or 30-seconds of silence after hang-up (no re-order or howler feature)
  • If connected to a P.O.T.S. line, there must be no special features, such as hook-flash, call-waiting, auto-redial when busy or voicemail. If the telephone company has activated any such features or your phone line is “feature ready", contact them to have these features turned off.


If you need additional assistance, please email us at support@talkaphone.com or call 773-539-1100 and select Technical Support.