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S.M.A.R.T. ADA-C
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42004-351H
\\s_eng\gtcproddocs\standard ioms - current release\42004 instr. manuals\42004-351h.doc
02/05
Automatic Line Level Compensation for Optimum Audio Performance
Every telephone line has different audio and electrical characteristics. To accommodate the varying lines,
the telephone has an automatic line level compensation function. When a telephone is first installed and
connected to a telephone line, we recommend initiating the automatic level compensation feature. The
automatic line level compensation is initiated in the programming mode with the *78 command, as
follows:
*780
Data transfer command
#
End-of-string indicator
After the
*78
command is successfully entered, the phone returns a system-generated DTMF check-digit.
To complete the automatic line level compensation, when programming is completed and the phone
placed back on-hook, the following process must be followed:
For single button emergency phones:
1.
Remove the phone from the back box or enclosure.
2.
Disconnect the emergency push button from J7, the “Emerg PB” socket on the phone PCBA.
3.
Connect the emergency push button to J1, the “Call PB” socket on the phone PCBA. Press the
emergency push button. When dial tone is steady (with no volume variations), the process is
complete. Depending on the phone line and the duration dial tone, it may be necessary to repeat this
step one or more times.
4.
Disconnect the emergency push button from J1, the “Call PB” socket on the phone PCBA.
5.
Reconnect the emergency push button to J7, the “Emerg PB” socket on the phone PCBA.
6.
Install the phone in the back box or enclosure.
For emergency phones with a call push button and keypad:
Press the call push button. When dial tone is steady (with no volume variations), the process is complete.
Depending on the phone line and the duration dial tone, it may be necessary to repeat this step one or
more times.
