Instruction manual

ACU-1000 Operations Manual
Interoperability Now 2-101
2.17.3 PSTN-2 Configuration items
2.17.3.1 Telephone Line Level
This configuration item programs the PSTN-2 for different telephone line levels. The
selections for n are 0=0 dBm, 1=-3 dBm, 2=-6 dBm, 3=-9 dBm (default), 4=-12 dBm, 5=-15
dBm, 6=-18 dBm, 7=-21 dBm, 8, 9 both= -24 dBm. This command simultaneously sets the
telephone send and receive levels. The default setting is -9 dBm, which is the maximum level
allowed into U.S. (and most foreign) telephone networks at the subscriber end. Many PABX
units require a level of -12 dBm. Higher levels should only be selected for use into field wire
or private networks that are known to accommodate higher levels. Do not use this command if
the telephone receive audio volume is too low; use the Telephone Receive Level Boost
command instead (next paragraph).
2.17.3.2 Telephone Receive Level Boost
This configuration item provides additional volume to the PSTN module’s receive input. The
Telephone Line Level item explained above sets the correct audio levels for proper hybrid
operation and correct levels on the PSTN line. This configuration item is used to boost the
PSTN receive audio at the output of the hybrid. When necessary, use this command to increase
the volume of audio coming into the PSTN so it matches the volume level of other audio
signals in the ACU-1000 system. The factory default of a 6 dB boost works for most systems,
but if a different level is required, the options for range from 0 to 12 dB.
Refer to Section 2.17.3.15 for a PSTN Simplified Setup Procedure.
2.17.3.3 PSTN Type
This configuration item allows the PSTN module to be programmed for either a normal
telephone system or an Inmarsat M SATCOM terminal. The only difference is the Satcom
terminal requires a "#" be appended to the entered telephone number. When the PSTN-2 is
programmed for Satcom operation, this is done automatically, so the “#” need not be entered
by the user. The factory default is for a regular telephone line; the only other selection is for
SATCOM use.
2.17.3.4 Dial Mode
The PSTN module can use either DTMF (Dual Tone Multi Frequency, otherwise known as
"Touch-Tones") or Pulse Dialing. In most systems, DTMF is used, but some older systems
may still require the use of Pulse Dialing. This configuration item sets the unit for DTMF
Dialing (default setting) or for pulse dialing. When in the Pulse Dialing mode, all digits after
the initial telephone number are sent not as pulses, but as DTMF. This allows the use of an
answering machine, etc., which require DTMF command input after a connection is made on
the pulse dial system. It will be necessary to put the module into the Data Mode. See Section
3.5.1.9.