Instruction manual

ACU-1000 Operations Manual
Interoperability Now 3-13
3.6.1.5 Remote DTMF – Data / Command Modes
When an ACU-1000 interface module detects DTMF in its receive audio, it can either interpret
the DTMF tone as a command input (Command Mode) or transmit DTMF via a connected
PSTN-2 module so this DTMF can control other equipment (Data Mode). When in the Data
mode, the DTMF input is detected and interpreted. This information is passed to the connected
PSTN-2 module, which then regenerates the DTMF and inserts it into the PSTN-2 audio
output. This regenerated DTMF is free of any FM noise or the frequency response related
distortion that often results from the pre-emphasis and de-emphasis of FM audio circuits. The
* 8 0 command toggles a module in and out of the Data Mode. All modules begin operation in
the default Command Mode. When the Data/Command operational command is received, the
module switches to the Data mode and returns the prompt “Data Mode”. Whenever the * 8 0
command is again received, the module responds with the “Command Mode” prompt and
reverts to normal operation.
A simple example of the use of this command assumes the radio user wants to call home and
check the messages on his answering machine. The user makes a connection from the DSP-2
module associated with his radio to the PSTN module at extension 01. Following the voice
prompts provided, he then enters the telephone number at his home. After the call is
successfully made, the user then enters the * 8 0 command. Once he does so, he may enter the
password to gain access to his home answering machine. All subsequent DTMF entries will
result in the regeneration of the DTMF characters until he either toggles back out of the Data
Mode with another * 8 0 entry or disconnects with a * # entry. The module that’s receiving the
DTMF should also have its DTMF Mute timer enabled (see the DTMF Mute Timer
explanations in Section 2.16).
It is important to note only the PSTN-2 module regenerates DTMF in this way. The Data
Mode was created mainly to allow an ACU-1000 user to gain access to the system through any
type of module, make a connection to a PSTN-2 module and be able to control equipment that
commonly uses DTMF signaling (voice mail systems, answering machines, etc). It is possible
to use the Data Mode (with the DTMF Mute Timer disabled) to cause input DTMF to be
repeated through the ACU-1000. This is not advisable because of the FM noise that will be
mixed with the DTMF, along with the frequency response related distortion that will be
compounded by the fact that the DTMF will be repeated through two radios.
3.6.1.6 Remote DTMF – System Reset Feature
The System Reset Feature allows a user who is interfaced with the system via a DSP-2, RDI-1,
or PSTN-2 module to reset the ACU-1000 to its initial power-up state. This means all current
connections will be lost, and the unit will return to any connections stored by the * 3 6
command (See Table 3-1 and Section 3.5.1.10). In order to prevent any inadvertent or
unauthorized use of this powerful feature, the System Reset Feature can only be used after first
being enabled at the HSP-2A keypad. In addition, a “system reset code” is entered via the
HSP-2A, and remote users accessing the system via DTMF users must enter this code in order
to implement the System Reset feature.