Instruction manual

ACU-1000 Operations Manual
Interoperability Now 2-91
• Determine the proper input level to the connected equipment (output level from the
module). It may be necessary to monitor the module’s output audio level at the
connected equipment’s input port with an audio voltmeter or other means.
• Start with the TX output at its lowest level.
• Raise the output level one step at a time until the proper level is reached.
2.17.2.3 COR Polarity (DSP and RDI-1)
This configuration item allows the module’s hardwired COR input to work with either an active
low or an active high COR input. If the radio’s COR output goes low when a signal is being
received, set the input to active low; if the radio’s COR output goes high when a signal is being
received, set the input to active high. This configuration parameter does not need to be
programmed unless the hardwire COR input will be used.
2.17.2.4 Full/Half Duplex (DSP and RDI-1)
This configuration item configures the module for either full duplex or half-duplex operation.
Set to full duplex if the connected radios or equipment can transmit and receive at the same
time. Set to half duplex otherwise.
2.17.2.5 DTMF Mute Timer (DSP and RDI-1)
When a module is not in the Data Mode (See Section 3.5.1.9), all DTMF signals detected in the
receive audio are interpreted as commands meant for the receiving module. When the DTMF
Mute Timer is enabled, the DTMF signals are “Muted”; that is, they are not passed on to the
ACU-1000 internal audio bus to be routed to another module, nor are they sent back out in any
module’s TX audio. A module cannot instantaneously mute a DTMF signal; some time is
required to detect its presence. Therefore, when a DTMF signal first becomes present in the
receive audio, a short burst is passed through. The DTMF mute timer ensures, if a long string
of DTMF characters are present in the receive input, a short burst of only the first DTMF
character is passed through. This is accomplished by muting the audio as soon as the first
character is detected, and then keeping the audio muted until the first character is complete, and
until enough of the next character has been received so it is detected. Each time a new DTMF
character is detected, the timer is reset. When the timer expires (because no new DTMF
character is detected in the receive input), the audio is no longer muted.
The factory default is DTMF Mute Timer Disabled, as the majority of ACU-1000 systems do
not employ DTMF control. This setting allows the DTMF signals to be passed through the
system like all other audio. It also prevents inevitable occasional “falsing” on voice signals that
are similar to a DTMF character; this falsing would momentarily mute throughput audio.
If DTMF control is used, it may be desirable to mute the DTMF characters as they may be
annoying to other system users, and a timer setting 1 second works well in most cases. If the
setting is too low (because some system users transmit DTMF characters slowly), a short burst
of DTMF will be passed through at the start of each DTMF character. The timer should be set
to a value that is longer than the maximum time elapsed between the end of one DTMF
character and the start of the next.