Specifications

3.2.4 Audio I/O Connections
The DAI-2 has one audio input and one audio output. The audio input feeds audio to the telephone line and the audio
output provides audio from the telephone line. The DAI-2 control circuits allow only one audio port to be active at a
time--the DAI-2 is not a telephone hybrid device. Both the input and output are balanced, high level audio ports.
The audio input and output connections are made through screw terminals on the relay panel. The terminals are
located on a small block to the left of J1 (the relay panel connector) and below the power and logic I/O connections.
Figure 3.3; Relay Panel connects at J1
The DAI-2 audio output can drive a balanced high impedance or 600 ohm load at up to about +4dBm. If the DAI-2
audio output is used to drive an unbalanced load, use either output lead and ground. Do not connect either side of
the DAI-2 audio output to ground for an extended period of time or damage to the DAI-2 could result.
The audio output level of the DAI-2 is adjustable through programming. This is covered in the programming section of
this manual. The DAI-2 is factory programmed to a program level of about +2 to +4 dBm with a slight amount of peak
clipping. Higher output level settings will result in higher output level and more clipping while lower settings will result
in lower output levels and little or no clipping.
The DAI-2 has an internal automatic level control (ALC) that attempts to keep both input and output levels consistent.
The behavior of the ALC is programmable. The ALC can also be enabled or disabled on a key-by-key basis.
The DAI-2 audio input is high impedance (>100K), actively balanced input. It can be driven by either a balanced or
unbalanced source. For unbalanced audio sources, connect the source leads to the IN+ and IN- terminals. It does
not matter which lead is connected to which input. Unlike the audio output, there are no restrictions on grounding the
audio input connections. The DAI-2 is designed to automatically adjust for input levels within the range of -10 dBv to
+4 dBv.
3.2.5 Logic-Level Input Connections
The DAI-2 has four programmable logic-level inputs. All logic-level inputs can be driven by a +5 VDC logic signal, a
contact closure, or a ground referenced open-collector. Logic is active low and internal pull-up resistors are present.
In other words, when using an open-collector or contact closure, a pull down to ground activates the appropriate
function. Logic-level inputs 1 through 4 may be held at ground indefinitely but logic-level input 5 (the manual off-hook
control) should not be held down more than 2.5 seconds.
External logic gates should have the same ground reference as the DAI-2. Unused logic-level inputs should be left
unconnected. The time required for a logic-level input change to activate a function is controlled by user-
programming and is discussed in the programming section of this manual.
The logic-level inputs are labeled LL1-LL4 on the relay panel.
DAI-2 Installation page 3. 3