Specifications

3.2.6 Manual Connect Input
There is one single-purpose logic-level input that is used to force the DAI-2 to go off hook. Like the other logic-level
inputs, this one can also be driven by a +5 VDC logic signal, a contact closure, or a ground referenced open-
collector. Logic is active low and an internal pull-up resistors is present. The manual connect input is labeled MAN on
the relay panel.
3.2.7 Control Relay I/O Connections
The DAI-2 has eight control relays built in to the relay panel. Seven of these relays are DPDT and one is 4PDT--
typically used to switch stereo audio. All contacts, normally-open (NO), normally-closed (NC) and common (COM)
are brought out to screw terminals. The seperate relay poles are denoted A and B (with C and D added where
appropriate).
Figure 3.4; DAI-2 Control relay I/O connections
The relay “control” wiring is pre-wired to the DAI-2 control unit via the flat cable, however, the system is fully
programmable and any combination of relays can be engaged through system programming.
The control relay contacts are rated to withstand 110 VDC at 0.6 A but we do not recommend routing high voltage
through the DAI-2. At 12 VDC the relays can withstand 2.5 A but high current should also be avoided as a matter of
safety with so many exposed terminals. The DAI-2 is designed to switch audio, not power.
Sample wiring diagrams are shown later in this section.
3.2.8 Power Supply
One or both of the DAI-2 GND terminals must be connectiond to the station ground or other qood quality
earth-ground. The DAI-2 contains an internal protection circuit that diverts an abnormally high voltage on
the telephone line to the DAI-2 ground connection. It is very important that the DAI-2 ground connection be
connected to a good quality earth-ground for this protection to work. Failure to do this could result in a
painful or lethal shock to anyone in electrical contact with the DAI-2 if a high voltage were present on the
telephone line from lightning, etc.
DAI-2 Installation page 3. 4