unD4I / unD4I-L
User Manual
Attero Tech LLC 2015
Page 11
614-00020-06
2.4 – Logic Inputs (unD4I-L only)
The logic inputs of the unD4I-L can be used as analog inputs to measure a voltage
or as digital inputs. In either case the maximum input voltage must be between
0V and 3.3V. The input connections provide both a ground reference and a 3.3V
supply. The current limited 3.3V supply connection is provided on the rear panel
near the logic inputs for easy access. Note also that only a single ground is
required for logic input signals originating from the same device.
All programmable logic input feature configuration is performed using the unIFY
Control Panel software.
2.4.1 – Analog-Input Mode
When used as an analog input, the voltage applied must be between 0V and 3.3V. The unD4I-L will convert that into a
12-bit number where 0 = 0V and 4095 = 3.3V. A typical application for using an analog input may be a volume control
where the volume is controlled by a potentiometer. The position of the potentiometer can be measured by the unD4I-L
and a control system can read the value and adjust the volume accordingly.
Figure 9 - Analog Mode Interfacing
2.4.2 – Digital Input Mode
When the logic inputs are used as digital inputs, the input turns on when the input voltage rises above 1.85V and will
turn off again when the voltage falls below 1.2V. Typical drive circuits could be simple switches or open collector and
push-pull logic outputs from another device.
Figure 10 - Digital Mode Interfacing
A typical use case for the logic inputs are the use of a latching switch used to indicate the mute state of the microphones
interfaced to the unD4I-L to a networked audio DSP (or control system) in the audio system. When the end user closes
the switch a network message cab be configured to be sent to the DSP. When the switch closes or opens, the change in
mute state is indicated back to the DSP or control system.
Figure
8
- Logic I/O Pinout
