The openDAQ features a mini-USB connector for power
and communications, two screw terminal connector plugs
for I/O, and an LED indicator, as shown in Fig. 2. In relationship
to others DAQs, openDAQ presents excellent features.
Table 1 shows a comparison with the popular National
Instruments NI USB-6009. In general openDAQ presents
better characteristics. Only the sample rate is lower. However
for the large majority of signal to be measured the frequency
is less than 1 kHz so a sample frequency of 20 kHz