The LabJack data acquisition modules are flexible I/O modules for getting signals in to and out from your computer. The family features wide software support with drivers and code examples for a range of platforms and languages. The U3 is the most economical member of the family but it's packed with features.

The LabJack modules come with Windows software that allows you to be quickly up and logging and graphing data.

Flexible I/O:

The 12 flexible I/O lines (FIO and EIO ports) on the LabJack U3-HV can be individually configured as digital input, digital output, or analog input. In addition, up to 2 of these lines can be configured as timers, and up to 2 of these lines can be configured as counters.

The first 4 flexible I/O lines (FIO4-FIO7) appear on built-in screw terminals. The other 8 flexible I/O lines (EIO0-EIO7) are available on the DB-15 connector on the base fo the unit. The optional CB15 board breaks these out to screw terminals.

Analog Inputs:

The LabJack U3 has up to 16 analog inputs available on the flexible I/O lines. Single-ended measurements can be taken of any line compared to ground, or differential measurements can be taken of any line to any other line.

Analog input resolution is 12 bits. The range of single-ended low-voltage analog inputs on the U3-LV is typically 0 to 2.4 V or 0 to 3.6 V, and the range of differential analog inputs is typically ±2.4 V (pseudo bipolar only). For valid measurements, the voltage on every flexible I/O pin, with respect to ground, must be within -0.3 to +3.6 V.

On the U3-HV, the first 4 flexible I/O of the U3-LV (FIO0-FIO3) have been replaced with dedicated high-voltage analog inputs. The input range of these channels is ±10 volts or -10 to +20 volts. The remaining 12 flexible I/O are still available as described above, so the U3-HV has 4 high-voltage analog inputs and up to 12 low-voltage analog inputs.

Command/response (software timed) analog input reads typically take 0.6 to 4.0 ms depending on number of channels and communication configuration. Hardware timed input streaming has a maximum rate that varies with resolution from 2.5 ksamples/s at 12-bits to 50 ksamples/s at about 10-bits.

Analog Outputs:

The LabJack U3 has 2 analog outputs (DAC0 and DAC1) that are available on the screw terminals. Each analog output can be set to a voltage between 0 and 5 V with 10-bits of resolution.

The analog outputs are updated in command/response mode, with a typical update time of 0.6 to 4.0 ms depending on communication configuration. The analog outputs have filters with a 3 dB cutoff around 16 Hz, limiting the frequency of output waveform to less than that.

Digital I/O:

The LabJack U3-HV has up to 16 digital I/O channels. 12 are available from the flexible I/O lines, and 4 dedicated digital I/O (CIO0-CIO3) are available on the DB15 connector. Each digital line can be individually configured as input, output-high, or output-low. The digital I/O use 3.3 volt logic and are 5 V tolerant.

Command/response (software timed) reads/writes typically take 0.6 to 4.0 ms depending on communication configuration. The first 16 digital inputs can also be read in a hardware timed input stream where all 16 inputs count as a single stream channel.

Timers:

Up to 2 flexible I/O lines can be configured as timers. The timers are very flexible, providing options such as PWM output, pulse/period timing, pulse counting, and quadrature input.

Counters:

Up to 2 flexible I/O lines can be configured as 32-bit counters.

I/O Protection:

All I/O lines on the U3 are protected against minor over voltages. The FIO lines can withstand continuous voltages of up to ±10 V, while the EIO/CIO lines withstand continuous voltages of up to ±6 V.

High Channel Count Applications:

By using USB hubs, many LabJacks can be interfaced to a single PC, providing an inexpensive solution for high channel count applications.