8-Channel Isolated 4-20 mA current sinking D/A Board

The DNA-AO-319-420, DNR-AO-319-420 and DNF-AO-319-420 arefully isolated, high-precision, 8-channel analog current output boardscompatible with UEI’s popular “Cube”, RACKtangle and FLATRACK I/Ochassis respectively. The boards offer full 16-bit resolution and guaranteemonotonicity over the entire operating temperature range. EachDNx-AO-319-420 channel provides an output range of 4-20 mA (sinking).For applications requiring a sourcing 4-20 mA output, please refer to theDNx-AO-318-020. For applications requiring voltage outputs please referto the DNx-AO-308 or DNx-AO-318 series boards.

The DNx-AO-319-420 provides extensive built-in-test diagnostics. An on-board A/D converter on each channel allows the user to monitor bothoutput voltage and current. A solid state relay on each output allows theD/A channel to be disconnected from the field I/O so that a completeboard self-test can be completed without driving the circuitry connectedto the outputs. This relay automatically disconnects the D/A output inthe event of an external fault condition such as a short to ground or a DCpower supply. The output relay may also be opened to simulate an opencircuit/broken cable failure.

All 8 channels may be configured to update simultaneously, or they maybe updated one at a time as data is written. A 1024 sample FIFO allowseach D/A to be updated at 10 kHz without data loss. Note that the outputcircuit only sinks current. Settling time for current increases will be low,but settling time for current decreases is largely set by the reactance ofthe sensor/cable combination (essentially a pull-up configuration).

Software included with the DNx-AO-319-420 provides a comprehensive,yet easy-to-use API that supports all popular Windows programminglanguages as well as supporting programmers using Linux and mostreal-time operating systems including QNX, RTX, VXworks and more.Finally, the UEIDAQ Framework supplies complete support for thosecreating applications in data acquisition software packages such asLabVIEW, MATLAB/Simulink or any application which supports ActiveXor OPC servers.