Models DA12-8 and DA12-16 are full-size cards that can be installed in any long I/O slot of PC-AT class computers. These cards provide eight and sixteen 12-bit- resolution analog outputs respectively at a 37-pin male Sub-D connector. Analog output channels can be individually switch configured for any of the following voltage ranges:
- 0 to +2.5V
- 0 to +5V
- 0 to +10V
Type AD7237 double-buffered dual DAC chips are used. Data are transferred from the computer into outer registers a byte at a time and transferred into inner registers a word at a time. The analog outputs can be updated either independently or simultaneously. In order to prevent inadvertent outputs at system power-on, the reference voltage to all DAC’s is set to zero volts. Then, after all DAC’s have been loaded with the desired initial values, a software command can be used to switch this reference voltage to its nominal value. Similarly, a software command can be used at any time to set the reference voltage to zero causing all DAC outputs to be zero volts.