HP (Hewlett-Packard) PCI-9111DG/HR Manual De Usuario

Operation Theorem 

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33 

4.4 

D/A Conversion 

The PCI-9111 has one analog output channel.  The signal range can be 
uni-polar or bi-polar which are set by JP1. 

 

To D/A Output  

D/A Converter 

- 
+ 

-10V 
Ref In 

Analog GND  

Pin- 30 (DA Out)  

 

 

The operation of D/A conversion is simpler than A/D operation. You only 
need to write digital values into the D/A data registers and the 
corresponding voltage will be output from the DA Out (pin-30 of CN3).  
Refer to section 3.15 for information about the D/A data registers. The 
mathematical relationship between the digital data DAn and the output 
voltage is formulated as following: 

 

  = 

span x  DAn / 4096 

 

 

– Unipolar 

     

= 

span x  DAn / 4096 + (-10) 

 

– Bipolar 

where span is the span in volts. If your output range is -10V~10V (Bipolar), 
then span is 20; if your output range is 0~10V (Unipolar), then span is 10. 
The V

 is the output voltage, and the DAn is the digital data value in the 

D/A data registers. 

Before performing the D/A conversion, users should care about the D/A 
output range which is set by the JP1. Please refer section 2.4 for jumper 
setting.