Hello flofish,
I found this in the manual for the 6713:
You can calculate the least significant bit (LSB), or the minimal allowed voltage change, on a voltage output on your AO Series device as follows:
LSB = output voltage range/2^resolution of your device
where the output range is determined by your reference selection. Using AO EXT REF, you can reduce the output voltage range and lower the LSB, the minimum allowed voltage change.
You can connect each DAC to the device internal reference of 10 V or to the external reference signal connected to the external reference (AO EXT REF) pin on the I/O connector. This signal applied to AO EXT REF should be within ±11 V of AO GND. You do not need to configure all channels for the same mode. Using AO EXT REF to reduce the output voltage range results in a higher resolution at the adjusted range.
I hope this helps!
E.Lee
Eric
DE For Life!