User`s manual

Using the Combined
List with the Signed
Number Format
This section shows how to setup the AFG to receive a combined list in the
Signed number format and how to generate the list from voltage values.
Transferring the List in
the Signed Number
Format
With the AFG set to receive codes in the Signed number format, it receives
the codes in 16-bit two’s complement numbers. Use the
[SOURce:]ARBitrary:DAC:FORMat SIGNed command to select the format.
Determining Codes in
the Signed Number
Format
For outputs into matched loads and with the amplitude set to maximum
(+5.11875V), the following codes generate the following outputs:
Code 0 outputs 0 V
Code -32768 outputs -5.12 V or negative full scale voltage
Code +32760 outputs +5.11875 V or positive full scale voltage
To calculate combined DAC codes from voltage values, use the formula:
Code = (voltage value / .00125) shift left by 3
For example, to output -2V:
DAC Code = (-2 / .00125) shift left by 3 = -12800
To output a marker at a particular point of a waveform, add “2” to the
combined list DAC code value of the point. For example, to add a marker
bit of a point with a voltage value of 5 V:
Code = ((5 / .00125) shift left by 3) + 2 = 32000 + 2 = 32002
240 High Speed Operation Chapter 7