Tabor Electronics 5251, Руководство пользователя

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TE5251
User Manual
4-48
4-8 shows how to prepare the 32-bit word for the FM modulating waveform.
There are a number of points you should be aware of before you start preparing the data:
1. The FM function is shared by both channels
2. The number of bytes in a complete FM modulating waveform data must divide by 4. The Model 5251
has no control over data sent to its FM waveform during data transfer. Therefore, wrong data and/or
incorrect number of bytes will cause errors
3. The LSBit on the last byte sets marker position. “0” = sets no marker and “1” sets marker. You can set
as many markers as you want.
4. The SYNC output serves as marker output when you have the 5251 set to operate in FM mode.
Normal SYNC level is TTL low. The SYNC output is set to TTL high at the position of the marker. This
way you can use the SYNC output to mark frequency occurrences during FM operation.
5. Data download is terminated with the MSBit of the last byte set to 1.
The following sequence should be used for downloading arbitrary FM Waveforms:
1. Prepare your FM waveform data points using the following relationship:
N = Frequency[Hz] x 14.31655765
2. Use an I/O routine such as ViMoveAsync (from the VISA I/O library) to transfer binary blocks of data
to the generator.
Parameters
Name Type Description
<binary_block
> Binary Block of binary data that contains information on the
arbitrary modulating waveform.