User`s manual

Frequency-Shift Keying
Frequency-shift keying (FSK) changes the frequency of the output
waveform or sample rate based on the signal level of the frequency-shift
keying control source. FSK frequencies can range from 0.0 Hz to 10 MHz.
The command subsystems associated with frequency-shift keying include:
• [SOURce:]ROSCillator
• TRIGger
• [SOURce:]FREQuency[1]
–
FSK mode and related commands
FSK Using the
“FSK” Control
Source
The FSK1 program shows the basic steps involved in setting up and using
the frequency-shift keying function of the AFG. A 5 V, 1 MHz square wave
control signal is applied to the AFG’s front panel “FSK” port. Output
frequencies of 5 MHz and 10 MHz occur as the level of the 1 MHz signal
changes.
Note When the frequency shifts, there is a delay of 20 reference oscillator clock
cycles before the frequency is active. This delay occurs with all reference
oscillator sources.
Using the flowchart in Figure 4-1 as a guide, the steps of this program are:
1. Select the 42.9 MHz reference oscillator
[SOURce:]ROSCillator:SOURce <source>
2. Select the frequency generator which allows frequency-shift keying
TRIGger[:STARt]:SOURce <source>
3. Select the frequency-shift keying mode
[SOURce:]FREQuency[1]:MODE <mode>
4. Select the FSK frequencies
[SOURce:]FREQuency[1]:FSKey <frequency1>,<frequency2>
5. Select the FSK control source
[SOURce:]FREQuency[1]:FSKey:SOURce <source>
6. Set the output function
[SOURce:]FUNCtion[:SHAPe] <shape>
Chapter 4 Sweeping and Frequency-Shift Keying 147