Frequency modulation (and FSK)
These commands enable you to select frequency modulation either as a single modulation or as the sum of two signals, to set the deviation rate, to switch the modulation on and off and to perform DC FM nulling. (For the latter, ensure that a ground reference is connected to the EXT MOD INPUT socket before you implement the command.) You can set the modulation oscillator frequency and select between sine, triangle and square waveforms. Also the phase difference of modulation oscillator channel 2 relative to channel 1 can be offset in degrees. Both deviation rate and modulation oscillator frequency can have their step sizes set and then be stepped up or down. And after having adjusted the deviation rate or the modulation oscillator frequency you can either return to the reference (rate or frequency) or make the current value the new reference.
FM or FM1 or FM2 | Set FM Deviation (short form) |
| |
:DEVN | Set FM Deviation |
:INC | Set FM step size |
Data type : | Decimal Numeric Program Data |
Allowed suffices : | Any one of: GHZ, MHZ, KHZ or HZ |
Default suffix : | HZ |
:<src> | Select modulation source where <src> is any one of: INT, EXTAC, |
| EXTALC, or EXTDC |
:ON | Turn FM ON (locally) |
:OFF | Turn FM OFF (locally) |
:UP | Go UP one step |
:DN | Go DOWN one step |
:RETN | Return to original setting |
:XFER | Transfer current value to be the new setting |
Data type : | None |
Allowed suffices : | None |
Default suffix : | None |
Examples: | FM:DEVN 25KHZ;INT;ON |
| FM1:DEVN 15KHZ;INC 1KHZ;EXTDC |
:MODF | Set FM modulation oscillator frequency (short form) |
:VALUE | Set FM modulation oscillator frequency |
:INC | Set FM modulation oscillator frequency step size |
Data type : | Decimal Numeric Program Data |
Allowed suffices : | Any one of: GHZ, MHZ, KHZ or HZ |
Default suffix : | HZ |
:UP | Go UP one step |
:DN | Go DOWN one step |
:RETN | Return to original setting |
:XFER | Transfer current value to be the new setting |
:SIN | Select sinusoidal waveform |
:TRI | Select triangle waveform |
:SQR | Select square waveform |
Data type : | None |
Allowed suffices : | None |
Default suffix : | None |
