Specifications

Programming Guide 2-23
ESG Family Signal Generators Programming Commands and Examples
:FM Subsystem
For example, if you choose a carrier frequency of 400 MHz, multiply 0.5 times 10 MHz.
This results in a 5 MHz maximum peak deviation.
Notice that the new value of FM deviation applies only to whichever FM path
configuration you have currently selected. Also, whenever
FM Path 1 is used with FM Path 2,
the deviation for
FM Path 1 must be greater than or equal to the deviation for FM Path 2.
*RST Value: 1.0 kHz
Frequency Modulation Deviation Coupling
:FM[1]|2[:DEViation]:TRACk ON|OFF|1|0
:FM[1]|2[:DEViation]:TRACk?
This command toggles the FM deviation coupling on and off. Turning on FM deviation
coupling links the FM deviation values of
FM Path 1 and FM Path 2. When the values are
coupled, any change you make to one FM deviation value is applied to both FM deviation
values.
*RST Value: Off
Frequency Modulation Source
:FM[1]|2:SOURce INT[1]|EXT1|EXT2
:FM[1]|2:SOURce?
This command sets the source that will generate the frequency modulation. The choices
are Internal Source 1, External Source 1, or External Source 2.
You can choose internally-generated frequency modulation or select an externally-applied
signal from either the EXT 1 INPUT or EXT 2 INPUT connectors. The internal modulation
is always AC-coupled. For the externally-applied signals, you can choose between AC- and
DC-coupled modulation. A 1.0 Vpk input is required for calibrated FM deviation settings.
The EXT 1 LO/HI and EXT 2 LO/HI display annunciators will turn on if the peak input
voltage differs from 1.0 Vpk by more than 3%. (The LO/HI annunciators only function for
AC-coupled external inputs.)
The internal and external 1 and 2 sources have multiple uses. You can use them for
amplitude, frequency, and phase modulation. For burst modulation, you can only use the
external 1 source and you must use the external 2 source for pulse modulation. However,
any given source can only be routed to one enabled modulation at a time. If, for example,
you were using the external 1 source in a frequency modulation configuration for
FM Path 1, and then you configured AM Path 2 to also use the external 1 source, the signal
generator would turn off
FM Path 1 and assign the external 1 source to your AM Path 2
configuration. Notice that for these purposes the external 1 AC-coupled source is the same
as the external 1 DC-coupled source and the external 2 AC-coupled source is the same as
the external 2 DC-coupled source.
*RST Value: Internal