Specifications

Programming Guide 2-7

ESG Family Signal Generators Programming Commands and Examples

:AM Subsystem

The amplitude modulation subsystem is used to set the modulation controls and the

parameters associated with amplitude modulated signals.

Amplitude Modulation Source

:AM[1]|2:SOURce INT[1]|EXT1|EXT2

:AM[1]|2:SOURce?

This command sets the source that will generate the amplitude modulation. The choices

are Internal Source 1, External Source 1, or External Source 2. You can choose

internally-generated amplitude 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 V

input is required for calibrated AM depth 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

Amplitude Modulation State

:AM[1]|2:STATe ON|OFF|1|0

:AM[1]|2:STATe?

This command toggles the amplitude modulation on or off for whichever AM path

configuration (

AM Path 1 or AM Path 2) you have selected. The choices are On (1) or Off (0).

Notice, however that although you can turn on amplitude modulation with this command,

the RF carrier is modulated by the enabled modulation only when you have also set

Mod On/Off to On. Whenever amplitude modulation is enabled, the AM annunciator is

turned on in the display.

There are two paths for AM modulation which can be simultaneously enabled as long as

they use different sources (Int, Ext1, or Ext2).

AM Path 2 is limited to a maximum rate of

1MHz.

AM Path 2 must be set to a deviation less than or equal to AM Path 1. The

modulation signals from both paths are summed internally for composite modulation.