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3.2 Display Window
The MODEL 4040DDS has a graphic LCD display that can display up to 122 x 32 dots. When you power-on the unit
the SINE is selected and its current settings appear in the display. The bottom displays a status line that corresponds to
the function, parameter or mode displayed selected.
3.3 Front Panel Controls
The front-panel controls select, display, and change parameter, function, and mode settings.
Use the rotary input knob and the cursor movement keys to enter data into the waveform generator.
To change a setting:
1.Press the key that leads to a required item.
2. Move cursor using cursor keys to the appropriate position in the numeric field (if applicable).
3. Use the rotary input to change the value of the displayed item. Changes take effect immediately.
The following subsections describe the function of each front panel key and connector.
3.4 Connectors
The function generator has all BNC connectors on the front panel where you can connect coaxial cables. These
coaxial cables serve as carrier lines for input and output signals delivered to and from the function generator.
Output Connector
Use this connector to transfer the main output signal from the function generator.
Trig In Connector
Use this connector to apply an external trigger or gate signal, depending on the waveform generator setting, to the
generator. This connector is also the input to the build-in counter, activated by pressing the COUNT pushbutton.
Sync Out Connector
Use this connector to output a positive TTL sync pulse generated at each waveform cycle.
Modulation In Connector
5V p-p signal for 100% modulation, 10Kohms input impedance with DC - >20 KHz bandwidth.
3.5 Output Connections
The waveform generator output circuits operate as a 50 ohms voltage source working into a 50 ohms load. At higher
frequencies, non terminated or improperly terminated output cause aberrations on the output waveform. In addition,
loads less than 50 ohms reduce the waveform amplitude, while loads more than 50 ohms increase waveform
amplitude.
Excessive distortion or aberrations caused by improper termination are less noticeable at lower frequencies, especially
with sine and triangle waveforms. To ensure waveform integrity, follow these precautions:
1.Use good quality 50 ohms coaxial cable and connectors.
2. Make all connections tight and as short as possible.
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