Stimmen - 2, Durchschnittliche Bewertung: 3 ( )

Hersteller: Agilent Technologies Dateigröße: 3.05 mb Dateiname: Unterrichtssprache:

4.2.3. Numeric Editor The numeric editor is shown in the control window at locations where numeric values are set. The Acqiris Numeric Editor enables easy input of numeric values, particularly those ranging over many decades. The numeric value can be changed in multiple ways. A number can be typed directly into the white number display area or alternatively, the Acqiris Numeric Editor may be used. In order to use the Acqiris Numeric Editor, click on the green numeric editor icon at the left of the number display. A numeric editor control will appear as shown. The methods to change the values are: 1. Increment or decrement any digit with the arrow buttons by pressing the increment or decrement button. When the button is held down, the digit will continue to increment or decrement automatically. 2. Click on a digit and drag the mouse up or down to increase or decrease the value. 3. Type a new value with the keyboard for any highlighted digit. The value is constrained to fall within its allowed range whenever the user attempts to enter a larger or smaller value. Digits that are below the resolution or granularity cannot be modified. A message is displayed in the numeric setting control window when the pointer is positioned over a digit that is below the allowed granularity and cannot be changed. 4.2.4. Keyboard shortcuts Two shortcuts have been defined to simplify applying changes of a parameter to a group of channels. When the mouse is over the control of a channel parameter - .. 's' can be used to set the current value to all channels of all available instruments .. 'c' can be used to set the current value to all channels of the current instrument. Other shortcuts are: .. 'Ctrl-S' as a synonym for 'Save Setup' .. 'Ctrl-R' as a synonym for 'Recall Setup' .. 'Ctrl-C' as a synonym for Calibrate all (active) instruments' .. 'Ctrl-E' functions as a toggle between 'Internal Clock' and 'External Clock' operation. 4.2.5. Input Voltage Scale, Offset and Coupling Settings for input voltage scale, offset, coupling and impedance are available in the portion of the control panel shown to the right. The selected channel is shown on the upper section of the display. Only this channel will be affected by changes in any settings on the control panel. The input voltage scale is set by one of three possible methods: 1. Clicking on the white numeric display of the voltage scale will show a pop-up list. Select the desired gain setting with the mouse pointer. 2. Clicking on the Decrement / Increment icons will step the voltage scale up or down to the next level for each click of the mouse. 3. Clicking Max / Min will toggle to the least sensitive gain setting or to the most sensitive gain setting. The input Coupling can be set for AC or DC. The selected setting is shown as an actuated indicator with a green backlight. AC coupling blocks DC signal components from the input. The AC coupling mode acts as a high pass filter passing frequencies above 10 Hz. In DC coupling all frequency components are passed through the input. The input voltage offset control applies an offset to the input amplifier in order to better digitize and display signals offset away from 0 volts. Signals riding on a DC level can be most accurately characterized when the offset is adjusted so that the acquisitions are made about the midpoint of the digitizer’s Full Scale Range, and when as much of the 8-bit ADC range is used as possible. The ability to select an offset voltage enables accurate measurement when offsets are present in the signal. The Impedance selection allows the user to choose the appropriate internal input termination of 50 . or 1 M.. The Adv button in this section gives access to the choice of hardware bandwidth limits for the channel. 4.2.6. Trigger Trigger characteristics are set using the settings in the control panel Trigger section. The trigger source setting can be either Internal (trigger on any one of the input channels) or External (trigger on an external input). The trigger source is indicated in the display by the name appearing under Source. In order to select the trigger source, click the drop-down source menu in the trigger Source section of the control panel and choose the desired one. Notice that, for most digitizer models, when external trigger is selected, the controls for the trigger termination, 50 . or 1 M., are enabled in the Coupling section. Select the desired termination for the external trigger. The Coupling section also contains a selection for AC or DC coupling. AC coupling on the trigger sets the trigger circuit to an AC Low Frequency Reject mode. Use the Level section to set the desired trigger level. The relationship between coupling, trigger source, and trigger level was discussed in section 3.4.3 Trigger Level. The DC271-FAMILY digitizers have two adjustable trigger levels associated with the range of the window trigger. The trigger Delay setting positions the acquisition with respect to the trigger. Pre-trigge...

Herunterladen

Geben Sie zwei Ziffern: