Analog Discovery Scope and Waveform Generator Edited 11/15/2016 by Eric Scotti & DGH Specifications The Analog Discovery contains several devices but we will likely only use the 2 channel oscilloscope (Scope) and one of the waveform generators (Wavegen). All of the inputs to the Analog Discovery have an impedance of 1MΩ. The Scope has bandwidth of 5MHz at 100MS/s with 14-bit resolution. It can only accept voltages between -25V & 25V. The Wavegen can only produce voltages from -5 to 5 V. All of the Analog Discovery s internal devices are controlled with the WaveForms2015 software - see icon in Figure 1. The hardware interface to the Analog Discovery is shown in Figure 2. There are two Scope inputs (Ch1, Ch2), a Wavegen output (Sig Out), and a selectable input/output trigger (Trig1). Figure 1 WaveForms2015 icon Figure 2 Connection Plate Quick Start Guide The following are instructions for using the most common setup: 1. Open WaveForms2015. 2. From the Welcome Screen open a Scope and Wavegen tab 3. On the Wavegen tab set the following: a. Set Synchronization to Auto Synchronization (starts on No Synchronization.) b. Set Trigger to none c. Set Repeat to infinite 4. On the Scope tab set the following: a. Set Run: to repeated b. Set Source to Wavegen 1 5. Hit Run on both scope and wavegen tabs to start collecting data and outputting signal.
Full Manual Getting Started Use the icon to open the program. The welcome screen, shown in figure 3, will appear. Figure 3 Waveforms Welcome Screen From the welcome screen you can open all of the instruments supported by the Analog Discovery (scopes, function generators and others instruments not currently connected to our hardware interface.) To open an instrument, click on the appropriate tab on the left of the screen. For example, #1 in figure 3 will open the oscilloscope and #2 will open the wave generator. The device window will be displayed and a tab will appear at the top for easy switching among instruments see #3 in figure 3. #4 in figure 3 opens the help tab with more detailed documentation.
Scope Details The open Scope tab is shown in Figure 4. The numbers on the screen identify highlighted features see the corresponding numbers below. Figure 4 Scope Display 1. Main menu bar. a. File Export saves data as a.txt or.csx file. An image of the Scope screen can also be saved. Note File save project, saves the Scope configuration but it does not save data. b. View AddXY adds an XY graph to the display in addition to the YT 2. Displays the status of the Scope (armed, trig d, off, etc.) 3. Control toolbar is immediately above the display. From L to R the options are: a. Single: collect data for one length of the display one trigger. b. Start/Stop: begins/ends continuous data collection repeated triggers c. Run: Changes how data is displayed or taken, i. 1 st drop down controls display/data collection. Typically, you will want to use the default (repeated) ii. 2 nd drop down controls the Scope trigger: 1. Auto: runs continuously with no trigger but syncs to a trigger when one is provided. 2. Normal: requires a trigger for the Scope to run. Nothing will happen until there is a trigger signal.
3. None: No trigger required, the Scope just runs and collects data with no synchronization d. Source: Use this to select what the Scope triggers on. Typically you will want to select Wavgen. Remember, whatever you select here is only valid if the Scope is set to Auto or Normal in the Run menu e. Condition (only applicable if Source is set to ch1 or ch2): Sets the slope of the selected trigger signal. f. Level (only applicable if Source is set to ch1 or ch2): Sets the minimum voltage required to trigger the Scope 4. Displays all open tabs and allows navigation among them; viewable from all tabs and can be used to start/stop the Scope from other tabs 5. Time Box: changes time (x) axis with the following options a. Position: Sets the location on the screen of T=0. Default = 0 in the center. b. Base: Sets the time/division on the display. This is call Scale on the Techtronic scopes. 6. Channel Boxes: Adjusts the display of a channel with the following options: a. Check Box: turn the channel on or off b. Offset: Sets the location of V=0 (ground) on the display for that channel (default = 0V in the center) c. Range: Sets the volts/division for that channel d. Gear symbol: Opens up the channel options (Figure 5). 1: changes the color of the displayed line 2: turns on or off noise, unchecking this gives better displays 3: Change channel names on the display and in the math functions Figure 5 Channel Options
Wavegen (Function Generator) Figure 6 Wavegen Display The Wavegen tab is shown in Figure 6 with the important features highlighted. The numbers below correspond to the numbers on the screen. 1. Main menu bar a. File Export saves data as a.txt or. csx file. An image of the Wavegen screen can also be saved. Note File save project, saves the Wavegen configuration but it does not save data this is similar to save setup on the Techtronic scopes. 2. Control toolbar (immediately below main menu bar): From L to R the options are: a. Run all/stop all: starts or stops all output channels of the function generator. Note: we only use channel 1. b. Selects active channels; select channel 1. c. Synchronization drop down menu: i. No Synchronization = no trigger options, device controlled manually with Run & Stop only ii. Independent = allows both channels to be run with separate trigger options. iii. Synchronized = both channels will run and stop together, only one trigger options is provided to run both channels; iv. Auto Synchronization (suggested) = Synchronized, with the addition that the run time is automatically adjusted to the longest period of the two channels. This makes it easy to trigger the Scope with the Wavegen.
3. Channel toolbar immediately above the display. From L to R the options are: a. Run/Stop: begins/ends Wavegen output; note: enable should be checked b. Changes input options for Wavegen, for our labs the default option of Simple should suffice. c. Trigger: Sets what the Wavegen triggers on. We will typically want none d. Wait: Sets how long the Wavegen will wait after receiving a trigger before outputting its signal e. Run: Sets how long the Wavegen will output a signal. (Auto Synchronization sets this automatically.) f. Repeat: Sets how many times the Wavegen should repeat its wait-run cycle before stopping - typically this can be set to infinite. g. Repeat Trigger: Checking this requires the Wavegen to receive a trigger signal to start a new cycle Note: depending upon the selected synchronization option, c-g may appear in the control toolbar instead. 4. Lists all open tabs and allows navigation between them; viewable from all tabs and can be used to start/stop the Wavegen from other tabs 5. Wavegen Function options: Sets the output of the Wavegen with the following options: a. Type: Selects the wave form. (e.g. sine, triangle, or square wave) b. Frequency: Selects the frequency of the wave form. c. Amplitude: Selects the zero to peak voltage of a wave form. Note: this is half the peak-to-peak voltage. The zero point may be offset (see #d.). d. Offset: Adds a DC component to the output voltage of the wave form e. Symmetry: Allows the selected wave form to be distorted. For our labs this should always be left on default f. Phase: Sets the starting (t=0) point of the signal Triggering Trig1 can be set as an input or an output with the Settings Options on the main toolbar (see Figure 7). Trigger signals from an external device can be sent to the Scope and/or the Wavegen. Alternatively, Trigger signals from the Scope or the Wavegen can be sent to external devices. External devices = hardware not included in the Analog Discovery. Note, sending an external trigger from the Wavegen is a bit tricky, see Further Details of Trigger Out Signals below. In our labs we will usually take advantage of the Analog Discovery s internal trigger function to trigger the Scope with the Wavegen. To do this, set the Wavegen to Auto Synchronization with the trigger set to none. On the Scope, set the Source to Wavegen 1. Now the Scope will continuously sync to the Wavegen no matter what is displayed on the Scope. This is a very convenient configuration.
Figure 7 Options Menu Syncing Two Analog Discoveries To sync the Scopes of two Analog Discoveries together, we suggest the following. 1. Set the Wavegen on one of the Analog Discoveries to Auto Synchronization and set it to your desired wave form, amplitude and frequency. 2. Set the Scope in the same Analog Discovery to trigger on Wavegen 1 3. On the same Analog Discovery set Trig1 to output the Scope trigger. 4. On the second Analog Discovery set Trig1 to input. 5. Connect the Trig1 s from both Analog Discovery s. 6. Set the Scope on the second Analog Discovery to trigger on external 1. Note: using two Analog Discoverys on the same computer requires opening two distinct instances of Waveforms2015. Further Triggering Details The Scope and Wavegen output trigger signals are as follows: Scope: Puts out a 3.3V TTL like pulse synchronized with the time required to scan one screen. Wavegen: Normally puts out a 3.3VDC signal while running it does not put out a TTL like pulse. The scope trigger is close to a typical TTL output trigger except that it is 3.3V instead of the standardized 5V. The Wavegen output trigger is highly unusual, unless the Wavegen is setup very specifically the output trigger is simply a 3.3DC voltage this is not a usable trigger. To get a usable trigger out of the Wavegen, set the Wavegen to Auto Synchronization. In this configuration, the run time equals the time required for one period of the signal, the wait time is set to 0 and the repeat is set to infinite. In this configuration the Wavegen will put out a very briefly drop in its 3.3VDC signal at the start of each run period. It only drops to ~2.5V but it is enough to use as a trigger.