************************************************* * Timebase Main/Delayed * ************************************************* 1. FFT ------------------------- FFT is now reachable from the Timebase menu and no longer from the Math menu. The FFT-submenu will appear when pushing the FFT-button once more. 2. USTB-Submenu ------------------------- Here You can make some settings for the ultra slow timebases. ************************************************* * USTB Menu * ************************************************* 1. USTB-Mode ------------------------- - Roll Forward -> Actual timepointer rolls through the memory and jumps back to the start when reaching the end. After jumping back the old values in the memory will be overwritten. - Roll Reverse -> Rolls from end to the memory start and jumps back to the end when reaching the start. After jumping back the old values in the memory will be overwritten. - Shift Forward -> Shifts the whole signal through the memory to the end and out of the memory. Signal end which is shifted out of memory is lost. Actual time pointer (signal start) is always on the left side. - Shift Reverse -> Shifts from the right side to the left. Actual time pointer (signal start) is always on the right side. 2. USTB Display ------------------------- This function is available only for roll mode. - Permanent -> The displayed memory windows follows the time pointer permanently point for point. - Stepwise -> The displayed memory window always jumps to the next position when the time pointer reaches the window edge. The step width is one grid width (12 divs) at one step. 2. Buffer Size ------------------------- Sets the buffer size which is used for signal shifting/rolling.Available are 8kbyte/16kbyte/32kbyte for roll mode and 8kbyte/16kbyte for shift mode. All buffer sizes are supported by memory scrolling. Not full supported at this time is for 32kbyte buffer size the recall/overlay function and the csv-dump function in the quick print menu. There will be transmitted only 16kbyte maximum of the buffer, the rest will be cut off. ************************************************* * Channel 1 - 4 * ************************************************* 1. AC/DC (GND) coupling ------------------------- Pushing the button switches between AC/DC and sets the focus to the coupling button. Using the mainwheel opens a popup menu with GND/AC/DC as choice. Please notice that the GND function is only virtual. No real signal coupling to GND is done! 2. Center Channel ------------------------- Sets the virtual zero voltage (Y-position) to the screen middle. 3. Dispatch Channel ------------------------- Depending on the number of active channels the zero levels are dispatched on the screen with the focus to have maximum place for every channel. Since FW-version 2.19 beta the dispatch function got a DC offset detection which adjusts the zerolevel depending on the offset. (for digital signals etc.) ************************************************* * Acquire * ************************************************* 1. Logic Processor ---------------------- Shows the signal under a logical point of view. That means the level is normed to one div and shows the state (high or low) only. Depending on the selected logic family the thresholds for switching between the levels is set. Also the triggerlevel is is preset to the middle between the switching points to guarantee a stable signal. In case of RS232 which is a negative logic, the signal is converted to the logical output (negative signal means logical high or 1). 2. Average ---------------------- calculates the average value using the samples laying before the actual value (in the past). This may decrease the noise. 3. Noise Filter ---------------------- engl. - Filter characterisics (cutoff frequency) at 1GSa/s: germ. - Die Filter haben folgende Eckfrequenzen bei 1GSa/s: Proprietary algorithm - Smooth ca. 80 - 90Mhz at TB = 50ns/div -> in all other TB cutoff frequ. is half virtual sample rate that means lossless! - Strong ca. 30 Mhz at TB = 50ns/div -> because of overlapping here is a loss of bandwidth in all other TB cutoff frequ. is 0.35 * sample rate IIR algorithm (cutoff at timebase <= 50ns/div) - IIR 1 Stage ca. 70 - 80Mhz IIR-filter with 1 stage and coefficient 0.5 - IIR 2 Stage ca. 35 - 40Mhz IIR-filter with 2 Stages and coefficients 0.5 - IIR 3 Stage ca. 20MHhz IIR-filter with 3 Stages and coefficients 0.5/0.5/0.25 - very aggressive! The IIR-filters are producing a little dc-offset depending on the noise level of the signal. The filter functions are using own memory areas for their results - what does that mean? In Stop mode You can scroll through the memory with filter switched on. Scrolling happens in the filter buffer. Filter can be switched on in Stop mode and shows effect immediately. 4. Interpolation ---------------------- 5. Peak Detect ---------------------- Determines the highest and lowest values for each sample interval, then displays all the samples between the two values, inclusive. Especially useful at slower sampling rates, Peak Detect allows you to see any extremes that occurred during the sample interval. ************************************************* * Display * ************************************************* 1. Persistent Popup Menu ------------------------------ Fade out time can be choosen: - Off -> no persistence - 1s -> persistent signal will disappear after 1s without refresh - 2.5s -> persistent signal will disappear after 2.5s without refresh - 5s -> persistent signal will disappear after 5s without refresh - 10s -> persistent signal will disappear after 10s without refresh - 25s -> persistent signal will disappear after 25s without refresh - 50s -> persistent signal will disappear after 50s without refresh - infinity -> persistence exists until display is cleared manually 2. No Display Popup Menu ------------------------------ Channels can be forced to operate in the background without displaying the trace. This maybe helpfull when using the channel as triggersource for a signal on another channel (like ext. triggering). 3. Draw Mode Menu ----------------------------- In time domain two drawing modes are available: - fast drawing with vertical pixel connection. Increases the refresh rate. - accurate drawing with line function. Signals will be displayed more accurately but the refresh rate will decrease a little bit. - pixel only, shows the real sample points only 4. FFT Display Menu ---------------------------------- FFT mode has its own display menu now which will be switched automatically depending on actual operating mode ************************************************* * Display Setup * ************************************************* 1. Grid Color Popup Menu ------------------------------ - change the grid color to the available palettes 2. Grid Lines Popup Menu ----------------------------- - solid grid lines - dotted grid lines 3. Status Layout Popup Menu ----------------------------- Choose an alternative screen layout - standard (beige background) - multiple monochrome layouts 4. QM-Cursors ------------------------------ - switch cursor display in QM mode on or off 5. OSS - Onscreen Status ------------------------------ - displays additional information within the grid area ************************************************* * Save / Recall * ************************************************* 1. Overlay Trace ------------------------------- A signal with its settings (trace) can be loaded from a coosen memory place (as Recall Trace). This loaded signal will be overlayed over the actual Signal which is adapted to the trace settings. So it is possible make a direct comparison between trace and actual signal. 2. Restore Settings ------------------------------ After choosing "Recall Trace" or "Overlay Trace" the settings from before are gone. Pushing "Restore Settings" will load the settings from before from flash. ************************************************* * Quick Print * ************************************************* 1. Choose the destinaton for the transmission ------------------------------------------------ data will be sent via RS232 to the connected PC on which the screenshot software is running data will be sent via RS232 to the connected USB-Host and there on an USB-stick or a SD-card. Infos about this project You will find here: http://sourceforge.net/apps/trac/welecw2000a/wiki/Vinculum 2. Additional function of the Quick Print button ------------------------------------------------- Double pushing the Quick Print button will trigger a screenshot without changing the menu. So You are able to make a screenshot from Your actual situation. 3. Send Measure ------------------------------------------------- Sends the measure slot values in quick measure mode or cursor mode. ************************************************* * Autoscale * ************************************************* 1. Double push option ------------------------------------------------ Pushing autoscale twice starts the slow TB search. This Option is also available in the Autoscale menu which appears after pushing the Autoscale button once (normal mode). 2. TB Search Setup ------------------------------------------------ - Trigger Source (TB search only on the channel which is the set as trigger source in the Edge menu. The voltage range is determined all active channels) - All Channels (TB search on all active channels in the order 1, 2, 3, 4. The first channel with a triggerable signal is choosen as new trigger source. The voltage range is determined on all active channels which are same or higher than the trigger source) Specifications: ---------------- Number of periods in the target timebase on the screen: - max. 10 - min. 4 Signal amplitude in the target range: - max. < 6 Div (about 10% and 90% line) - min. > 2 Div Timebases in search area: - normal 10ms - 2ns - SlowTB 500ms - 20ms Limits: -------- Max. frequency > 140MHz Min. frequency - normal 30Hz - SlowTB 2.5Hz Min. amplitude < 5mV (Pk-Pk < 10mV) DC signal offset > 25 Div in the target range Known problems: ---------------- Spikes on the signal can influence the result - especially the timebase search. Dependent on the ADC settings in the hardware menu spikes can occure due to timing problems in the FPGA while the data acquisition. So it is important for reliable results that the ADC Setup is on "Factory" for normal operation. Only for high frequency purposes the settings should be "HighFreq1" or "HighFreq2". Of course offset calibration in the "Utility" menue is a prerequisite for all operations and should be done first! Keep in mind that searching for very slow timebases (SlowTB) may take a longer time until the result is found. This is normal and can't be optimized because of the much longer acquistion time. ************************************************* * Trigger Setting (Edge) * ************************************************* 1. Auto Pretrigger ---------------------- engl. - What does it do and how does I find it? germ. - Was macht das Ding und wie finde ich es? engl. - the memory window (displayed in the memory browser) is set to the start address of the value buffer. germ. - Der für die Anzeige verwendete Speicherausschnitt wird ganz an den Anfang des Wertespeichers gesetzt engl. - the pretrigger is set to the screen middle. germ. - Der Pretrigger wird auf die Bildschirmmitte gesetzt engl. - change to edge menu and push the pretrigger softbutton on which the pretrigger time is displayed. germ. - Ins Edge Menu wechseln und auf den Pretrigger Softbutton drücken der sonst nur die Pretriggerzeit anzeigt. 2. Adjust Window ---------------------------------- Shifts the displayed memory window to the pretrigger position due to the pretrigger setting if possible. If the pretrigger is is too near to the edges, the window will be positioned at maximum left or right. 3. Trigger Source - Alternate ---------------------------------- The alternating trigger changes the trigger source to one active channel after another. This allows You to synchronise asynchron signals. Be aware, that nothing will happen if You are using "Normal" triggering and there is no signal on one of the channels. +++ if You are using alternating trigger - switch off unused channels for better performance +++ ************************************************* * Trigger Mode/Coupling * ************************************************* 1. Mode Coupling ------------------------ Pushing the Mode/Coupling button the first time will change to the Mode/Coupling menu. Every additional pushing will change the trigger mode which normally is changed by the mode pulldown menu (softbutton 1). 2. Mode ------------------------ - New trigger mode "Free Run". That means no triggering. Just running asyncronous as fast as possible without waiting for any event. Please keep in mind that single trigger will not work in "Free Run" mode because no trigger event will be recognized. - "Auto" trigger has a fixed hardware controlled timeout that forces a trigger event periodically if no real trigger event occures. This function is suitable for faster timebases but does not work convincingly with slower timebases. - "Normal" trigger only starts the signal acquisition if a trigger event occures. Otherwise nothing happens. The Signal seems to be freezed. - "Combi" trigger is a combination of "Normal" trigger and "Auto" trigger which simulates an "Auto" trigger with a software controlled timeout. It works much more stable than the standard "Auto" trigger 3. Trigger Auto Level ------------------------- Trigger Level is set to the signal middle of the active source channel. 4. Holdoff ------------------------ engl. - Range is limited to 134ms now. New count logic. Smallest step width is 8ns. Smaller steps are limited by the hardware. The 1ms range has the step width 1 µs. Display has 3 digits after the dot now. Pushing the Holdoff button multiple, switches the value in factor 10 steps. germ. - Der Wertebereich ist auf 134ms beschränkt. Die ganze Zähllogik ist komplett überarbeitet. Die kleinste Schrittweite ist jetzt 8ns. Kleinere Schritte kann die Hardware nicht abbilden. Ab 1ms ist die Schrittweite 1µs. Es gibt jetzt 3 Nachkommastellen. Durch mehrfaches Drücken der Holdofftaste kann in Faktor 10 Schritten weitergeschaltet werden. 5. More ------------------------ ---> Trigger Submenu ************************************************* * Extended Trigger Mode/Coupling * ************************************************* 1. LED 1 Setup ------------------------------------ Choose LED 1 function (left LED). - LED 1 off - Trigger armed (on when waiting for the next trigger event, off when trigger occurs) - Tek (behaviour like Tektronix scopes. On -> no trigger event, waiting) 2. LED 2 Setup ------------------------------------ Choose LED 2 function (right LED). - LED off - Triggered (only active when trigger occured and data acquisition started) - Trigger Event (also active when trigger occured and no data acquisition started like in Stop mode) - Tek (behaviour like Tektronix scopes. On -> trigger is active. LED 1 is off) 3. Map LED 1 + 2 to channel 3 + 4 LED --------------------------------------- Use (hidden) Channel 3 + 4 LEDs as trigger indicator. LED 1 + 2 are not standard and have to be installed by own hardware modification. 4. Force Trigger ------------------------------------ Single trigger setup. Choose behaviour of single button - off (no manual trigger function - standard behaviour) - double push (first push activates single mode, second push always initiates a manual trigger) - direct (forces a manual trigger in run mode immediately without changing to single mode. There is no function in single mode) 5. Pre Trigger Setup ------------------------------------ Choose behaviour of Pre Trigger at TB change and Auto Pre Trigger. - Left Edge (Auto Pre Trigger set to the left grid edge, grid position keeps constant at TB change) - First Div (Auto Pre Trigger set to the first grid division on the left, grid position keeps constant at TB change) - Grid Middle (Auto Pre Trigger set to the grid middle, grid position keeps constant at TB change) - Trace middle (Auto Pre Trigger set to the trace middle, grid middle (memory window) follows, grid position keeps constant at TB change) - Keep (Auto Pre Trigger has no effect, pre trigger value keeps constant at TB change) - Keep + Follow (Auto Pre Trigger centers the grid (memory window) over the pre trigger position, pre trigger value keeps constant at TB change, memory window follows) 6. Trigger Level Setup ------------------------------------ - Fix Position: When switching the voltage range the trigger level will keep the same position in the grid. That results in a scaling triggerlevel which changes with every voltage range. - Constant The trigger level is constant in every voltage range. That results in a changing grid position. When grid limit is reached the position will not change anymore. Turning the triggerlevel wheel will adjust the level to the new voltage range, ************************************************* * Hardwaresettings * ************************************************* 1. ADC Setup ------------------------------------ - The factory setting results in a resonance problem at higher frequencies on some devices. - The HF-setting deactivates some internal filters in the readout logic of the FPGA. This should make you able to measure frequencies up to 150 MHz and more without ringing. HF settings may cause some distortions on the signal in certain cases, for that it is recommended to use the factory setting if you are measuring below 20 MHz. Try out! - Test 1 - 4 -> n.a. A few Users had some problems with spikes, so there are some other test settings to find out which one matches best to Your device. -> deactivated now! 2. Pre Gain Setting ------------------------------------------- The Pre Gain menu allows you to choose the Factory setting of scaling and input circuits or settings for hardware modifications in the preamp stage on the mainbord. A simple modification to make the frequency response more linear and to optimize high frequency measuring is to exchange the preamp resistors 2 x 0 Ohm / 1 x 156 KOhm against 2 x 24.9 Ohm / 174 (180) Ohm. Due to that You can choose the 24.9 Ohm setting in this menu which fit to those modifications. As to read in the hardware thread http://www.mikrocontroller.net/topic/1661333#postform there is also a little preamp board available as a new input stage. For this modification I added the "Add On" entry. Also available now are further modifications depending on the existing OPA656 (LB-Mod) and OPA653 (OPA653 Mod). Infos can be found here: http://sourceforge.net/projects/welecw2000a/files/Hardware/Modifications/ 2. Gain Adjust ------------------------------------------- It is possible now to adjust the scaling by yourself. Use a reference voltage and adjust the voltage as you like. It is recommended to use minimum 2/3 range as reference. Default setting is gain 1.00 - adjstment range is between 0.5 - 2. 4. ADC Driver Setup ------------------------------------------- Here You can choose between different driver implementations. Standard is a very stable working C-coded driver. Recommended because faster is the assembler driver. They are working very stable and very fast. The "quick and dirty" driver without byte overflow protection is only for testing and therefor not choosable. ************************************************* * Utility * ************************************************* 1. Calibrate Offsets ------------------------------------ New calibration which calibrates ADC-offsets and DAC-offsets in one process. 2. Calibration Sets ------------------------------------ This function supports 4 different calibrations for external input divices with differing DC-offset like active probes or similar. For normal purposes "Standard" can be used. 3. Test Signal ------------------------------------ Generates internal Testsignals for every channel. This enables the possibility to test several DSO-functions without any real signal generator. The levels and frequencies of the signals may vary with voltage range and/or timebase. This functions can be tested with the test signal: - signal processing like noise filter, FFT, math, interpolation - main timebase settings - Run/Stop/Single - trigger LEDs - delayed TB - X-Y mode - cursor functions - Quick Measure - Save/Recall - memory browser - display settings - Hardware -> Gain - Quick Print (screenshot etc.) - channel dependent settings - voltage range - DC/AC/GND - invert - zerolevel - dispatch - center This functions can not be tested due to hardware near implementation: - autoscale - calibration - acquisition -> average - triggering - ultra slow TB - BW limit (in channel menu) - extended utility menu -> Delay ************************************************* * Math * ************************************************* 1. Offsets ------------------------------------ Gives the possibility to change the virtual zero of the math channel. Turning faster lets the offset snap in on the grid lines. Pushing the offset button once more resets the offset to zero. Offset can be adjusted for every math operation separately. ************************************************* * Hidden Functions * ************************************************* The hidden functions can be reached by using a serial terminal and special keys on the pc keyboard. - Shift + K Start frame counter and stop watch in background. Both are running continuous when started. - Shift + L read actual frame counter and get elapsed time from stop watch. Calculate frames per second. This can be done several times after another. Longer measuring times will give a more precise result. To reset counter and stop watch use Shift + K again. --------------------------------------------------------------------------------------------------- - Shift + O Renaming function to change the model label for modified devices. Depending on the hardware settings (hardware menu -> Gain) the label will be changed and written into the protected flash. This label has no influence to the hardware functions. It is only for display. Gain Label ----------------------------------------- Factory W20xxA (no change) LB-Mod W202xA / OPA656 Mod OPA653 W203xA / OPA653 Mod 24.5Ohm W202xA (W2022A or W2024A) Add On W203xA / LMH6518 Mod - Shift + P Change model label to 100MHz model (W2012A or W2014A) !!!To set back the complete model string, set the gain to "24.5Ohm" and use the hidden function Shift + O. Now your label displays a normal 200MHz model. If you have a 100Mhz device use the hidden function Shift + P after that. (also possible "Factory" -> Shift + O -> Shift + P = W2012A/W2014A) ----------------------------------------------------------------------------------------------------- - Shift + F Show flash ID and a description of the meaning. ----------------------------------------------------------------------------------------------------- - Shift + N Generate trigonometric functions and write them to the flash. This is done automatically by the startup routine one time. After successful writing this won't be done anymore. This hidden function starts a new generation and writing of the tables. ----------------------------------------------------------------------------------------------------- Regards Hayo