Stimulus Generator 4002 Manual
Information in this document is subject to change without notice. No part of this document may be reproduced or transmitted without the express written permission of Multi Channel Systems MCS GmbH. While every precaution has been taken in the preparation of this document, the publisher and the author assume no responsibility for errors or omissions, or for damages resulting from the use of information contained in this document or from the use of programs and source code that may accompany it.
Table of Contents 1 1.1 1.2 1.3 Introduction About this Manual Terms of Use for MC_Stimulus II Limitation of Liability 1 1 1 1 2 2.1 2.2 2.3 Important Information and Instructions Operator's Obligations Guarantee and Liability Important Safety Advice 3 3 3 4 3 3.1 3.2 3.3 3.4 First Use of the Stimulus Generator Welcome to the STG and MC_Stimulus Setting Up and Connecting the STG Driver Installation Installing the Software 5 5 7 8 8 4 4.1 4.
Stimulus Generator 4002 Manual iv 8 8.1 Downloading Stimuli Downloading Stimulus Files 8.1.1 Download Modes 8.1.2 Independent Channel Download 47 47 48 48 9 9.1 9.2 9.3 9.4 9.5 9.6 General Software Features Customizing the Main Window Menu Bar Toolbar Shortcut Keys File Menu Settings Menu 51 51 51 52 53 53 54 10 10.1 10.2 10.3 10.4 10.5 Synchronizing Events Digital Output Signals (Sync Out) Triggering Stimulation (Trigger In) Trigger Settings Multi File Mode Batch Mode 55 55 56 58 62 64 11 11.
1 Introduction 1.1 About this Manual This manual comprises all important information about the installation and operation of the stimulus generator STG4000 series and MC_Stimulus II software. It is assumed that you have already a basic understanding of technical and software terms. No special skills are required to read this manual. This documentation refers only to the STG hardware and MC_Stimulus II software.
2 Important Information and Instructions 2.
Stimulus Generator 4002 Manual 2.3 Important Safety Advice Warning: Make sure to read the following advice prior to install or to use the device and the software. If you do not fulfill all requirements stated below, this may lead to malfunctions or breakage of connected hardware, or even fatal injuries. Warning: Obey always the rules of local regulations and laws. Only qualified personnel should be allowed to perform laboratory work.
3 First Use of the Stimulus Generator 3.1 Welcome to the STG and MC_Stimulus Product line overview Stimulus generators of the 4000 series are general purpose stimulators designed for a wide variety of applications, both in vitro and in vivo. Flexible and easy-to-use MC_Stimulus software enables complex stimulus waveforms (both current and voltage).
Stimulus Generator 4002 Manual Custom applications for the Download or the Streaming mode can be programmed in Matlab, Labview, C/C++, and Visual Basic. This documentation refers only to the STG hardware and MC_Stimulus II software. For more information on the STG's DLL functions and programming of custom software, please read the separate documentation of the Documentation folder in the MC_Stimulus II program directory.
First Use og the Stimulus Generator 3.2 Setting Up and Connecting the STG Note: You can use a USB hub for connecting the STG to the computer, for example, if you have no free USB port or if you need to extend the USB cable.
Stimulus Generator 4002 Manual 3.3 Driver Installation The stimulus generator is a plug and play device. The driver is automatically installed together with the MC_Stimulus II program. The Microsoft Windows ® operating system detects a new hardware when the stimulus generator is connected to the computer, if the program has not been installed beforehand. Simply cancel the driver installation and proceed with the installation of the MC_Stimulus II program.
4 Operating the STG 4.1 Operation Overview Warning: Make sure that you do not come in contact with the cables or the connectors of the STG after you have started the STG. The high voltage and power can lead to injuries. Warning: Do not start the STG if you are unsure about the channel configuration or the nature of the downloaded file. 1. Set up your experiment. 2. Switch the STG on. Note: It is recommended to start the STG ten minutes before use to allow warming up! 1.
Stimulus Generator 4002 Manual STG interface: You can start the stimulation by pressing the Start / Stop button on the front panel of the STG. Press the button again to stop the stimulation. Starting the STG by pressing the Start / Stop button is considered as activating all trigger inputs, that is, all channels are started and stopped, and all Sync Out outputs are active when the STG is started.
Programming Stimulus Protocols STG and Stimulus Protocol Information: Autocalibration During the first ten minutes after starting the STG, the device emits every minute high frequency signals (small bursts) for internal offset calibration of the current outputs in a range of +/- 10 mV. After warming up the STG, the calibration signals later will be delivered half-hourly.
Stimulus Generator 4002 Manual 4.2 Operating Multiple STGs If you have more than one STG connected to the same computer, please click under "STG" in main menu "Select Device". In the "Select Device" dialog you can choose which STG you like to control from the currently active MC_Stimulus II program. The serial number is printed on the STG's case. The serial number of the currently active STG is displayed on the status bar of the currently active instance of the MC_Stimulus II program.
Programming Stimulus Protocols 5 Programming Stimulus Protocols 5.1 MC_Stimulus II Sample Files for STG 4000 Series These sample files are intended for demonstrating basic features of the Stimulus Generator 4002, for basic applications with the MEA System. If you are using a MEA-System, please see also the MC_Rack tutorial in the MC_Rack help or the separate PDF on the installation volume. The sample files are automatically installed to the Examples folder in the MC_Stimulus II program directory.
Stimulus Generator 4002 Manual monophasic_voltage_1V_100μs.stm Stimulus type: Monophasic test pulse Amplitude: 1 V Duration: 100 µs Inter-Stimulus-Interval: 24 ms biphasic_voltage_1V_100μs.stm Stimulus type: Biphasic test pulse Amplitude: 1 V Duration: 100 µs per phase Inter-Stimulus-Interval: 24 ms ASCII-Import-Biopotential.stm This file is not intended for a real experiment, but demonstrates the ASCII import feature.
Programming Stimulus Protocols 5.4 MC_Stimulus II Worksheet You can freely combine any pulse types. Use a separate row for each pulse type. Hint: Several tools are provided for editing whole columns at once or autocreating entries. 1. Select the desired output type first. Click either Voltage or Current under Output Mode on the file window of MC_Stimulus. 2. Click a tab to select an output channel. The according channel worksheet is brought to front. 3. Now you can enter the pulses into the worksheet.
Stimulus Generator 4002 Manual 5.5 Pulse Types Three basic pulse types are available in MC_Stimulus II. You can create virtually any pulse by combining different types: Rectangular Ramp Sine wave Note: The time resolution is 20 μs. When you enter time steps that are not a multiple of 20 μs, the length of the step is internally adjusted (rounded arithmetically, that is, 249 μs would be rounded down to 240 μs, 250 would be rounded up to 260 μs) to a valid value.
Programming Stimulus Protocols Enter each voltage / current level and the duration of the pulse. The voltage / current jumps directly to the specified level. In one row, you can enter up to three voltage / current levels. Use the next row for programming more levels. Ramp pulse type Define the starting point, end point, and the length of the ramp. The ramp is then build according to these parameters in small single steps of 20 μs.
Stimulus Generator 4002 Manual 5.6 Define the amplitude and the period of the sine wave. The sine wave is then computed according to these parameters with a minimum resolution of 1 mV and 20 μs. If you enter a negative amplitude, the sine wave starts with its negative alternation. Autorepeating Pulses and Protocols For entering complex stimuli easier and faster, you can repeat rows and groups instead of entering the pulses several times into the worksheet. You can repeat each single row.
Programming Stimulus Protocols 1. Select several cells by clicking and dragging cells in the Group Repeat column. Selected cells are highlighted in black. 2. Point to the selected cells and right-click to open the context menu. 3. Click Group / Ungroup. The corresponding rows are grouped now. This is indicated by a merging of the Group Repeat cells. 4. Type the number of repeats into the merged Group Repeat cell.
Stimulus Generator 4002 Manual In the following example, the stimuli on output channels 1 and 2 triggered by Trigger 1 are repeated three times after the trigger event, each time accompanied by the Sync Out 1 output. All other stimuli are applied once after their respective trigger event. Repeating complete pulse protocols, Gating Trigger Repeated stimulation of complete protocols can also be controlled by a gating trigger.
Programming Stimulus Protocols 5.7 Autocreating Entries and Editing Columns Changing time units for a complete column 1. Click any Unit column header to select a column. The selected column is highlighted in black. 2. Right-click and click Change Time Unit. 3. Select the desired time unit. All units in the column are set to the selected time unit.
Stimulus Generator 4002 Manual Inverting pulses in a column 1. Click any Value column header to select a column. The selected column is highlighted in black. 2. Right-click and click Invert Selection. The polarity of the signals is switched from positive to negative and vice versa.
Programming Stimulus Protocols Incrementing columns This feature is very convenient for setting up long and complex stimuli without entering each value manually. You can enter and edit multiple voltage values or time lengths. You can keep all zero values unchanged with the option Keep Zero. Apart from an absolute shift or increment factor, you can modify values by the percentage as well.
Stimulus Generator 4002 Manual All values in the selected column are modified by the selected factor. In the example, 100 is added to all values, resulting in a total of 100 because the initial value has been 0. Creating time or voltage / current increments With this option, you enter a base value for modification of all values in the selected column. The first row is modified by the base value. The second row is modified by the double value, the third row by thrice the base value, and so on.
Programming Stimulus Protocols The value in the first row is incremented by the selected start value of 10. The next value is modified by the double value (20), and so on. You can now fill further columns in the same way. Thus, you can easily set up a stimulus with incremented pulse lengths like this with only a few mouse-clicks.
Stimulus Generator 4002 Manual In the same way, you can set up a stimulus with voltage / current increments. Shifting absolute time or voltage values With this option, the signs of the selected values are ignored. Zeros are never changed, that is, the option Keep Zero cannot be deselected. 1. Under Type of Increment, select Absolute Value. 2. Enter the desired shift factor.
Programming Stimulus Protocols The absolute values of 200 and 200 are both 200. This absolute value of 200 is modified by the shift factor of 50, resulting in 250. The negative value is now 250, and the positive value is 250. (If you had chosen the option Shift instead, the computed result would have been 200 + 50 = 150.) All zero values are not changed. Autocreating entries You can use the Autofill feature to set up advanced time or voltage/current increments.
Stimulus Generator 4002 Manual 3. Select one out of three commands and fill in the white text boxes. The column is filled according to the specifications.
Programming Stimulus Protocols 5.8 Auto Sync for Autocreating Trigger Pulses If you want to synchronize other devices, for example, a MEA1060-BC amplifier, the MC_Card or an USB data acquisition device with the stimulus generator, you have to set up the digital output of the Sync Out channels in synchrony to the stimulus pulses. This may sometimes be a bit tricky and time consuming, especially for complex stimulus protocols.
Stimulus Generator 4002 Manual 4. On the Settings menu, click Auto Sync to enable the Auto Sync feature. The Sync Out protocols will be autocreated in synchrony with the pulse protocols on the assigned channels, will show up in the WYSIWYG window immediately, and will be downloaded onto the STG with your next download. (Please make sure that the display and download options are appropriate, that is, all necessary Sync Out channels are selected.
Programming Stimulus Protocols 5.9 Adjusting the Stimulus Intensity Level After having programmed the stimulus protocol, you can either download the protocol "as is", or you can adjust the stimulus intensity level, that is, choose a percentage (from 0 to 200 percent) of the programmed amplitudes, independently for both channels.
6 ASCII Import / Export 6.1 Loading Files The ASCII import filter is used to load stimulus protocols from an ASCII file into the stimulus worksheet of MC_Stimulus II. You can use this feature for feeding recorded signals (for example, exported from MC_Rack, see the MC_Rack manual) into the stimulus generator. You can also export the data from MC_Stimulus, modify it with your custom text or spreadsheet editor, and reimport it into MC_Stimulus II. The current version of the import filter is version 3.1.
Stimulus Generator 4002 Manual 6.2 Exporting Files 1. On the File menu, click Export ASCII File. The Save As dialog box appears. 2. Browse to the target folder and enter a file name. 3. Click Save to generate the ASCII file. All pulse protocols from the active file will be saved in ASCII file format. The MC_Stimulus II ASCII format type is format type 4. For your convenience, the generated ASCII file includes the header that is required for reimporting the file into MC_Stimulus II. 6.
ASCII Import / Export Example: You have to include the following line in the ASCII file if you have installed MC_Stimulus II for STG4002. channels: 2 Output mode is either voltage or current. Example: output mode: voltage Six different format types are available: 1, 2, 3, 4, 5, 6. Example: format: 3 Data Preceding the data, the output channel number has to be specified by the following line.
Stimulus Generator 4002 Manual Format type 3 This format type is available only in the current version of the import filter. It allows you to use a third column of Value and Time. value time value time value time repeat Example: The following picture shows an ASCII stimulus file opened in a standard spreadsheet program.
ASCII Import / Export The same file would look like this in a standard text editor program. You can see the tabs, spaces, and CR / LF. After loading the file into the MC_Stimulus II worksheet, you can edit and download the file as usual. Format type 4 This format type is available only in the current version of the import filter. It is the plainest format with only one column for the voltage / current values and one column for the time lengths.
Stimulus Generator 4002 Manual Format type 5 This format type is available only in the current version of the import filter. It allows you to use ramp and sine waveforms as well as rectangular waveforms. You specify the Pulse type in the first column, and the waveform in the three following columns. The general rules for setting up ramp and sine waveforms fully apply (see also Pulse Types). The pulse types are defined by the following numbers: Rectangular = 0, ramp = 1, sine = 2.
ASCII Import / Export After loading the file into the MC_Stimulus II worksheet, you can edit and download the file as usual. Format type 6 Note: This file format is used by MC_Rack ASCII export! This format type is available only in the current version of the import filter. This is a basic format with two columns: The absolute time in seconds, and the absolute value of voltage in microvolts (μV) or current in microamper (μA). This file format is used by MC_Rack ASCII export.
Stimulus Generator 4002 Manual The following picture shows a file of format type 6 with header. Using the format type 6 without header, only the first channel of the MC_Rack raw data file can be imported. Using the format type 6 with header you choose how many channels are imported in "channels", line 3. The output mode in line 4 has to be voltage. You choose which channel should be imported first in "channels" line 6. You can add the channels you also want to import one after the other in any order.
ASCII Import / Export ASCII Import of Files For ASCII import of files, please use the command ASCII Import in main menu "Settings". The dialog "ASCII Import Settings" will open. Settings for ASCII import files without header: Select the format type from one to six from the drop down menu "Format". Select the number of the row from which the file should be imported. Row numbers are available from one to ten from the drop down menu "From row". Select the "Output Mode" in the check boxes: Voltage or Current.
7 Stimulus Display 7.1 Selecting Channels To enlarge the display size of the channels, we suggest that you show only those channels you are currently working with. Note: This will affect only the display. It has no effect on the download of signals. To select or deselect channels for downloading, click the Download Channel (or Download Sync) check boxes in the main window of the program. Clear the check box of all channels that are not in use.
Stimulus Generator 4002 Manual 7.3 Display Tools Several tools are provided to optimize the graphical presentation of the stimuli. If you later choose to display channels, the axes of the new displays are set to the default values. The time axis can display only positive values. The y-axis of the Sync Out channels cannot be adjusted, because only values of 0 and 1 are available for these channels. Enable scrolling Scroll the axes by clicking and dragging with your mouse.
Stimulus Display Zooming the display 1. Click to enable the scaling. 2. 2. Click the axis you like to scale. The mouse pointer becomes an arrow. 3. While holding down the mouse button, move the mouse up / right to zoom the axis in, and move the mouse down / left to zoom the axis out. - OR You can use the keyboard: Press LEFT ARROW or DOWN ARROW to zoom the axis out, RIGHT ARROW or UP ARROW to zoom the axis in.
8 Downloading Stimuli 8.1 Downloading Stimulus Files After having set up the stimulus file, you can download the file to the connected STG. You can select the channels that you want to download or download the complete file. You can start the stimulation directly after the download, or start it manually with the software or hardware controls, or start it on a trigger. See also chapter "Operating the STG" for more information. Warning: Check the file thoroughly before downloading it on the STG.
Stimulus Generator 4002 Manual 8.1.1 Download Modes Default Mode When downloading files created in MC_Stimulus II software to a stimulus generator of the STG4000 series, two different download modes are available. In "Default Mode", for each download all channels are stopped and cleared before the new paradigm is downloaded. All available channels are downloaded one after the other regardless of the space each channel needs, which means that the available memory is optimally used.
Downloading Stimuli If the independent download option is active, a click on the "Download" or" Download and Start" button will only download a new paradigm to the channels selected in the "Download Channel" check box (1 and 6 in this example). Other channels will not be influenced. However, the individual download option is influenced by the "Trigger Settings". To be able to download channels independently from each other, it is mandatory that these channels are assigned to different triggers.
9 General Software Features 9.1 Customizing the Main Window You can customize the size and position of open file windows and the toolbar in MC_Stimulus II. You can hide the toolbar and the status bar by deselecting them on the View menu. You can arrange the windows with the commands on the Window menu. Cascade: Use this command to arrange multiple opened windows in an overlapped fashion. The windows are resized to the standard size.
Stimulus Generator 4002 Manual 9.3 Toolbar For your convenience, you will find some of the more commonly used commands as a button on the toolbar. 52 New File Creates a new MC_Stimulus II file (*.stm) file. Open File Opens a previously saved MC_Stimulus II file (*.stm) file. Save File Saves a MC_Stimulus II *.stm file to the chosen destination. Cut Row Deletes selected row(s) and sends deleted row(s) to clipboard. Copy Row Sends selected row(s) to clipboard.
General Software Features 9.4 Shortcut Keys Shortcut keys offer you another way to accomplish common tasks. Using a shortcut key usually consists of pressing and holding one key while pressing a second key. See the list of shortcut keys available in the software.
Stimulus Generator 4002 Manual Save as Use this command to save your file under a new name, for example, if you like to use a file as a template for a new file. 1. On the File menu, click Save As. 2. Browse your folders and enter a file name. 3. Click Save. The current worksheet is now saved under the new name. You may open the file using MC_Stimulus II later on to continue your experiment. Import ASCII File Please see the chapter " ASCII Import / Export".
10 Synchronizing Events 10.1 Digital Output Signals (Sync Out) The output of the digital Sync Out outputs is a 3.3 V TTL signal. A logic state of 1 means 3.3 V, and a logic state of 0 means 0 V. Please note that the digital output is about 15 μs faster than the analog output. This small offset is generally sufficient to make sure that the Sync Out signal precedes the stimulation, which is important for synchronizing events.
Stimulus Generator 4002 Manual The following example shows a blanking signal (programmed with MC_Stimulus II) of 300 μs length for a biphasic pulse of 200 μs length. See also the “MEA_Select Help or the MEA Amplifier with Blanking Circuit” manual for more information. You can use the Auto Sync feature for autocreating the Sync Out pulses without entering values manually. Please see "Auto Sync for Autocreating Synchronous Sync Out Pulses". 10.
Synchronizing Events You can start and stop the trigger manually at any time using the LED Start / Stop buttons. Custom switch for "remote-controlling" of the STG You can connect any device that produces TTL outputs to the Trigger In connector of the STG, for example a switch. For example, you can use a trigger for remote controlling the STG if it is not within reach during an experiment.
Stimulus Generator 4002 Manual 10.3 Trigger Settings Triggering output channels (Standard mode) In the preceding example, trigger input 1 is used to trigger the output channel 1 and 2. This means, each time a TTL pulse is applied to Trigger In 1, stimulation on channels 1 and 2 is started simultaneously. The complete protocols of these two channels would be executed five times after the trigger event, if continuous mode would be off.
Synchronizing Events Triggered action when channel(s) still active You can define what action should be taken when any of the channels assigned to the trigger are still active. Please click the expand button to show the advanced options: Stop: A following trigger input stops the stimulation on the assigned channels if at least one channel that has been assigned to this particular trigger is still active in the moment of the trigger event.
Stimulus Generator 4002 Manual Single Trigger Important: This feature is available only with STG 4000 series. The MC_Stimulus II version 3.2.3 (or later) with firmware update must be installed. Additional to the general trigger states “running” and “stopped” each trigger can now be set up in a new state, called “armed”. That means, the trigger is ready to start the stimulus protocol, but waiting for an external signal from the rear panel trigger inputs to execute the stimulus protocol one time only.
Synchronizing Events Sweep Count The number of sweeps are counted and displayed for each of the triggers at the bottom of the main window. Please note that not the number of stimuli but the number of sweeps is counted, whereby one sweep is defined as one complete run of the programmed stimulation pattern, as displayed in the main window. So, if five stimuli are programmed, and the repeat rate in the Trigger Setting menu is set to six, 30 stimuli will be delivered but the sweep count will be six.
Stimulus Generator 4002 Manual 10.4 Multi File Mode As an alternative to triggering separate channels in a single stimulus protocol, you can also trigger up to two separate stimulus files in the Multi-File mode. This feature allows you to trigger different stimulus protocols on overlapping channels. For example, you can control stimulus pattern A by trigger 1 on channels 1 and 2, and stimulus pattern B by trigger 2 on channels 2.
Synchronizing Events 8. Check all stimulus protocols before download. Please make sure that you have selected all necessary channels under Download Channel for each file separately. 9. Download the files onto the STG by clicking Download on the STG menu. 10. The stimulation as specified in the selected MC_Stimulus files will now be triggered by the selected trigger inputs.
Stimulus Generator 4002 Manual 10.5 Batch Mode You can download and run several stimulus files one after the other in the Batch mode. The first file in the list is downloaded and started directly after the download, or started manually with the software or hardware controls, or started on a trigger. After the first file has been run, the second file in the list is downloaded, and so on.
Synchronizing Events Operating the STG in Batch mode Important: You can operate the STG in Batch mode only with a valid computer connection. A file in the batch list is only downloaded after the preceding file has been run. 1. On the Batch menu, click Open to open a batch file. The Open dialog box appears. 2. Browse your folders and select a valid batch file, for example the sample file TetanusBatch.stb in the MC_Stimulus II program folder. 3. The Batch Status Display opens.
11 Analog Output Signals 11.1 Output Modes The stimulus generator operates in voltage and current mode. Choose voltage or current mode in the main window of MC_Stimulus II. Please make sure that you use the appropriate stimulation mode for your experiment. The difference between current and voltage controlled stimulation is described in the following. In voltage mode, the voltage level is held constant and the current output depends on the electrode resistance.
Stimulus Generator 4002 Manual 11.2 Voltage Mode If you want to operate the STG in voltage mode, you have to select "Voltage" in Output Mode of the main window of MC_Stimulus II. You will usually use the + and GND outputs. The output signal is identical with the programmed signal in the normal ranges of the electronics' accuracy. See illustration "Voltage mode: Standard Setup". The output signals are inverted (multiplied by -1) if you use the - outputs.
Analog Output Signals STG output signals: -U to GND STG output signals: +U to -U 69
Stimulus Generator 4002 Manual Screen shot from a standard oscilloscope triggered on the Sync Out pulse (Please see "Measuring output signals with an oscilloscope"). Green trace = voltage output (+U), red trace = inverted voltage output (-U), pink trace = TTL output from the Sync Out. Voltage output 1 V and Sync Out.
Analog Output Signals 71
Stimulus Generator 4002 Manual 11.3 Current Mode If you want to operate the STG in current mode, you have to select "Current" in Output Mode of the main window of MC_Stimulus II. You will usually use the + and GND outputs. See illustration "Standard setup". The output signals are inverted (multiplied by -1) if you use the - outputs. If the load resistance, that is, the electrode impedance is very high, the output voltage can get very high, too.
Analog Output Signals Screen shot from a standard oscilloscope triggered on the Sync Out pulse (Please see "Measuring output signals with an oscilloscope"). Green trace = current output (+I), red trace = inverted current output (I), pink trace = TTL output from the Sync Out. Current output 200 μA and Sync Out. The time lag between the Sync Out output and the current output is approximately 15 μs (+/- 2 μs) if continuous mode is enabled and 50 μs (+/- 2 μs) if continuous mode is disabled.
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Analog Output Signals 11.4 Measuring Output Signals with an Oscilloscope For test purposes, you can measure the output signals with an oscilloscope. Please see the appendix for the pin layout of the sockets on the front panel of the STG 4000 series. Most standard oscilloscopes have a probe with a ground cable. This probe is usually connected to the oscilloscope via a BNC socket.
Stimulus Generator 4002 Manual 11.5 Rise Time The rise time of the voltage output is constant and independent from the stimulus protocol. The rise time of the current output is no fixed hardware property. The kinetics depend on the amplitude of the current pulse and the load resistance, that is, generally the electrode impedance. The resistance affects the kinetics much stronger than the amplitude. Generally, this does not make much difference for biological applications.
Analog Output Signals Resistance dependency of rise time The higher the load resistance, the higher will be the rise time. The rise time (10 % / 90 %) was measured with increasing load resistances and a constant current amplitude of 50 μA. For 50 μA pulses, the relationship is linear up to the maximum load resistance (Please see "Current Mode") as shown by the following curve.
Stimulus Generator 4002 Manual Example 1a: Voltage Mode: The green trace shows the voltage (+U) output; and the pink trace shows the TTL output from the Sync Out that was used for triggering the oscilloscope Rise time with programmed 500 mV and 50 μA pulses, 10 k load resistance.
Analog Output Signals Example 1b: Current Mode: The green trace shows the current output (+I) with a load resistance of 10 k; and the pink trace shows the TTL output from the Sync Out that was used for triggering the oscilloscope Rise time with programmed 500 mV and 50 μA pulses, 10 k load resistance. Rise time (10 % / 90 %) = 3 μs Result of Example 1: The rise time is about 3 μs for the 500 mV voltage pulse, and about 3 μs for the 50 μA current pulse.
Stimulus Generator 4002 Manual Example 2a: Voltage Mode: The green trace shows the voltage (+U) output; and the pink trace shows the TTL output from the Sync Out that was used for triggering the oscilloscope Rise time with programmed 5 V and 500 μA pulses, 10 k load resistance.
Analog Output Signals Example 2b: Current Mode: The green trace shows the current output (+I) with a load resistance of 10 k; and the pink trace shows the TTL output from the Sync Out that was used for triggering the oscilloscope Rise time with programmed 5 V and 500 μA pulses, 10 k load resistance. Rise time (10 % / 90 %) = 3 μs Result of Example 2: The kinetics and the rise time of the 5 V voltage pulse are comparable to the 500 mV pulse.
Stimulus Generator 4002 Manual Example 3a: Current Mode: The red trace shows the current output (+I) with a load resistance of 100 k; and the pink trace shows the TTL output from the Sync Out that was used for triggering the oscilloscope Rise time with programmed 5 V and 500 μA pulses, 100 k load resistance.
Analog Output Signals Example 3b: Current Mode: The green trace shows the current output (+I) with a load resistance of 1 M; and the pink trace shows the TTL output from the Sync Out that was used for triggering the oscilloscope Rise time with programmed 5 V and 500 μA pulses, 1 M load resistance. Rise time (10 % / 90 %) = 120 μs Result of Example 3: With a higher load resistance, the current pulse shows a different kinetic behavior: The rise time increases significantly (about 100 μs).
Stimulus Generator 4002 Manual 11.6 Comparison of Output Signals in Current Mode To show the different behaviour of the output signals in current mode, there are some examples to get an idea how the stimulus generator will deliver the stimulus pulses. The screen shots are from a standard oscilloscope triggered on the Sync Out pulse (see "Measuring output signals with an oscilloscope").
Analog Output Signals Example 1b: Current pulse with programmed 1600 μA for 20 μs and 20 μs interval and 10 k load resistance. The pulse is biphasic, and 1600 μA which is the limit of the maximum capacity of the STG 4002. Green trace = current output (+I), pink trace = TTL trigger output from the Sync Out. Result of Example 1: The current output signal is delivered unmodified without any influence of the length of the pulse with an amplitude of 1600 μA which is at the maximum capacity of the STG 4002.
Stimulus Generator 4002 Manual Example 2: Influence of the length of a current pulse 100 μs versus 20 μs with an amplitude of 16 μA which is a hundredth of the limit of the maximum capacity of the STG 4002 (constant amplitude and load resistance). Example 2a: Current pulse with programmed 16 μA for 100 μs and 20 μs interval and 10 k load resistance. The pulse is biphasic,16 μA Green trace = current output (+I), pink trace = TTL trigger output from the Sync Out.
Analog Output Signals Example 2b: Current pulse with programmed 16 μA for 20 μs and 20 μs interval and 10 k load resistance. The pulse is biphasic,16 μA. Green trace = current output (+I), pink trace = TTL trigger output from the Sync Out.
Stimulus Generator 4002 Manual Example 3: Influence of the length of a current pulse and a high load resistance. Current pulse with programmed 16 μA for 100 μs and 20 μs interval and 1 M load resistance. The load resistance is very high. Please keep in mind that the load resistance of 1 Mis parallel toM of the probe of the oscilloscope.
Analog Output Signals Example 4: Influence of the length of a current pulse and a high load resistance. Current pulse with programmed 50 μA for 1 ms and 1 ms interval and 1 M load resistance. The load resistance is very high, the duration of the pulse and the interval are long. Please keep in mind that the load resistance of 1 Mis parallel toMof the probe of the oscilloscope. That means, the load resistance is reduced to 900 konly The long pulse is biphasic, 50 μA.
Stimulus Generator 4002 Manual 11.7 Capacitive Behavior of Stimulation Electrodes Regarding the generally used stimulus pulses, stimulating electrodes behave as plate capacitors. They need some time to discharge themselves after stimulation. As a result, artifacts interfere with the recording, and electrodes deteriorate over time due to electrolysis.
12 Troubleshooting 12.1 About Troubleshooting Most problems occur seldom and only under specific circumstances. In most cases, it is only a minor problem that can be easily avoided or solved. If the problem persists, please contact your local retailer. The highly qualified staff will be glad to help you. Please inform your local retailer as well, if other problems that are not mentioned in this documentation occur, even if you have solved the problem on your own.
Stimulus Generator 4002 Manual 12.3 Error Messages This chapter explains error messages to you that may occur during normal operation. They do not present a reason to worry and can be easily avoided. General operation is displayed when you try to close a file in Multi-File mode. You cannot close files if you are in Multi-File mode (indicated on the MC_Stimulus status bar). Please leave the Multi-File mode by selecting Standard under Mode in the Trigger Settings dialog box before closing files.
Troubleshooting ASCII Import These error messages relate to a wrong file format. Please see chapter "Supported File Format" for more information. The named line contains an unexpected character. The channel number specification has to precede the data. The channel number either lacks or the specified number does not exist, for example number 13. Each data column must have a header (value, time, or repeat).
Stimulus Generator 4002 Manual 12.4 Signal terminated when using Trigger In If you use the Trigger In to start the STG and the stimulation protocol is terminated right after start, check the Trigger Settings. If the Use Trigger as Gate function is selected, a protocol will only be active as long as the Trigger is HIGH. If the Single Trigger function is selected, the STG is armed and waits for an external trigger to execute the stimulus protocol one time only. Switch to Stop, Restart or Ignore. 12.
Troubleshooting 12.7 Internal Calibration Signals The STG emits sometimes autonomous high frequency signals. Cause: During the first ten minutes after starting the STG, the device emits every minute high frequency signals (small bursts) for internal offset calibration of the current outputs in a range of +/- 10 mV. After warming up the STG, the calibration signals later will be delivered half-hourly. The calibration is interrupted during stimulation.
13 Appendix 13.1 Technical Specifications STG 4002 Operating temperature Storage temperature 10 °C to 50 °C 0 °C to 70 °C Dimensions (W x D x H) 235 x 170 x 60 mm Weight 1.2 kg Fuse internal, 3.15 A slow Supply voltage (external power supply) 100 - 240 VAC @ 47 to 63 Hz Number of analog output channels 2 Output voltage -8 V to +8V @ max. ± 20 mA Output voltage resolution 1 mV Rise time (10-90 %) voltage 1.
Stimulus Generator 4002 Manual Interface and connectors Sync Out for synchronization with following devices 2digital channels via coax cable Trigger In for synchronization with preceding devices 2 digital channels via coax cable Interface (connection to computer) USB 2.0 High Speed Download rate max. 480 Mb per second Software MC_Stimulus II Version 3.3.
14 Index 99
Stimulus Generator 4002 Manual 100
A About dialog 51 Adjusting Stimulus Intensity Level ....................31 Amplifier blanking .............................................55 connecting ...................................68, 72 Amplitude adjusting stimulus intensity level.....31 effects on rise time ...........................76 of sine wave ......................................16 Analog current output...................................72 input ....................................................7 voltage output .......................
Stimulus Generator 4002 Manual settings ..............................................43 zooming .............................................44 Downloading batch mode .......................................64 shortcut key .......................................53 stimulus files ......................................47 Driver installation...........................................8 Duration pulse ...................................................16 E Edit Auto Sync Settings ............................
Index pulses ................................................. 18 rows ................................................... 18 O Open ASCII files ...........................................33 file ......................................................52 files in Multi File mode .....................62 shortcut key .......................................53 stimulus files ......................................53 Oscilloscope comparing STG current signals ........84 measuring current signals ................
Stimulus Generator 4002 Manual Sine wave pulse type ..........................................16 Single Trigger 58 Size to fit 44 Software installation...........................................8 requirements .......................................8 Start channels on trigger ...........................58 files on trigger...................................62 shortcut key .......................................53 STG .......................................................9 Starting point of ramp .........
Index measuring output with an oscilloscope ............................................................75 output mode .........................15, 67, 68 resolution ..........................................16 W Window menu ................................................. 51 WYSIWYG window ..................... 43, 44 Z Zooming 44 Warning messages disabling ............................................
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