Multichannel Systems STG3008-FA User Manual

STG3008-FA 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. In no event shall the publisher and the author be liable for any loss of profit or any other commercial damage caused or alleged to have been caused directly or indirectly by this document.

Printed: 10. 01. 2012

Multi Channel Systems MCS GmbH

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72770 Reutlingen

Germany

Fon +49-71 21-90 92 5 - 0

Fax +49-71 21-90 92 5 -11

info@multichannelsystems.com

www.multichannelsystems.com

Microsoft and Windows are registered trademarks of Microsoft Corporation. Products that are referred to in this document may be either trademarks and/or registered trademarks of their respective holders and should be noted as such. The publisher and the author make no claim to these trademark.

Table of Contents

1 Introduction 1

1.1 About this Manual 1

2 Important Information and Instructions 3

2.1 Terms of Use for MC_Stimulus II 3

2.2 Limitation of Liability 3

2.3 Operator's Obligations 3

2.4 Guarantee and Liability 3

2.5 Important Safety Advice 4

3 First Use of the Stimulus Generator 5

3.1 Welcome to the STG3008-FA and MC_Stimulus II 5

3.2 Setting Up and Connecting the STG 7

3.3 Driver Installation 9

3.4 Installing the Software 9

4 Operating the STG 11

4.1 Operation Overview 11

4.2 Operating the Amplifier 13

4.3 Operating Multiple STGs 15

5 Programming Stimulus Protocols 17

5.1 MC_Stimulus II Worksheet 17

5.2 Pulse Types 18

5.3 Autorepeating Pulses and Protocols 20

5.4 Autocreating Entries and Editing Columns 23

5.5 Auto Sync for Autocreating Trigger Pulses 29

5.6 Adjusting the Stimulus Intensity Level 30

6 ASCII Import/Export 33

6.1 Loading Files 33

6.2 Exporting Files 34

6.3 Supported File Formats 34

7 Stimulus Display 43

7.1 Selecting Channels 43

7.2 Display Settings 43

7.3 Display Tools 44

8 Downloading Stimuli 47

8.1 Downloading Stimulus Files 47

iii

STG3008-FA Manual

General Software Features 49

9.1 Customizing the Main Window 49

9.2 Menu Bar 49

9.3 Toolbar 50

9.4 Shortcut Keys 50

9.5 File Menu 51

9.6 Settings Menu 52

10 Synchronizing Events 53

10.1 Digital Output Signals (Sync Out) 53

10.2 Triggering Stimulation (Trigger In) 53

10.3 Trigger Settings 55

10.4 Batch Mode 57

11 Analog Output Signals 59

11.1 Output Modes 59

11.2 Voltage Mode 60

11.3 Current Mode 62

11.4 Rise Time 63

11.5 Comparison of Output Signals in Current Mode 71

11.6 Capacitive Behavior of Stimulation Electrodes 77

12 Troubleshooting 79

12.1 About Troubleshooting 79

12.2 Technical Support 79

12.3 Error Messages 80

12.4 Signal terminated when using Trigger In 82

12.5 Signal is not Repeated / Pulse Train Fails 82

12.6 Strong Peak Artifacts 83

13 Appendix 84

13.1 Technical Specifications STG3008-FA 84

13.2 Pin Layout 86

13.3 Contact Information 87

14 Index 89

1 Introduction

1.1 About this Manual

This manual comprises all important information about the installation and operation of the stimulus generator STG3000 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. For more information on the STG's DLL functions and programming of custom programs, please read the separate documentation in the documentation folder in the MC_Stimulus II program directory.

If you are using the STG for the first time, please read the important safety advice before installing the hardware and software (see Important Safety Advice, where you will find important information about the installation and first steps).

The printed manual and help are basically the same, so it is up to you which one you will use. The help offers you the advantage of scrolling through the text in a non-linear fashion, picking up all information you need, especially if you use the index and the search function. If you are going to read larger text passages, however, you may prefer the printed manual.

The device and the software are part of an ongoing developmental process. Please understand that the provided documentation is not always up to date. Check also the MCS web site (www.multichannelsystems.com) from time to time for downloading up-to-date manuals and new software versions.

2 Important Information and Instructions

2.1 Terms of Use for MC_Stimulus II

You are free to use MC_Stimulus II for its intended purpose. You agree that you will not decompile, reverse engineer, or otherwise attempt to discover the source code of the software.

2.2 Limitation of Liability

Multi Channel Systems MCS GmbH makes no guarantee as to the accuracy of any and all tests and data generated by the use the MC_Stimulus II software. It is up to the user to use good laboratory practice to establish the validity of his findings.

To the maximum extent permitted by applicable law, in no event shall Multi Channel Systems MCS GmbH or its suppliers be liable for any special, incidental, indirect, or consequential damages whatsoever (including, without limitation, injuries, damages for data loss, loss of business profits, business interruption, loss of business information, or any other pecuniary loss) arising out of the use of or inability to use MC_Stimulus II or the provision of or failure to provide Support Services, even if Multi Channel Systems MCS GmbH has been advised of the possibility of such damages.

2.3 Operator's Obligations

The operator is obliged to allow only persons to work on the device, who

 are familiar with the safety at work and accident prevention regulations and have been

instructed how to use the device;

 are professionally qualified or have specialist knowledge and training and have received

instruction in the use of the device;

 have read and understood the chapter on safety and the warning instructions in this manual

and confirmed this with their signature.

It must be monitored at regular intervals that the operating personnel are working safely.

Personnel still undergoing training may only work on the device under the supervision of an experienced person.

2.4 Guarantee and Liability

The General conditions of sale and delivery of Multi Channel Systems MCS GmbH always apply. The operator will receive these no later than on conclusion of the contract.

Multi Channel Systems MCS GmbH makes no guarantee as to the accuracy of any and all tests and data generated by the use of the device or the software. It is up to the user to use good laboratory practice to establish the validity of his findings.

Guarantee and liability claims in the event of injury or material damage are excluded when they are the result of one of the following.

 Improper use of the device.

 Improper installation, commissioning, operation or maintenance of the device.

 Operating the device when the safety and protective devices are defective and/or inoperable.

 Non-observance of the instructions in the manual with regard to transport, storage, installation,

commissioning, operation or maintenance of the device.

 Unauthorized structural alterations to the device.

STG3008-FA Manual

 Unauthorized modifications to the system settings.

 Inadequate monitoring of device components subject to wear.

 Improperly executed and unauthorized repairs.

 Unauthorized opening of the device or its components.

 Catastrophic events due to the effect of foreign bodies or acts of God.

2.5 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. Work according to good laboratory practice to obtain best results and to minimize risks.

The product has been built to the state of the art and in accordance with recognized safety engineering rules. The device may only

 be used for its intended purpose;

 be used when in a perfect condition.

 Improper use could lead to serious, even fatal injuries to the user or third parties and damage

to the device itself or other material damage.

Warning: The device and the software are not intended for medical uses and must not be used on humans.

Malfunctions which could impair safety should be rectified immediately.

High Voltage

Electrical cords must be properly laid and installed. The length and quality of the cords must be in accordance with local provisions.

Only qualified technicians may work on the electrical system. It is essential that the accident prevention regulations and those of the employers' liability associations are observed.

 Each time before starting up, make sure that the mains supply agrees with the specifications

of the product.

 Check the power cord for damage each time the site is changed. Damaged power cords should

be replaced immediately and may never be reused.

 Check the leads for damage. Damaged leads should be replaced immediately and may never

be reused.

 Do not try to insert anything sharp or metallic into the vents or the case.

 Liquids may cause short circuits or other damage. Keep the device and the power cords always

dry. Do not handle it with wet hands.

Requirements for the installation

 Make sure that the device is not exposed to direct sunlight. Do not place anything on top of the

device, and do not place it on top of another heat producing device. Otherwise, the device may overheat.

3 First Use of the Stimulus Generator

3.1 Welcome to the STG3008-FA and MC_Stimulus II

Product Line Overview

Stimulus generator of the 3000 series are general purpose stimulators designed for a wide variety of applications, both in vitro and in vivo. The STG3008-FA is a special version for use with cardiovascular catheter microelectrodes for animals.

The STG is additionally equipped with a filter amplifier FA and has the advantage that the device can be used for both, for stimulation and for recording. You switch software controlled between the two operation modes recording and stimulation.

The filter amplifier of the STG3008-FA provides four different gain factors 100, 200, 500, or 1000 and has a band pass filter with a bandwidth of 1 Hz to 2,2 kHz.

The stimulus generator STG3008-FA is available for simultaneous stimulation on up to eight completely independent stimulation channels. Each channel is freely programmable, combination of channels to achieve complex stimulation patterns is not necessary.

Flexible and easy-to-use MC_Stimulus II software enables complex stimulus waveforms (both current and voltage) in Download mode and Streaming mode. Waveforms designed in the program or imported from an external ASCII file are converted into pulses, which are sent to the stimulation electrodes.

Note: Please note that not all software features of MC_Stimulus II are supported by the hardware.

A trigger input and a Sync output for TTL signals allows to synchronize the stimulus generator with other instruments. Triggering of other devices via programmable TTL pulses (Sync Out) is possible, as well as triggering of the STG by external devices via the Trigger In input. For example, you can synchronize stimulation and recording with a TTL signal sent from the Sync Out output of the STG to the data acquisition system, for example, the MC_Card or an USB based data acquisition system.

The real-time stimulus generator STG3008-FA has two operating modes: Download mode and Streaming mode.

In Download mode, you can control the STG either by the MC_Stimulus II or by a custom program. Stimulus protocols are created in MC_Stimulus II or the custom program; complete protocols are downloaded onto the STG, and can after the download be executed without a computer connection.

STG3008-FA Manual

In the Streaming mode, you can control the STG either by the Stimulus Streamer or by a custom program. If you use the Stimulus Streamer, you can load stimulus protocols in Mono-MP3 or binary file format of unlimited size that were generated by a custom application and are then sent continuously from the computer to the STG in small data packets. If you use a custom program for controlling the STG, this program can generate and send the stimulation protocols in parallel from the computer to the STG.

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.

MC_Stimulus II

Stimuli are created user-friendly by entering the desired pulses (rectangular, ramp, or sine waveforms) into a worksheet. Waveforms can be combined freely to create virtually any stimulus pattern.

For even more convenience, repetitive stimulus patterns do not have to be entered separately, but can be grouped and looped. You can also import waveforms in ASCII file format and use them for stimulation. You can print and save stimuli and comments for later use and documentation of your experiments.

Created stimuli are displayed in a WYSIWYG stimulus display. All channels are set up separately.

First Use of the Stimulus Generator

3.2 Setting Up and Connecting the STG

Note: You can use an 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. Do not use a hub in Streaming mode! Please note that if you want to use the STG in Streaming mode, you cannot connect a second device that sends or receives continuous data streams, for example a web cam or USB speakers, to the same USB port, because the STG needs a broad bandwidth for the data transmission. This does not matter if you want to use the Download mode (via MC_Stimulus II or custom program) only.

Provide a power supply and a computer with USB port in the immediate vicinity of the installation site. Make sure the STG is switched off before you connect it to the power supply.

1. Place the STG on a stable surface, where the air can circulate freely and the STG is not exposed to direct sunlight.

2. Connect the external power supply to the STG.

3. Connect the external power supply to the power outlet.

4. Connect the USB connector to the USB port of the computer. The computer connection is necessary for programming the STG, but not for operating it (except in Batch mode).

5. Connect the catheter to the Stimulus IN / Raw data OUT connector of the STG3008-FA.

6. (Optional) Connect the required Trigger In input with BNC cables to instruments that produce TTL signals for triggering the STG.

7. (Optional) Connect the Sync Out output with BNC cables to following instruments that you want to be triggered by TTL signals from the STG, for example to one of the 16 digital inputs of the MC_Card, or of an USB based data acquisition.

8. Switch the STG on by pressing the toggle switch on the rear panel.

STG3008-FA Manual Illustration of the STG3008-FA front and rear panel with connectors

STG3008-FA Front Panel

STG3008-FA Rear Panel

STG3008-FA Front Panel

STG3008-FA Rear Panel

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 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.

Important: Please make sure that you have full control over your computer as an administrator. Otherwise, it is possible that the installed hardware does not work properly.

If there are any problems, and you need to install or update the driver manually, please see the MC_Stimulus II Help for more information.

3.4 Installing the Software

System requirements

Software: One of the following Microsoft Windows ® operating systems is required: Windows 7, Vista or Windows XP (English and German versions supported).

Hardware: USB port (2.0 High Speed)

First Use of the Stimulus Generator

Installing the software

Please check the system requirements before you install the software. MCS cannot guarantee that the software works properly if these requirements are not fulfilled.

Important: Please make sure that you have full control over your computer as an administrator. Otherwise, is possible that the installed software does not work properly.

1. Double-click Setup.exe on the installation volume. The installation assistant will show up and guide you through the installation procedure.

2. Follow the instructions of the installation assistant.

Select radio button "STG3008-FA". When you have finished the installation of the MC_Stimulus II software and the STG driver, you can now operate the STG3008-FA.

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 STG3008-FA on.

3. Set up your stimuli with the MC_Stimulus II program.

4. Send the stimulus sequence from a MC_Stimulus II file to the STG.

5. Start the STG either manually by pressing the Start / Stop button on the front panel, with the software controls, or with an external trigger.

Creating stimuli

Stimuli are created user-friendly by entering the desired pulses (rectangular, ramp, or sine waveforms) into a MC_Stimulus worksheet. Waveforms can be combined freely to create virtually any stimulus pattern. Created stimuli are displayed in a WYSIWYG window.

Starting stimulation

Note: You need a computer connection only when you are using the software controls for starting and stopping the stimulus generator. When you are using the STG interface or an external control (trigger, you can disconnect the stimulus generator from the computer and operate it independently. But you cannot remove the STG from the power connection. The memory is cleared when the STG has lost power.

After the download of the stimulus file on the STG, you can start the stimulation. There are several ways to start the STG.

MC_Stimulus II interface:

You can start the stimulation directly after the download (with the command

Download and Start

stop stimulation with the command Stop Start command is considered as activating the trigger input and the Sync Out

output. Likewise, all channels are stopped when you click Stop.

You can start the stimulation after download

or also later with the command Start . You can

. Starting the STG by using the

on the trigger. Please use

STG interface:

the combined LED / Start / Stop buttons stimulation manual whenever you want by clicking the corresponding LED / Start / Stop button. The LED indicates the status: Grey means trigger off, red means trigger on. In STG3008-FA only trigger 1 is available.

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 the trigger input, that is, all channels are started and stopped, and the Sync Out output is active when the STG is started. Pressing the Start / Stop button stops the stimulation if at least

one channel is still active in the moment of the trigger

. You can start and stop the

STG3008-FA Manual

event (indicated by the lighting SWEEP LED). Pressing the button starts stimulation only if no channel is active (dark SWEEP LED)

External control:

You can start the stimulation on a trigger from an external device, for example, a switch. You can use the trigger input to trigger the analog output channels that you have assigned to it. The trigger works in a similar way as when you press the Start / Stop button. You can choose the action that will be taken when one of the channels that are assigned to the trigger input is still active. Either the stimulus protocols on the triggered channels are stopped or restarted; or the trigger event is ignored. You can assign the Sync Out to the trigger input. The default settings define that Sync Out is active when Trigger In is triggered. Please see chapter "Trigger Settings" for more details.

STG status control

Three status control LEDs (light-emitting diode) are present on the front panel of the STG to give you a quick overview on its status.

POWER

PROG

SWEEP

STG has been switched on.

Stimulus file was downloaded to STG. STG is now ready for operation.

Stimulation is running, that is, at least one output channel is active.

MC_Stimulus II status control

The top part of the MC_Stimulus II status control refers to the active instance of the MC_Stimulus II program instance and the STG that is controlled by this instance. All information in this part is saved on the STG. The information is updated in the MC_Stimulus II main window when the connection to the STG is changed or interrupted.

Status light Color Meaning

Connected

Green STG is connected and switched on. The serial number serves as an ID for

the controlled STG and is displayed on the left. On the STG menu, click Select Device to select another STG connected to a different USB port from the drop-down list to switch STGs.

Programmed

Green Stimulus file in voltage mode has been downloaded to STG. STG is now

ready for operation. File name and path of the *.stm file that was downloaded onto the STG are displayed on the right.

Orange Stimulus file in current mode has been downloaded to STG. STG is now

ready for operation. File name and path of the *.stm file that was downloaded onto the STG are displayed on the right.

Sweep

Red

Indicates the active trigger (up to eight). Each stimulation channel can be assigned to any trigger. If all eight channels are assigned to trigger one for example, only one sweep indicator will light up, even though all stimulation channels can be active. See also chapter "Triggering Stimulation".

STG and Stimulus Protocol Information:

4.2 Operating the Amplifier

Switching between Stimulation and Recording Mode

The STG3008-FA is a stimulus generator of STG3000 series combined with a filter amplifier with four selectable gain factors: 100, 200, 500, or 1000.

Please click "Edit" menu and select "Filter Amplifier Control".

Operating the STG

The “Filter Amplifier Control” settings are saved in the current MC_Stimulus II protocol. After download, the STG3008-FA is set accordingly.

Thus, it is easy to switch between different measuring or stimulation settings by loading several MC_Stimulus II worksheets. Then you can download the protocol with the desired settings.

If the STG3008-FA is switched off and on again, the settings for all eight channels are reset to “Measure”, and the last downloaded filter amplifier gain is retained. This reset enables measurements with the STG3008-FA without using the MC_Stimulus II software, of course without stimulation, respectively.

STG3008-FA Manual

The "Filter Amplifier Control" dialog.

Selecting the "Filter Amplifier Gain"

You can choose among four gain settings from factor 100 to 1000.

In the "Filter Amplifier Gain" window, please click one of the radio buttons to select the gain factor.

Selecting the "Measure / Stimulate" mode

In the "Measure / Stimulate" window you can toggle between stimulation and recording mode for each of the eight channels separately.

Please click the respective radio buttons for the channels in use.

Important: A ground electrode connected to the ground of the STG3008-FA amplifier is required for proper use. The ground of the stimulation is connected to the ground of the amplifier inside the device. The amplifier ground is the reference point for both stimulation and recording. Without an appropriate grounding, the behavior of the system becomes unpredictable. The ground electrode should have a large surface area, for example, a liquid gel adhesive electrode. It is best positioned in an electrically inactive region (not near muscle, nor heart), but as near to the recording site as possible, for example, at the belly.

Operating the STG

4.3 Operating Multiple STGs

If you have more than one STG connected to the same computer, please click "Select Device" under "STG" in main menu. In the "Select Device" dialog you can choose via serial number 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.

 Click Select Device under "STG" in main menu. Select the serial number of the desired STG from

the STG list.

 You can open multiple instances of the MC_Stimulus II program and control multiple STGs at the

same time. Please make sure that you control each STG only by one MC_Stimulus II instance.

 You can also open only one MC_Stimulus II instance and control multiple STGs one after the

other by the same instance. Simply change the settings in the Select Device dialog and select the next STG when you have finished to program the first. The STGs can be operated without a computer connection.

5 Programming Stimulus Protocols

5.1 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. Select a Pulse type (either rectangular, ramp, or sine).

4. Enter the desired voltage steps and a time length for each step.

The according pulse is displayed in the WYSIWYG display at once.

STG3008-FA Manual

5.2 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. The minimum voltage resolution is 1 mV, the current resolution is 200 nA. Please regard also the minimum and maximum output voltage / current of your STG version. If you enter voltage or current values outside the STG's limit, the invalid value will be changed automatically when you download the protocol. Cells with changed values will be highlighted in yellow.

Note: If you work near the resolution limits of the STG, the output pulses may differ from the

programmed pulses. In this case, you should check the output with an oscilloscope. Please see

also the "Analog Output Signals" chapter.

Please note that the memory of the STG3008-FA is limited (64 MB). You will get an error message if the memory is full.

For the digital Sync Out channel, only TTL pulses with bit patterns of 0 (LOW) and 1 (HIGH) can be programmed. A logical state of 1 (HIGH) results in a 3.3 V output signal, and a logical state of 0 (LOW) results in a 0 V output. Please note that the digital output is sent about 20 μs faster than the analog output. Please see also the "Triggering Stimulation" chapter.

Rectangular pulse type

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.

Sine wave pulse type

 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.

STG3008-FA Manual

5.3 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. In the preceding example, the rectangular pulse in row 1 is repeated twice. You can also group several rows and repeat them altogether. In the example, pulses from rows 1 to 4 are grouped and repeated three times.

Repeating rows

 Type the number of repeats into the Row Repeat cell of the appropriate row.

The pulses of the complete row are repeated the specified number of times.

Grouping and repeating groups

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.

Programming Stimulus Protocols

4. Type the number of repeats into the merged Group Repeat cell.

Repeating complete pulse protocols (autorepeat function), Continuous Mode

You can repeat the complete stimulus on all output channels that are triggered by the same trigger. This means, each time when a trigger event occurs, the complete stimuli on all corresponding output channels are repeated for the specified number of times. If the stimuli have different lengths, the starting points are synchronized. For example, if channel 1 has a stimulus with a length of 500 ms, and channel 2 of 1000 ms, and both are triggered by the same trigger event, channel 1 waits 500 ms for the repeat until the output stream of channel 2 has been finished.

Note: The Sync Out signal for the corresponding trigger is repeated as well each time the stimulus is repeated.

Hint: You can repeat the complete stimulus protocol that is assigned to a trigger continuously by using the Continuous Mode setting. Continuous mode can be activated in the main window or under Trigger Settings. The STG has then to be stopped manually by the user. You can use this feature regardless whether you use an external trigger input or not. When you press the Start button, this is considered as if all four trigger inputs were active. When you use Continuous Mode, the repeats entered in the Trigger Settings dialog box are disabled.

1. On the STG menu, click Trigger Settings.

2. Enter the number of repeats for each trigger separately. 0 repeats the output signals continuously.

STG3008-FA Manual

In the following example, the stimuli on output channels 1, 2, 4, 5 and channel 7 and 8, that are all triggered by Trigger 1, are repeated five times after the trigger event, each time accompanied by the Sync Out 1 output.

Repeating complete pulse protocols, Gating Trigger

Repeated stimulation of complete protocols can also be controlled by a gating trigger. Channels associated with the Trigger input will be active as long as the condition of the Trigger is 1 (HIGH) and switched off as soon as the condition becomes 0 (LOW). Gating trigger function can be enabled in the Trigger Settings menu.

Programming Stimulus Protocols

5.4 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.

Inverting pulses in a column

1. Click any Value column header to select a column. The selected column is highlighted in black.

STG3008-FA Manual

2. Right-click and click Invert Selection.

The polarity of the signals is switched from positive to negative and vice versa.

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.

Shifting time or voltage / current values

You enter a value, which is added arithmetically to all values in the selected column. For example, if you enter "-50", -50 is added to all values.

1. Click any Value or Time column header to select a column. The selected column is highlighted in black.

2. Right-click and click Increment Selection.

3. Under Type of Increment, select Shift.

4. Enter the desired value.

Programming Stimulus Protocols

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.

STG3008-FA Manual

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. With this feature, you can easily set up time or voltage increments.

1. Under Type of Increment, select Count.

2. Enter the desired start value.

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.

Programming Stimulus Protocols

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.

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.

STG3008-FA Manual

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. You define the Start and End value and either the Step Size (Start - Stop - Step Size) or the number of Steps (Start - Stop - # of Steps). Alternatively, you can enter the Step Size and the Number of Steps (Start - Step Size - # of Steps). According to these specifications, rows are inserted and the column is filled automatically.

In the following example, the Autofill feature has been used to create a voltage step series from 20 mV to 500 mV with an increment of 20 mV.

1. Click any Value or Time column header to select a column. The selected column is highlighted in black.

2. Right-click and click Autofill.

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

5.5 Auto Sync for Autocreating Trigger Pulses

If you want to synchronize other devices with the stimulus generator STG3008-FA, you have to set up the digital output of the Sync Out channel in synchrony to the stimulus pulses. This may sometimes be a bit tricky and time consuming, especially for complex stimulus protocols.

The Auto Sync feature is intended for making the work with MC_Stimulus II more efficient: Digital Sync Out TTL pulses synchronous to stimulus pulses are generated automatically by this feature. Each time an analog channel generates a pulse (that is, its value is not equal to zero), the logical state of the Sync Out channel is set to HIGH (=1). You can set the time offset of the TTL's rising edge before the stimulus pulse and of the TTL's falling edge after the pulse. If you change the stimulus protocol, corresponding Auto Sync pulses are updated on the fly.

On the Edit menu, click Auto Sync Settings. The Auto Sync Settings dialog box appears.

1. Assign the analog stimulus channels that will be used as the basis for autocreating the protocols on the Sync Out channel. For example, if you use only stimulus channel 1, select Ch1 in Sync1.

2. Set the time offset of the TTL’s rising edge before the stimulus pulse (Pre Time) and of the TTL’s falling edge after the pulse (Post Time)

STG3008-FA Manual

3. 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.) The worksheets of the Sync Out channels assigned to the Auto Sync feature will be unavailable, that is, you cannot edit them manually. The following screen shot shows an example of a monophasic 100 μs voltage pulse on channel 1 and the corresponding Auto Sync pulse (Pre Time 0 μs, Post Time 100 μs) on Sync Out 1.

4. If you later choose to edit the Sync Out worksheets of the active file manually, you can deselect the Auto Sync feature on the Settings menu. Any information in the Sync Out worksheets that was there before the Auto Sync option was enabled will be restored; and all worksheets will be available for manual editing.

5.6 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 each of the up to 8 channels. You can adjust the level offline and download the information onto the stimulus generator manually afterward, or you can adjust the level on-the-fly, without stopping the running stimulation. This feature is especially convenient for testing out thresholds that evoke a biological response.

Note: The error messages that are displayed when the stimulus amplitude is not set to zero at the end of the protocol or when the time length of stimulus protocols is different on individual channels can present a nuisance when adjusting the level on-the-fly. These error messages can be switched off by deselecting the option Enable Compiler Warnings on the Settings menu.

1. On the Edit menu, click Amplitude. The Amplitude dialog box opens. You can drag and drop it anywhere you like on the screen, also outside the main window of the MC_Stimulus II program. This is especially convenient when you are using two monitors.

2. Select the option Auto Download if you want to adjust the stimulus intensity level on-the-fly. Deselect the option if you want to download the changes manually later.

3. Select the option Change All if you want to adjust the stimulus intensity to the same level on all channels. Deselect the option if you want to set individual channels to different levels.

4. Drag the slider with the mouse for adjusting the stimulus intensity in the range of 0 to200 percent of the programmed stimulus amplitudes. The WYSIWYG display is updated automatically. The worksheet is not updated. It always relates to the stimulus protocol that you programmed initially. If Auto Download is selected, changes are immediately downloaded onto the stimulator after releasing the slider, and the stimulus protocol is restarted from the beginning, with the adjusted stimulus intensity level.

5. If Auto Download was not selected, you need to download the stimulus protocol manually for changes to take place.

Programming Stimulus Protocols

6. You can click the Reset All button to set the level on all channels back to 100 percent.

Stimulus Intensity dialog box of the STG3008-FA

Channel 1 is set to 100 %, that is, the stimulus protocol will be downloaded onto the stimulus generator as it was programmed in the worksheet. Channel 2 is set to 50 %, that is, all stimulus amplitudes programmed on channel 2 are half, channel 3 is set to 150 %, and channel 4 is set to 100 %,channel 5 and 6 are set to 200, that is, all stimulus amplitudes are doubled.

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 3.1.2

ASCII import example: Stimulating with biopotential waveforms

Shown is a single spike recorded from an organotypic hippocampal culture. The spike waveform was exported as ASCII from MC_Rack and imported into the MC_Stimulus II program.

Warning: All previous records in the active MC_Stimulus II file (.*.stm) file are overwritten. Please create a new file and import the data into an empty worksheet to avoid data loss.

1. On the File menu, click Import ASCII File. The Open dialog box appears.

2. Select an appropriate ASCII file and click Open. The stimuli from the ASCII file are loaded into the active MC_Stimulus worksheet. All previous records are overwritten. Channels that are not present in the ASCII file are empty. You can now edit and download the stimulus file as usual.

If the file does not fulfill the requirements of a stimulus file, an error message will show up and tell you in which line the first error occurs. See "Supported File Format" for more information about supported ASCII files.

STG3008-FA 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.

6.3 Supported File Formats

The ASCII text must exactly follow the specifications below. The parameters in angle brackets are placeholders for any valid numbers or strings.

Hint: You can set up files conveniently in any standard spreadsheet program and save them as tab-delimited ASCII.

General

 The file name and the file name extension are not important. You can use any extension

you like, for example *.txt, or *.dat, or any other.

 Comments are introduced by the number sign #. The rest of the line after # is only for your

information; it is completely ignored when executing the stimulus file. (You do not need comments, of course, but it is convenient for documentation.)

Hint: Use # to comment lines out. That is, you can disable lines without removing it from the file. Thus, you can keep the lines for later uses.

 Blank lines are ignored.

 The spelling is strict. The MC_Stimulus II program does not recognize a keyword if it is misspelled

or if even only one character is missing, but it is not case-sensitive.

 The file has the following structure.

1. File header

2. Data

File header

The first two non comment lines have to be the following lines. Files for older versions of the import filter (version 1.00) can be imported with the current version as well.

Multi Channel Systems MC_Stimulus II ASCII import Version 1.10

The next three lines have to be the following lines (in any order).

channels: <number> output mode: <mode> format: <format number>

Make sure you define the total number of channels for the used STG properly (4 channels for a STG with 4 channels, 8 channels for a STG with 8 channels, and so on), according to the software version. You can select the maximum number of channels during the installation of MC_Stimulus II. On the Help menu, click About MC_Stimulus II to check your current software version.

ASCII Import/Export

Example:

You have to include the following line in the ASCII file if you have installed MC_Stimulus II for STG3008-FA

channels: 4

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.

channel: <channel number>

You can specify analog output channels from 1 to 8 (limited by the number of analog output channels of the connected STG, of course).

The data follows after the channel specification line; three format types are available. All format types follow the MC_Stimulus II worksheet's structure of rows and columns. See the description of the worksheet for more details. Columns are separated by blanks or tabs. The first line has to contain the column headers. The following lines contain the voltage/current and time values. Rows/lines are separated by a carriage return or line feed (CR / LF). This is the Windows standard control character inserted when you press the ENTER key.

The voltage unit is mV and the current unit is μA. Please make sure that all values are in the ranges specified for the STG you use. For the Sync Out channel, only values of 0 and 1 are allowed.

The time unit is μs. Time values can be in the range from 20 to 18.000.000.000 (20 μs to 5 h). Time base of the STG is 20 μs, so only times that are multiples of 20 μs are valid.

Note: Please make sure that there are no additional tabs or characters, which would lead to an error message. Show tabs and spaces in your text editor and check the file before importing it.

Format type 1

This is a basic format with two columns of Value and Time each, without Repeat functionality.

value time value time

Format type 2

With this format, you can repeat rows in the same way as described for the worksheet. Group repeat is not available.

value time value time repeat

STG3008-FA 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.

The same file would look like this in a standard text editor program. You can see the tabs, spaces, and CR/LF.

ASCII Import/Export

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. This format is the standard format if you want to import data for example from Excel.

This format type is generated when exporting MC_Stimulus II files as ASCII.

value time

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.

You can only use the rectangular type (0) for the Sync Out channels.

Important: When setting up rectangular or sine waveforms in this format type, you need only one value column for defining the amplitude, but you have to define both value columns even so. The first value column is ignored for rectangular and sine pulse types by the MC_Stimulus II program.

pulse (0, 1, 2) value value time

STG3008-FA Manual

Example:

This is an ASCII file viewed in a standard text editor program. You can see the tabs, spaces, and CR /LF.

For demonstration purposes, a ramp type pulse was programmed on the first channel, a sine wave on the second channel, a rectangular waveform on the third channel, and mixed pulse types on the fourth channel.

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. You can directly import the MC_Rack export files into MC_Stimulus II.

time value

You can use this format with or without header.

Example:

The following picture shows a file of format type 6 without header.

STG3008-FA 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.

The value microvolt is normally used for data recording in voltage mode of MC_Rack. The STG generates voltage pulses in values of millivolt. Please use the “Amplification” factor of the ASCII Import Dialog to convert μV in mV, otherwise the output of the STG is zero.

The amplification factor is generally applied in files with and without header.

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:

ASCII Import/Export

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.

Settings for ASCII import files with or without header:

Please choose the factor of amplification in "Amplification". This is very helpful, for example, for importing data recorded in microvolt μV and now needed in millivolt mV. That means, the factor is 1000 or – for higher stimulation signals - may be 10000. Please see chapter "Format Type 6" above.

Important: MC_Stimulus II uses the header of an ASCII import file, if a header is available. If no header is available, MC_Stimulus II applies the settings of the dialog "ASCII Import Setting".

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 check boxes in the main window of the program.

 Clear the check box of all channels that are not in use. All channels that are not selected

are removed from the display.

7.2 Display Settings

You can toggle between a decimal time scale in seconds (floating point numbers) and a time of day scale in the format hh:mm:ss:zzz, where h means hour, m is minute, s is second, and z

is millisecond.

 Under Settings, click X Axis Time Format. Select the option to enable the time of day scale.

Deselect the option to switch to the decimal time scale.

STG3008-FA 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

Enable scaling

Zoom out

Zoom in

Reset

Size to fit

Show measure tool

Scrolling the axes

You can scroll the stimuli forward and backward along the time axis, and up and down along the voltage/current axis.

1. Click

to enable the scrolling.

Scroll the axes by clicking and dragging with your mouse.

Zoom the axes by clicking and dragging with your mouse.

Reduces the time scale.

Magnifies the time scale.

Resets the axes of all channels to the default values.

Adjusts the ranges to fit the largest displayed stimulus.

A horizontal bar is shown that displays the current / voltage and the time value of the intersection point. Drag the bar with the mouse.

2. Click the axis you like to scroll. The mouse pointer becomes a hand.

3. While holding down the mouse button, move the axis to the left and right, or up and down.

- OR You can use the keyboard: Press LEFT ARROW or DOWN ARROW to move the axis to the left (down), RIGHT ARROW or UP ARROW to move the axis to the right (up).

- OR - Use the PAGE UP and PAGE DOWN keys for a faster scrolling (larger steps): PAGE DOWN to move to the left (down), PAGE UP to move to the right (up).

Zooming the display

Stimulus 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.

- OR - Use the PAGE UP and PAGE DOWN keys for a faster scrolling (larger steps): PAGE DOWN to zoom out, PAGE UP to zoom in.

Size to fit

 Click

to size the display to fit. The ranges are automatically adjusted to fit the maximum amplitude of each stimulus. The range of the time axis will be set to fit the longest signal.

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. The stimulus display is independent from the worksheet and from the download. Verify that you download only the channels that you want to use. Do not start the STG if you are not sure about the channel configuration or the nature of the downloaded file.

Select the channels for downloading under Download Channel and Download Sync.

On the STG menu, click Download or click

channels onto the STG or Download and Start and start the stimulation directly after the complete download.

When downloading files created in MC_Stimulus II software to a stimulus generator of the STG3000 series 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. This mode should always be used when large and complicated stimulation patterns are used, for example white noise stimulation.

Disable / enable warning messages

Cancel this option to disable the message boxes displaying compiler warnings during stimulus download.

The two error messages that can be disabled are: "warning: signal length shorter than the maximum" and "warning: non zero last amplitude value". They may present a nuisance if you download multiple stimulus files in batch mode.

 On the Settings menu, select or deselect Enable Compiler Warnings.

on the toolbar to download only the selected

to download only the selected channels

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.

 Tile: Use this command to arrange the windows so that they are not overlapping.

 Arrange Icons: Use this command to line up minimized windows.

 You can resize the windows with your mouse.

 Click an empty area on the toolbar, and then drag the toolbar to a new position.

9.2 Menu Bar

You will find most software features in the pull-down menus of the main window. Each menu displays a list of commands. Commands that are not available at the moment appear shaded.

Use the ...

 File menu to create new files, save files, import ASCII files, and print the stimulus worksheet.

 Edit menu for general editing features like copy and paste rows, remove the last entered value

(Undo), remove and insert rows into the active worksheet. You can also right-click on a row and select these commands. Click Clear Signal to delete all values in the active worksheet. You can also specify the output ranges according to the connected STG on this menu. Please see the technical specifications of your STG.

 The STG menu contains all commands directly relating to the hardware, for example download

commands, start and stop the STG, and trigger configurations.

 You can open, start, and stop a batch run of several files on the Batch menu.

 Signal menu for nice editing features like editing whole columns, and autocreate signals.

You can also right-click on a column and select these commands.

 View and Window menu to customize the main window.

 Settings menu to define general settings of the software.

 Help menu to open the MC_Stimulus II Help and to display the About dialog where you

can find information about the hardware, software, and firmware versions. You will need this information when you contact the support.

STG3008-FA Manual

9.3 Toolbar

For your convenience, you will find some of the more commonly used commands as a button on the toolbar.

New File

Open File

Save File

Cut Row

Copy Row

Paste Row

Information Opens the About dialog, where you can find information about the

Download Downloads stimulation file to the connected STG (only available if STG

Download and Start

Start

Stop

Creates a new MC_Stimulus II file (*.stm) file.

Opens a previously saved MC_Stimulus II file (*.stm) file.

Saves the *.stm file to the chosen destination.

Deletes selected row(s) and sends deleted row(s) to clipboard.

Sends selected row(s) to clipboard.

Pastes row(s) from clipboard and overwrites row(s) starting at the selected row.

Prints active channel of active worksheet.

hardware, software, and firmware versions.

has active computer connection).

Downloads and starts stimulation file to the connected STG (only available if STG has active computer connection).

Starts downloaded stimulation file (only available if STG has active computer connection).

Stops downloaded stimulation file (only available if STG has active computer connection).

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.

Shortcut key

CTRL+C

CTRL+D

CTRL+A

CTRL+N

CTRL+O

CTRL+P

CTRL+R

CTRL+S

CTRL+T

CTRL+V

CTRL+X

CTRL+Z

Copy Row

Download

Download and Start

Create New File

Open File

Start

Save file

Stop

Paste Row

Cut Row

Undo

Hint: Shortcut key combinations are also listed on the toolbar menus. For example, the File menu shows that the shortcut key for Save is CTRL+S.

9.5 File Menu

You can save MC_Stimulus II files for later use. This is very convenient if you have various similar experimental setups, or if you like to repeat an experiment later.

Open a file

You may open previously saved files for similar experimental setups.

General Software Features

1. On the File menu or on the toolbar, click Open

2. Browse your folders and choose the desired file. You may only open MC_Stimulus II files (*.stm).

3. Click Open.

The selected file opens.

Save a file

1. On the File menu or on the toolbar, click Save

The currently active worksheet is now saved.

You may open the file using MC_Stimulus II later on to continue your experiment.

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".

Export ASCII File

Please see chapter "ASCII Imort / Export"

Printing a channel

1. On the File menu, click Print Setup to select a printer, paper format, and so on.

2. Click Print Preview to preview the print output.

3. Click Print

to print out the active channel of the active worksheet.

STG3008-FA Manual

9.6 Settings Menu

Enable Compiler Warnings

Cancel this option to disable the message boxes displaying compiler warnings during stimulus download.

The two error messages that can be disabled are: "Warning: Signal length shorter than the maximum" and "Warning: Non zero last amplitude value". They may present a nuisance if you download multiple stimulus files in batch mode, or if you want to adjust the stimulus intensity level on the fly.

 On the Settings menu, select or deselect Enable Compiler Warnings.

10 Synchronizing Events

10.1 Digital Output Signals (Sync Out)

The output of the digital Sync Out output 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.

You can program the output signal of the Sync Out channel in the same way as the analog output signals, but due to the nature of a digital signal, only values of 0 and 1 are allowed. A Sync Out signal is generated each time when the STG is started.

The output signal can be used for triggering external devices, for example, the any data acquisition devices.

Note: Please note that if you use it for triggering the MC_Card, you should use output signals that have a duration of at least 200 μs. Otherwise, it can happen that the MC_Card ignores trigger events.

The Sync Out output is active when the STG is started by pressing the Start / Stop button, or by using the software command Start on the STG menu.

If you are using the Trigger In input for starting the STG, ther Sync Out channel is controlled by the Trigger In channel. Sync Out 1 is active when Trigger In 1 is triggered.

If you use the Repeat feature in the Trigger Settings dialog box, the Sync Out signal is repeated as well as the selected analog output signals.

Note: No Sync Out signal is sent when the STG is stopped on a trigger event or by pressing the

Start / Stop button, that is, if the trigger event occurs or the button is pressed when the STG

has still been active.

10.2 Triggering Stimulation (Trigger In)

The external trigger input has to be a TTL signal of at least 40 +/- 10 μs length. TTL pulses shorter than that may not be recognized by the stimulus generator.

A TTL pulse is defined as a digital signal for communication between two devices. A voltage between 0 V and 0.8 V is considered as a logical state of 0 (LOW), and a voltage between 2 V and 3.3 V means a 1 (HIGH). It is the same kind of signal as the output signal of the Sync Out output of the STG.

In STG3008-FA there is one Sync Out output for one trigger input. You can assign the Sync Out and the analog channels to the trigger input in the Trigger Settings dialog box. The default settings is that Sync Out 1 is active when Trigger In 1 is triggered. See also "Digital Output Signals" for more information on the Sync Out channel.

The Sweep status display (LED Start / Stop buttons) in the main window program shows active sweeps that were started by the trigger. That means, the status lamp that corresponds to trigger 1 lights red as long as any channel triggered by trigger 1 is active. Please note that the number of the analog output channel is irrelevant, the Sweep status lamp refers only to the trigger. Example: Assume that channel 4 is assigned to trigger 1. When channel 4

is active, the Sweep lamp lights red

, because the Sweep lamp refers to trigger 1.

of the

STG3008-FA Manual

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. It is also possible to set up advanced experiments where stimulation depends on preceding activities of the studied object.

The following picture shows a suggested circuit diagram for a switch used for remote controlling. The resistor and capacitor work as a low-pass filter on the TTL signal and are necessary to reduce ringing of the signal.

10.3 Trigger Settings

Triggering output channels (Standard mode)

You can use the trigger input for triggering the output channel. The trigger settings are saved in the currently active MC_Stimulus output file (*.stm). All eight analog output channels are assigned to “Trigger 1” by default in the “Trigger Settings” dialog box in the “Edit” menu.

The “Multi-File” and the “Extended Multi-File” mode are not available in STG3008-FA.

Triggered action when channel(s) still active

Synchronizing Events

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

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. The trigger event starts stimulation only if no channel that has been assigned to this trigger is active.

Restart: The stimulus protocols on all channels assigned to this trigger are started at the trigger event, regardless of the activity on these channels.

to show the advanced options:

Ignore: The trigger event is ignored when any channel assigned to this trigger is active. The trigger event starts stimulation only if no channel that has been assigned to this trigger is active.

STG3008-FA Manual

Use Trigger as Gate

Channels associated with a Trigger input will be active as long as the condition of that trigger is 1 (HIGH) and switched off as soon as the condition becomes 0 (LOW). If the stimulation protocol is shorter than the gate, it will stop at the predefined time, regardless of the gating trigger. If the stimulation protocol is longer than the gating trigger, stimulation will stop when the gating trigger ends. For example, if you want to produce a repeated rectangular pulses that last as long as the gating trigger is HIGH, you can do the following: program a single rectangular pulse and activate the continuous mode. The pulses will start as soon as the gating trigger becomes HIGH, and stop as soon as the gating trigger becomes LOW. If the voltage of the stimulation channel is different from 0 at the time the gating trigger ends, the channel will be switched off immediately. If you stop the stimulating protocol manually during the gating trigger in HIGH, stimulation is stopped but immediately restarted, and goes on until the gating trigger ends.

Warning: Once selected, this setting will become the default setting for all opened files, until unselected. So if you observe unexpected behaviour when triggering the STG, check the Trigger settings.

Sweep Count

The number of sweeps are counted and displayed for each of the four 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.

Sweeps are not counted online, the final number is displayed after the STG has been stopped. The number of sweeps per channel is not put to zero automatically every time the stimulation is started. Instead, a reset only happens if a trigger is again used in the new stimulation. So, if a stimulation file uses trigger one and two with a repeat of three each, the display will show 1:3 2:3 3:0 4:0 at the end of the stimulation. If afterwards for example a stimulation file is started which uses only trigger four in continuous mode, and this file is stopped after 15 repeats of the programmed stimulation pattern, the display will show 1:3 2:3 3:0 4:15.

Synchronizing Events

10.4 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 next file in the list is downloaded, and so on, until the last file in the batch list has been run.

Triggering a sequence of stimulation protocols

The Batch mode is useful if you want to start a sequence of different stimulation protocols one after the other on the same trigger (Trigger 1). Please make sure that you have assigned all channels to Trigger 1 in the Trigger Settings dialog box. You set up the protocols and save them as separate stimulus files. Then, you set up a batch file with a list of the desired stimulus files.

 The first trigger event starts the first file in the list.

 When a file has been completed, the next file in the list is downloaded automatically.

 When a trigger event occurs after the file has been run, the next file is started, and so on.

 When a trigger event occurs during the run of a file, the run is stopped, and the next file

in the list is downloaded. The next trigger event starts the next file.

 Deselect the option Start STG after Batch Download on the Settings menu if you want to start

the protocols on a trigger or manually with the software or hardware controls. If the option

Start STG after Batch Download on the Settings menu is selected, the STG starts each file directly after the download without waiting for a trigger event.

Note: Only Trigger 1 is available for triggering in Batch mode. Do not use any other trigger inputs.

Splitting up stimulation protocols to circumvent the memory limitation

If the option Start STG after Batch Download on the Settings menu is selected, the STG starts each file directly after the download, which is only useful in the (unlikely) case that you need to circumvent the memory limitation of the STG. Split up your pulse protocol into several stimulus files and run them in Batch mode.

Setting up a batch file

You have to set up a batch file (.stb) first, which lists the full path of all files that you like to download as a batch. The batch file has to be exactly in the following format. This example is a batch list with three different pulse protocols. Replace the file paths with the correct path of the files of your choice.

Multi Channel Systems MCS MC_Stimulus Batch Control File Version 1.00 c:\Program Files\Multi Channel Systems\MC_Stimulus II\BatchExample\Baseline.stm c:\Program Files\Multi Channel Systems\MC_Stimulus II\BatchExample\Tetanus.stm c:\Program Files\Multi Channel Systems\MC_Stimulus II\BatchExample\TestResponse.stm

STG3008-FA Manual

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. It lists all stimulus files in the batch and the duration of stimulation.

4. On the Batch menu, click Start to start the download of the first file in the batch list and the STG if the option Start STG after Batch Download on the Settings menu is selected. The progress of the pulse protocol is displayed in the Status column of the Batch Status Display.

5. Click Stop on the Batch menu to stop the batch if necessary.

6. Close the Batch Status Display with the Close command.

Warning: The STG starts immediately after the download if the option Start STG after Batch

Download on the Settings menu has been selected. Make sure to deselect this option if you

do not want to start the stimulation right away.

Autorepeat option

If you select the Autorepeat Batch Mode option on the Settings menu, the batch is restarted with the first file after the last file in the batch has been finished.

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 (the higher the electrode resistance, the lower is the output current).

In current mode, the stimulus generator guarantees a stable current output independent of the electrode resistance, where the voltage is defined by Ohm's law. The higher the electrode resistance, the higher is the output voltage. Therefore, the kinetic properties of the stimulus output is affected by the load resistance,which is usually the electrode resistance. If the resistance is too high, the output current is limited by the compliance voltage, that is, too high resistances will result in a clipping of the output signal.

Please consider the time and voltage / current resolution of the stimulus generator. The minimum pulse has an amplitude of 1 mV in voltage mode or 200 nA in current mode (supported by MC_Stimulus II; the firmware / DLL supports a 14 bit resolution, which means 200 nA for an output current range of 0.8 mA, and a time length of 20 μs. Please note that if you work near these limits, that is, if you use very small amplitudes or very short pulses, the output waveform may not exactly match the programmed waveform.

Resolution Limits

Ground

All stimulation channels of the STG are optically isolated from each other. Each channel has an independent ground (GND), which is usually connected to the ground of the experimental setup, for example, the amplifier, so that all devices refer to the same ground. Please make sure that you always use the appropriate ground for the channel in use.

STG3008-FA 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. The output signals are inverted (multiplied by -1) if you use the - outputs.

 In the following example, you see a signal in the MC_Stimulus II display and the resulting

output signals for the different connection options (viewed in a MC_Rack Data Display).

Programmed stimulus protocol viewed in MC_Stimulus:

STG output signals:

Programmed stimulus protocol viewed in MC_Stimulus II.

Voltage output 1 V and Sync Out.

Analog Output Signals

The time lag between the Sync Out output, the trigger, and the voltage output is approximately 15 μs (+/- 2 μs)

STG3008-FA 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.

 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. The stimulus generator limits the output voltage to 75 V between + or - and GND. The guaranteed compliance voltage is +/- 60 V.

 The current output of the STG is limited by the compliance voltage and the electrode

impedance. If the maximum load resistance for a given current output is exceeded, the

compliance voltage (60 V between +I and GND) of the STG will not be sufficient for delivering enough current, and the output will be clipped. You can calculate the maximum load resistance by Ohm's law. For example, if you want to program a 100 μA pulse, the maximum load resistance will be 600 k. According to Ohm's law: R = U / I = 60 V / 100 μA = 600 k, that is, 60 V are sufficient for delivering a current of 100 μA at a load resistance of 600 kherefore, if you use current driven stimulation, you should always take the impedance of the stimulating electrodes into account when planning your stimulus protocol. You should also keep in mind that most electrodes or amplifiers support only limited voltages.

Screen shot from a standard oscilloscope triggered on the Sync Out pulse. 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).

11.4 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. If you have very time-

critical applications, or if you use very short pulses, you should check the output of the STG with an oscilloscope before starting the experiment.

Amplitude dependency of rise time

The rise time is independent from the current amplitude in the common range of amplitudes. The rise time (10 % /90 %) was measured with increasing current amplitudes (100 μA to 1600 μA) and a constant load resistance of 10 k. The output current is nearly constant up to amplitudes of 1100 μA, but increases about 0.3 μs until the maximum of 1600 μA amplitude is reached. The relationship is not linear as shown by the following curve.

Analog Output Signals

STG3008-FA Manual

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. Not shown are the results of the same measurement under the same conditions, except of the amplitude with a constant current amplitude of 100 μA. Up to a load resistance of 450 k, the results are congruent with 50 μA amplitude.



Stimulus output comparison

The following figures are examples for demonstrating how the amplitude and resistance will affect the kinetics of a current pulse. These images document also that in contrast to the current mode, in voltage mode, the rise time is constant and not dependent on the amplitude or load resistance.

The graphs were generated by a standard oscilloscope. The devices were set up according to the recommendations under "Voltage Mode" and "Current Mode". The same pulse protocol and the same channel number of the STG outputs were used for measuring the voltage and the current output.

Analog Output Signals

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. Rise time (10 % / 90 %) = 3 μs



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

STG3008-FA Manual

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.

Analog Output Signals

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. Rise time (10 % / 90 %) = 3 μs

STG3008-FA Manual 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. The approximate 3 μs rise time of the 500 μA current pulse is not higher than the rise time of the 50 μA pulse.

Analog Output Signals

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. Rise time (10 % / 90 %) = 12 μs

STG3008-FA Manual 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). Please keep in mind that the resistance of the oscilloscope probe with 10 M is parallel to the 1 M load resistance. That means, that the maximum of the load resistance is reduced to 900 k only.

11.5 Comparison of Output Signals in Current Mode

To show the different behavior 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

Example 1: Influence of the length of a current pulse 100 μs versus 20 μs with an amplitude of 1600 μA, which is at the maximum capacity of the STG3000 series (constant amplitude and load resistance).

Example 1a: Current pulse with programmed 1600 μA for 100 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 STG3000 series. Green trace = current output (+I), pink trace = TTL trigger output from the Sync Out.

Analog Output Signals

STG3008-FA Manual

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 STG3000 series. 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 STG3000 series.

Analog Output Signals

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 STG3000 series (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.

STG3008-FA Manual

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.

Result of Example 2: The current output signal is delivered unmodified without any influence of the length of the pulse, and an amplitude of 16 μA which is a hundredth of the limit of the maximum capacity of the STG3000 series

Analog Output Signals

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 Mis parallel toM of the probe of the oscilloscope. That means, the load resistance is reduced to 900 konly

The pulse is biphasic, and 16 μA which is a hundredth of the limit of the maximum capacity of the STG3000 series. Green trace = current output (+I), pink trace = TTL trigger output from the Sync Out.

Result of Example 3: The current output signal is delivered strongly modified because of the high load resistance of 1 M, and the duration of the pulse, 100 μs and the interval. Before the pulse is reaching its maximum, it has to turn into its invert phase. Before the pulse is reaching its minimum, it is cut off. Please see example 4: If the duration of pulse and interval is much longer, 1 ms, the pulse shape of the delivered signal is much better.

STG3008-FA Manual 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 Mis parallel toMof the probe of the oscilloscope. That means, the load resistance is reduced to 900 konly

The long pulse is biphasic, 50 μA. Green trace = current output (+I), pink trace = TTL trigger output from the Sync Out.

Result of Example 4: The current output signal is delivered negligible modified when the duration of the signal and the duration of the interval is long, for example 1 ms.

11.6 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. This effect takes place especially in current mode because the current cannot flow back to the stimulus generator due to the high output resistance in current mode and thus is kept in the electrode. A current source can constantly produce small currents, even though the current is set to zero. This might damage the connected electrodes over time. To avoid this problem, the STG3008-FA is equipped with switches that automatically disconnect the current outputs from the current source 1s after each programmed current stimulus. For the next stimulus, the current source is automatically reconnected.

To reduce the effect described above in current mode, you should use biphasic pulses for stimulation. The stimulus signal should be immediately followed by an inverse signal of the same area (product of current and time), which helps to discharge the electrode. The easiest way is to use the same signal amplitude with an opposite polarity.

Multi Channel Systems recommends using voltage driven stimulation. In voltage mode, it is not necessary to use biphasic stimulation for discharging the electrodes, because the electrode should be discharged at a voltage of 0, that is, it would be sufficient to apply the negative phase only.

Warning: When using MEA electrodes of TiN material, stimulation with higher amplitudes is possible if you apply the negative pulse first. Also, regard the safe charge-injection limit as described in the MEA manual. Otherwise, electrodes can be damaged during stimulation.

Analog Output Signals

The following illustration shows the effect of a biphasic current pulse on the discharge of the stimulation electrode. As you can see, the first monophasic pulse is followed immediately by a pulse of the opposite polarity and the same product of current and time.

Effect of a bipolar current pulse on the electrode voltage

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. This helps other users, and it helps MCS to optimize the instrument and the documentation.

Please pay attention to the safety and service information (chapter "Important Safety Advice" in the manual or help). Multi Channel Systems MCS GmbH has put all effort into making the product fully stable and reliable, but like all high-performance products, it has to be handled with care.

12.2 Technical Support

Contact your local retailer immediately if the cause of trouble remains unclear. Please understand that information on your hardware and software configuration is necessary to analyze and finally solve the problem you encounter.

If you have any questions or if any problem occurs that is not mentioned in this document, please contact your local retailer. The highly qualified staff will be glad to help you.

Please keep information on the following at hand

 Description of the error (the error message text or any other useful information) and of the

context in which the error occurred. Try to remember all steps you had performed immediately before the error occurred. The more information on the actual situation you can provide, the easier it is to track the problem.

 The serial number of the device. You will find it on the device or click on the Help menu,

click About .

 The software (SW) and hardware (HW) version you are currently using. On the Help menu,

click About. The displayed dialog box shows the version numbers.

 The operating system and service pack number on the connected computer.

 The hardware configuration (microprocessor, frequency, main memory, hard disk) of the

connected computer. This information is especially important if you have modified the computer or installed new hard- or software recently.

STG3008-FA 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.

Download

These error messages may occur during download on the STG. Please note that you can switch off some of these messages if they disturb your experiment. See chapter "Downloading Stimuli" for more details on downloading.

The worksheet is empty. No data is present that can be downloaded.

There is no stimulus generator connected to the computer or the STG may be switched off. Please check the computer connection and the status lamp of the STG.

There is no valid connection to an STG. Download of data is not possible. Please check the computer connection and the status lamp of the STG.

The last voltage / current values of the named channels are not zero. The current / voltage levels are set to zero after the last value. The last used values of these channels are kept until the STG is stopped.

Appendix

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).

The number of data columns has to be consistent for all lines in a given ASCII file (for example, value, time, value, time). This error message indicates that there is a current / voltage value or a time point missing in line 12.

The ASCII file contains current / voltage values outside the STG's range. For example, if the STG's output range is +8000 mV, all values above +8000 mV are set to +8000 mV.

STG3008-FA 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.

12.5 Signal is not Repeated / Pulse Train Fails

The STG fails to generate a train of pulses. When a pulse is programmed in MC_Stimulus II and then repeated (in the Trigger Settings dialog box) (with the Repeat option), the STG abruptly stops after it has generated the waveform only once. (If another STG is connected to the computer to run the same protocol, the stimulator has no problems on repeating the pulse.)

Possible causes:

? If you change the stimulus protocol after the download, even if only the number of repeats

were changed, you need to download the modified stimulus protocol to the STG. Otherwise, the changes will not be applied. (If another STG is connected to the computer, you will have to download the stimulus protocol, including the changes, to be able to stimulate at all.)

Select Download or Download and Start on the STG menu (or on the toolbar) after you made

any changes to the stimulus protocol in the MC_Stimulus program.

Appendix

Output Signal Does not Match Programmed Signal

The amplitude or the duration of the output pulses differs from the programmed signal.

Possible causes:

? The stimulus protocol works near the resolution limits of the STG, that is, the pulses are very short

or the amplitudes very low (smaller than 50 mV or 10 μA).

 Check the output signals with an oscilloscope and modify the pulse protocol so that the amplitude

and timing of the pulses will match your requirements.

? You operate the STG in current mode, and the electrode resistance of the stimulating

electrodes is too high. According to Ohm's law, the electrode resistance directly affects the kinetics of the current output. The rise time increases with an increasing electrode resistance. If the electrode resistance is too high for the compliance voltage, the output signal will be clipped.

 Try to stimulate in voltage mode.

 Try to use stimulating electrodes with a lower impedance.

 Check the output signals with an oscilloscope and modify the pulse protocol so that the amplitude

and timing of the pulses will match your requirements.

12.6 Strong Peak Artifacts

Strong discharges or other artefacts of the output voltage or current.

Possible causes:

? One or both current outputs are open, that is, nothing is connected to them. The stimulus

generator tries to hold a stable current against the indefinite resistance of the open current output. Therefore, the stimulus generator will increase the output voltage on the open current outputs to its maximum, which will result in a heavy load on the power supply. This situation may cause the power supply to become unstable, which may lead to artifacts on all channels.

 In current mode: Connect the unused current output to ground (GND). Please see also

the recommended setups in the chapter “Current Mode”.

STG3008-FA Manual

13 Appendix

13.1 Technical Specifications STG3008-FA

European Standard: EN 55011, EN 61000-6-1

General characteristics

Operating temperature 10 °C to 50 °C

Storage temperature 0 °C to 70 °C

Dimensions (W x D x H) 220 mm x 170 mm x 60 mm

Weight 1050 g

Fuse internal, 3.15 A slow blow

Supply voltage (external power supply) 100 to 240 VAC @ 47 to 63 Hz

Stimulus Generator

Number of stimulus generators 8

Output voltage range -8 V to + 8 V @ max. ± 20 mA

Output voltage resolution 1 mV

Rise time (10 % - 90 %) voltage 1.7 μs @ delta U = 8 V

Time lag between Sync Out and voltage output

15 μs ± 2 μs for continuous pulses 40 μs ± 5 μs for a first or a single pulse

Output current -1.6 mA to +1.6 mA @ max.± 120 V compliance

voltage (between +I and I)

Output current resolution 200 nA

Output current slope

Time lag between Sync Out and current

600 μA/μs @ R

15 μs ± 2 μs @ R

= 10 k

output, 0 - 100 μA

Rise time (10 % - 90 %) current, 0 - 100 μA

1.4 μs @ R

= 10 k

Resolution 14 bit

Time resolution 20 μs

Output signals Freely programmable (rectangular, ramp, sinus,

arbitrary

Maximum frequency (rectangular waveform) 25 kHz

Memory capacity for stores waveforms 64 MB

Timing on external trigger

Minimum time length of trigger input (TTL) 40 ± 10 μs

Time lag between trigger input and Sync Out 30 ± 10 μs

Maximum trigger input frequency 10 kHz

Interface and connectors

Sync Out for synchronization with following devices 1 Lemo connector

Trigger In for synchronization with preceding devices 1 Lemo connector

Analog Out for analog channels 8 Lemo connectors

Interface (connection to computer) USB 2.0 High Speed

Filter Amplifier

Number of amplifier 8

Input voltage range ± 500 mV

Input impedance

 parallel to 10 pF

>10

Input noise < 1 μV RMS (full bandwidth, inputs short circuited)

Noise density en = 9 nV / rout Hz

Appendix

Output voltage range ± 5 V

Output current 10 mA

Bandwidth 1 Hz to 2200 Hz

Gain options 100, 200, 500 or 1000

MC_Stimulus program

MC_Stimulus II Version 3.4.0 and higher

Operating system Microsoft Windows ® 7, XP or Vista with NTFS

English and German versions supported

Data import and export ASCII file format

STG3008-FA Manual

13.2 Pin Layout

Pin layout of the STG3008-FA Amplifier

Pin 1 to 8 Electrode IN 1 to 8 and Stimulus OUT 1 to 8 (+U / +I)

Stimulus Out and Electrode IN

Pin 9 to 13 Not connected

Pin 14 Ground (GND)

The STG3008-FA can software controlled toggle between recording and stimulation mode on pins 1 to 8.

Pin 14 connected to ground

Internal switch positions during stimulation and recording

13.3 Contact Information

Local retailer

Please see the list of official MCS distributors on the MCS web site.

User forum

The Multi Channel Systems User Forum provides the opportunity for you to exchange your experience or thoughts with other users worldwide.

Mailing list

If you have subscribed to the mailing list you will be automatically informed about new software releases, upcoming events, and other news on the product line. You can subscribe to the list on the contact form of the MCS web site.

Appendix

www.multichannelsystems.com

14 Index

STG3008-FA Manual

About dialog 49

Adjusting

Stimulus Intensity Level ....................30

Amplifier

blanking.............................................53

connecting...................................60, 62

Amplitude

adjusting stimulus intensity level.....30

effects on rise time ...........................63

of sine wave ......................................18

Analog

current output...................................62

input ....................................................7

voltage output ..................................60

Arrange Icons 49

ASCII

Import without Header ....................34

importing ASCII files .........................33

supported file format .......................34

Assign

channels to Auto Sync ......................29

trigger to channels............................55

trigger to Sync Outs..........................55

Auto Download

stimulus intensity level .....................30

Autocalibration 11

disable................................................11

Autocreating

stimuli ................................................23

Autofill 23

Autorepeat

pulses or complete pulse protocols .20

Cascade 49

Change All

stimulus intensity level..................... 30

Change Time Unit 23

Channels

connecting ..........................................7

displaying ..........................................43

downloading..................................... 47

editing ...............................................17

Compiler warnings 52

Connecting

the STG to an amplifier...................... 7

Contact

information....................................... 87

Continuous

stimulation ........................................20

Copy

row..................................................... 50

shortcut key ......................................50

Count 23

Creating

Autosync pulses ................................29

Stimuli ............................................... 17

Current

capacitive behavior of electrodes.... 77

electrode impedance........................ 63

maximum output current ..........62, 84

oscilloscope ....................................... 62

output mode.........................17, 59, 62

resolution ..........................................18

Cursor 44

Cut

rows ...................................................50

shortcut key ......................................50

Back panel 7

Batch

menu..................................................49

mode..................................................57

Batch Mode 57

Biphasic pulse 18, 77

Blanking

amplifier ............................................53

autocreating blanking pulses...........29

signal..................................................53

BNC

connectors ...........................................7

Cables

shielding ......................................60, 62

twisted pair .......................................60

Capacitive

behavior of electrodes......................77

Data

ASCII file format ...............................34

download ..........................................47

save.................................................... 51

Digital

blanking signal .................................53

input ..............................................7, 53

output ...........................................7, 53

port...................................................... 7

Display

Auto Sync output.............................. 29

scrolling .............................................44

selecting channels............................. 43

settings ..............................................43

zooming ............................................ 44

Downloading

batch mode ....................................... 57

shortcut key ......................................50

stimulus files .....................................47

Driver

STG3008-FA Manual

installation...........................................9

Duration

pulse...................................................18

Edit

Auto Sync Settings ............................29

menu..................................................49

Trigger Settings.................................55

Electrode

capacitive behavior...........................77

End

point of ramp ....................................18

run......................................................11

Error Messages 80

Faraday cage

connecting...................................60, 62

File

Batch mode .......................................57

importing ASCII files .........................33

menu..................................................49

new ....................................................50

open...................................................50

save ....................................................50

Format

ASCII file ............................................34

time axis.............................................43

Gain settings 13

GND outputs

about .................................................59

connecting...................................60, 62

Ground

connecting...................................60, 62

input ....................................................7

outputs ..............................................59

Group

Group Repeat ....................................20

Group/Ungroup.................................20

H 13

Header

of ASCII file........................................34

Help

menu..................................................49

HL 13

I outputs

about ...........................................59, 62

Icons

arrange ..............................................49

Ignore

trigger events if channels still active55

Importing

ASCII files........................................... 33

supported ASCII file format .............34

Incrementing

values in a column ............................ 23

Input

analog .................................................7

MC_Card.............................................. 7

MEA1060 .............................................7

trigger settings .................................55

TTL .....................................................53

Installing

Software.............................................. 9

STG driver............................................ 9

Inverting

pulses................................................. 23

selection ............................................ 23

Keep Zero 23

L 13

Length

of pulse.............................................. 18

Load resistance

effects on rise time........................... 63

ASCII files........................................... 33

files in Batch mode........................... 57

MC_Card

connecting ..........................................7

MEA1060

connecting ..........................................7

Measure tool 44

Message boxes

warning messages ............................52

Monophasic pulse 77

Multiple STGs

controlling......................................... 11

Operating.......................................... 15

New File 50

Open

ASCII files........................................... 33

file...................................................... 50

shortcut key ......................................50

stimulus files .....................................51

Oscilloscope

comparing STG current signals ........ 71

measuring current signals................ 62

measuring STG signals ......................60

Output

analog output signals.......................59

autocreating Sync Out pulses...........29

doubling amplitude..........................60

mode..................................................17

signal inversion ...........................60, 62

Sync Out settings...............................55

Panel

rear panel ............................................7

Paste

rows ...................................................50

shortcut key.......................................50

Period

of sine wave ......................................18

Port

digital...................................................7

serial.....................................................7

USB.......................................................7

Post Time 29

Pre Time 29

preview ..............................................51

printing worksheet ...........................51

setup ..................................................51

shortcut key.......................................50

Pulse

Autocreating Sync Out pulses ..........29

duration.............................................18

length ................................................18

types...................................................18

Ramp

pulse type ..........................................18

Rear panel 7

Rectangular

pulse type ..........................................18

Repeating

a group of rows.................................20

continuously ......................................20

on a trigger .......................................20

pulses .................................................20

rows ...................................................20

Requirements

system ..................................................9

Reset

display................................................44

STG .....................................................49

Reset All

stimulus intensity level .....................30

Resolution

current ...............................................18

time....................................................18

voltage...............................................18

Index

Restart

channels on a trigger .......................55

Rise Time 63

Rising edge

of TTL signal...................................... 53

time offset (Auto Sync) ....................29

Row Repeat 20

Run

STG..................................................... 11

Save

file...................................................... 50

shortcut key ......................................50

stimulus files .....................................51

trigger settings .................................55

Scrolling 44

Select Device 11

change............................................... 11

multiple .............................................11

Serial port 7

Settings

Auto Sync ..........................................29

menu .................................................49

Sync Out ............................................ 55

trigger ...............................................55

shielding

cables........................................... 60, 62

Shifting

values................................................. 23

Show

Auto Sync output.............................. 29

measure tool ..................................... 44

Signal

blanking ............................................ 53

current mode .................................... 62

menu .................................................49

Sync Out ............................................ 53

voltage mode.................................... 60

Sine wave

pulse type.......................................... 18

Single Trigger 55

Size to fit 44

Software

installation .......................................... 9

requirements....................................... 9

Start

channels on trigger ..........................55

shortcut key ......................................50

STG..................................................... 11

Starting

point of ramp.................................... 18

STG

connecting ..........................................7

installing.............................................. 9

menu .................................................49

STG3008-FA Manual

starting ........................................11, 53

Stimuli

creating..............................................17

Stimulus Files

ASCII Import without Header...........34

downloading .....................................47

Stimulus Intensity Level

Adjusting ...........................................30

Stop

Batch menu .......................................57

channels on a trigger........................55

shortcut key.......................................50

STG .....................................................50

stopping STG .....................................11

Support 79

Sweep

LED Start/Stop buttons .....................11

starting STG on trigger.....................11

status lamp ........................................53

sweep count ......................................55

triggering ..........................................55

triggering sweeps .............................53

Switch

circuit diagram ..................................53

Sync Out

autocreating Sync Out pulses...........29

connectors ...........................................7

digital TTL outputs............................53

settings ..............................................55

System requirements 9

Tile 49

Time

axis format.........................................43

change time units .............................23

resolution ..........................................18

rise time .............................................63

time offset for Auto Sync .................29

Timing

blanking of amplifier........................53

rise time .............................................63

Toolbar

position..............................................49

Trigger

blanking signal..................................53

connectors ...........................................7

continuous mode ........................20, 55

gate..............................................20, 55

gating trigger..............................20, 55

input ..................................................53

LED Start/Stop Button ......................11

manual ..............................................11

output ...............................................53

repeating pulses ...............................20

separate............................................. 11

settings ..............................................55

single trigger..................................... 55

STG............................................... 11, 53

triggering multiple files on same

trigger (Batch mode)........................ 57

Troubleshooting 79

TTL

autocreating Sync Out pulses .......... 29

blanking signal .................................53

digital output.................................... 53

Sync Out settings .............................. 55

trigger settings .................................55

triggering ..........................................53

twisted pair cables 60

U outputs

about ...........................................59, 60

oscilloscope ....................................... 60

voltage mode.................................... 60

Undo

shortcut key ......................................50

Update

software .............................................. 9

USB connector 7

USB-MEA32-STIM4-System 15

Select Stimulation Channels ............ 15

View

menu .................................................49

Voltage

maximum output........................ 60, 84

output mode.........................17, 59, 60

resolution ..........................................18

Warning messages

disabling............................................ 47

Window

menu .................................................49

WYSIWYG window..................... 43, 44

Zooming 44

Multichannel Systems STG3008-FA User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual