StimTracker outputs

Hello, I am wondering if you can help me. Is it possible to set up SuperLab to use the StimTacker’s TTL output (from the DB25 extra port) to allow event trigger outputs to be detected by external equipment?

Thank you

Natalie

This is most likely very possible, but I do need more information. What external equipment do you want to connect to?

Trigger outputs

We are connecting to an external eeg system to provide event trigger information in the recordings. We already have something that connects to the extra port.

All the output pin assignments are described on the following webpage:http://www.cedrus.com/support/stimtracker/tn1460_st100_pins.htm

You should be able to build the cable you need from the information listed.

Thank you

This is the response I had from our EEG specialist…might be helpful to you.

I had already seen this before and we built the cabe based on the TTL output lines on the Extra Port. The problem came when we tried to get the SuperLab software to do something with these ports; i.e. toggling the state of one of the TTL output lines when an event occurs. This is what we need for the EEG system.

When you send event markers from SuperLab to StimTracker (using Digital Output Event Type) the lines that are effected on the extra port connector are the “Event marker bits” not the TTL output line.

“Yes, this is how I understood the Digital Output Event Type to work; i.e. manipulating the event marker bits. In that case though, what (if anything) can be used to control the TTL Output line on the StimTracker?”

The TTL output line conveys the same information that the StimTracker receives on its TTL input connector. This is typically used for marking the onset of a participant’s response, as that connector happens to be compatible with the Accessory Connector found on our Response Pads and SV-1.

coding event markers

I am trying to create unique event marker codes to send to BrainProducts Visualizer. I seem to be limited to a small number of code numbers. I thought iwould be able to enter numbers from 1 to 255 (Events Editor), so theoretically 255 different codes. But at a certain point the numerical codes star repeating as markers on the Visualiser, which causes confusion becase different markers have the same code. How many unique numbers can be created?

Also, at the moment, my RB 530 box sends blue coloured ‘R’ prefixed markers to the EEG for three of the buttons, but for the fourth button (bottom) the code being send is red S. How can I fix this. It should be a blue R to mark a response.

Thanks in advance if you can help

Steve

For BrainProducts there are only 5 event maker lines. For more information, please see the following link: http://www.cedrus.com/support/stimtracker/tn1463_brainamp.htm

Regarding the blue colored “R” and red “S”, I don’t know what this is. Can you post a picture/screen-snapshot?

stimtracker and BrainProducts EEG

Thanks for the info.

So with 5 bits, how many unique number codes can be generated in total? At the moment I can only define 16 unique numbers for stimulus onset markers. IE, in the event editor, in the box that says 'or enter a number from 1 to 255, after i have defined from 1 to 16, the 17th marker repeats one of the first 16. I would think there should be more available but don’t know how to create them.

The red and blue colour codings are event markers sent to the EEG. For events that mark stimulus onset (coming from Superlab) the events are marked with a red S (plus a number generated by the bit combinations, as mentioned above), and the blue markers come from the button box (Rb530). This red-blue coding works fine and consistently for all stimuli and buttons except the bottom button – ie when you press the bottom button, the marker sent to the EEG is a red S, whereas for all other buttons the marker is a blue R. I want to make all responses blue Rs and all stimuli red, but I can’t see how to do this in superlab or in the Brain Recorder software.

If that still does not make sense I will send a screen shot of the brain recorder interface.

With 5 bits you can get 31 different combinations. Are you taking advantage of the other StimTracker features? For example, using the light sensor feature to measure the onset of the visual stimulus. Or, using the TTL input to have SuperLab automatically mark the onset of the participant input?