Dear Cedrus Support,

I generate task by using superlab 4.5 and I use response pad 834 for participant’s response.I use Acqknowledge software (Biopac) for acquisition and analysis.Because of I will study ERPs, so I use Stim tracker for generate event marker. I connect StimTracker to Biopac via STP1100 c.
I perform all of these by using Cedrus & Biopac Guide and Manual but Superlab can not talk to Stimtracker and disappear marker in Acqknowledge software. I have already installed USB driver.
I need an event marker, that sends pulse to EEG recording device in difference condition (stimulus onset, participant’response and feedback) simutaneously.

Detail (what I want experiment to do)

  1. Display of four reference cards on the upper third of computer screen, plus one response card occupying center on the lower third of the screen.
  2. Participant will press response pad (RS834) for sorting.
  3. Auditory feedback is delivered 1600 ms after the response.
  4. Next trial ( 2 -3 sec after feedback)
    I created an event “Digital Output”, set it to “Generate a pulse” with a duration of 500 milliseconds, Inter-pulse interval 200 milliseconds and set repeat pulse to 1. Turn on all checkboxes labeied EM0 through EM7. I created event “Digital Output” 3 event for stimus onset, participant’s response and feedback.
    A complete task consists of two blocks with 18 series of 7 trial each) Semi random.

I am unsure whether I have created the experiment correctly and I am not sure If that is due to a mistake on my part or not.

Thank you,


This will be easiest answered over the telephone. I will contact you via private message to set up a time.

Create digital output in Superlab

Dear Cedrus support

Thank you so much for taking the time. I follow the Cedrus instructions to test the communication between the 3 devices (Superlab Computer - Stimtracker - EEG computer) and check if the markers are being sent. I create event digital output in Superlab software and set:

• Set “Pulse duration” to 500 milliseconds

• Set “Inter-pulse interval” to 200 milliseconds

• Set “Repeat pulse” to 10 times

• Turn on all the checkboxes labeled EM0 through EM7

I click on the Test Now button. The bule " marker" light on Stim Tracker’s front panel light up. Superlab is able to communicate with Stim Tracker and I also see event marker appear in ACQKnowledge software (Biopac).
I think, the 3 devices (Superlab Computer - Stimtracker - EEG computer) can communication.
When I run program superlab, I see event marker only in the first stimulus.I am not sure, I creat appropriate digital output in Superlab PC to MP unit.

Can you advice me how to create appropriate event digital output which send pulse simutaneously with stimulus presentation, participant’s response and feedback?

Thank you for your time and assistance that you could give me

Best regard,


Please see the sample experiment posted displaying how to send a digital output pulse.

Ladda.sl4 (4.48 KB)


Dear Cedrus Support,

Than you very much. It’s useful for me. I have a problem about how to mark EM block in digital output when I use Strim tracker (EM0- EM7). The example file that you sent to me, you turn on only checkblock labeled EM0 . In Cedrus Website (Using Strim Tracker with SuperLab, suggest to turn on all the checkboxes labeled EM0 through EM7.

Thank you for your kindness.


On our website when it suggests to turn on EM0-EM7, this is only to establish the existing connection. You should only be selecting the lines you need.


Dear Cedrus support,

I want to send digital output pulse simultaneously to the feedback (correct or incorrect) which display in the screen. How can I do?

Thank you

In the Event Editor, under Feedback, present two events for either a correct or incorrect response. One event will send the pulse out and the other will be the text or message. This will have a few milliseconds in delay.