how to trigger a stimulus on BIOPAC HSTM01 with Biopac Student Lab and e-Prime

[Elena Broggin]

Hi all,

Does anybody has experience of triggering an electrical stimulation on BIOPAC HSTM01 (with MP35 and BSLSTM) with e-Prime and Biopac Student Lab?

I have connected the devices as follow:

The e-Prime laptop is connected via parallel port cable to the MP35 that is connected via a serial port (port named "analog out") to the BSLST that is connected with the HSTM01 (via port named “Output” in the BSLST). 
The MP35 is also connected via USB cable to the laptop with Biopac Student Lab. 

The HSTM01 works if I keep the red button pressed and I send the trigger from the BSLSTM (pressing the manual test behind the box) or if I keep the red button pressed and I click on a virtual switch in the Biopac Student Lab screen. 

Is there not a way to trigger the stimulus on BIOPAC HSTM01 with an experiment in e-Prime. I have tried with task event but it does not work...

Many Thanks,

Elena

[David McFarlane]

Elena,

I have no experience with the equipment you describe, but I do have some
experience with generally sending output (e.g., triggers, markers,
codes, signals) from E-Prime to external equipment. So a few general
thoughts ...

First, make sure that your MP35 will really respond to whatever input
you have E-Prime going to. Disconnect the E-Prime computer from the
MP35, and supply a known good input to the MP35 from some other source
-- e.g., you can provide a 3 V or 4.5 V input just by using 2 or 3 1.5 V
batteries in series. (And make sure to test your cable!)

Once you have that working, move on to making sure that E-Prime actually
produces an output. So again, disconnect the E-Prime computer from the
MP35, and hook up your LPT port to a voltmeter or an oscilloscope (or
some LEDs if you are clever), using the same pins as for the MP35. For
improved troubleshooting, do *not* use your actual experiment program
for this work, instead make a separate test program just to explore how
to get E-Prime to produce outputs.

Along those lines, make sure that you have specified the correct LPT
port for E-Prime to use!

And make sure that your E-Prime program produces a "pulse", and one of
sufficient duration that the MP35 can detect it. E.g., add *two* Task
Events to your stimulus object: First one with Delay 0 to do a
WriteByte with your output signal, plus a second one with Delay 100 to
do a WriteByte back to 0.

I will be interested to learn if any of this helps, so please write back.

---------------
David McFarlane
E-Prime training online:
http://psychology.msu.edu/Workshops_Courses/eprime.aspx
Twitter: @EPrimeMaster (https://twitter.com/EPrimeMaster)