TTL signal to biopac

[JEC]

Thanks.

As best I can gather, your Biopac unit has 8 digital I/O pins available.

Page 10 of this document

http://www.biopac.com/Manuals/bsl%20...re%20guide.pdf

Shows that Digital Input #1 of the IO port connector corresponds to Pin #10.

The cable you're using shows that Pin 10 of the Biopac system is connected to Pin 2 of the parallel port:

http://www.biopac.com/Education.asp?Pid=4653&lower=1

Pin 2 of the parallel port corresponds to Bit 0 of an 8-bit data byte.

http://beyondlogic.org/spp/parallel.htm

I assume that you're hoping to send a signal from MediaLab to the Biopac system when specific pictures or stimuli are displayed on screen. Is that correct?

Assuming it is, here's what you need to do.

Note that I'm following the template shown here:

http://empirisoft.com/support/showth...&highlight=TTL

For a .5 second (500 mS) output pulse duration on Port 888 (0x378), the syntax is

(d5<1,888,500>)

This turns on only bit 0, which corresponds to a binary byte %00000001 or a decimal number 1. 'On' duration is 500 mS.

Does that make sense?

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Both DirectRT and MediaLab also come with a TTL testing utility called 'IOTest.' It can send and receive signals from the parallel port and is handy for testing. It's located in the 'utility' folder of each software installation.