BioSemi USB trigger interface (for Presentation or E-prime)
 
Stimulus software such as Presentation need a parallel port for outputting its trigger signals, but most modern PC's and Laptops do not have a parallel port output anymore. Using a standard USB to parallel port converter cable does not work, because these converter cables are not detected correctly by the Presentation software. The BioSemi USB Trigger Interface is not detected as a parallel port, but it is detected as a serial port.
On the below screen shot the Parallel port is shown as the green trace and the BioSemi USB Trigger Interface is displayed as the yellow trace.
The delay of the BioSemi USB Trigger Interface (compared to the parallel port) is less than 200uSeconds. The jitter is less than 100uSeconds. Every value written to the USB Trigger Interface will be available at the USB Trigger Interface output for 8mS.

If you want to control the USB Trigger Interface through MatLab then you can find the documentation on how to control a serial port from MatLab here: https://nl.mathworks.com/help/matlab/ref/serial.html

The BioSemi USB Trigger Interface is able to output 8 parallel bits and interfaces direct to the BioSemi USB Receiver trigger input/output connector.
 
Ordercode: USB Trigger Interface
Price: 100 Euro
The trigger interface is recognized by the PC as a serial Com-port.
You can connect to the trigger interface with the following settings:
Data Rate: 115200
Data Bits: 8
Stop Bits: 1
Parity: none
Flow Control: off
After a data Byte has been sent to the serial port of the USB Trigger Interface, the pins of the USB Trigger Interface will respond immediately and will hold this value for 8mS. After 8mS, all pins will be reset to zero.
 
 
 
 
USB Trigger Interface connections (37 pins male Sub-D)
 
Pin01
Trigger output 1
Pin02
Trigger output 2
Pin03
Trigger output 3
Pin04
Trigger output 4
Pin05
Trigger output 5
Pin06
Trigger output 6
Pin07
Trigger output 7
Pin08
Trigger output 8
Pin09
 
Pin10
 
Pin11
 
Pin12
 
Pin13
 
Pin14
 
Pin15
 
Pin16
 
Pin17
 
Pin18
 
Pin19
 
Pin20
 
Pin21
 
Pin22
 
Pin23
 
Pin24
 
Pin25
 
Pin26
 
Pin27
 
Pin28
 
Pin29
 
Pin30
 
Pin31
 
Pin32
 
Pin33
Pin34
Pin35
Pin36
Pin37
Ground

 

 

 

When sending triggers from E-Prime, then add a Serial device and set the appropriate settings: COM number, Baud Rate, etc.
To send the triggers, use Task Events, Configure Task Events, How to Task Events.
Because all pins of the USB Trigger Interface are reset after 8mSec, you do not need to clear the port before sending a new trigger.

 

In the case that you want to easily/quickly test if your BioSemi USB Trigger Interface is working correctly, then you can do this by using the small Terminal test program called "Putty"

Connect the USB Trigger Interface with a USB cable to your PC.
Connect the USB Trigger Interface to the BioSemi USB Receiver.
Install Putty, and run Putty.
At "Connection type" enter: Serial.
At "Speed" enter: 115200.
At "Serial Line" enter the COM port at which the USB Trigger Interface is located.
You can find the COM port at which the USB Trigger Interface is installed in the Windows Device Manager. The below screenshot shows the settings for a USB Trigger Interface installed at COM5.
Now open the Putty terminal bij clicking on "Open"
Run ActiView and start the data acquisition. Now select the Putty window and press random keys on the keyboard. These key codes will appear as triggers in ActiView. See the screenshot below.