Configuring m-pod’s Pin Assignments

Summary

The signal mapping feature in m-pod allows you to configure pin assignments to suit your research. This feature is best explained using examples. Assuming you are using an EEG device that accepts 8 bits of input:

In one experiment, it may be important to know which key the participant has pressed. If using a five key RB-540 response pad, you can map each key to a separate output line. This leaves three lines for other signals, e.g. one for the light sensor and two for event markers sent via USB.
In another experiment, you need a lot more output lines dedicated to event markers sent via USB. But it would still be helpful to know when a key, any key, was pressed. In this scenario, you can map ALL the response pad keys to a single output line, thus leaving you with seven bits for USB event markers.

The Xidon utility lets you do all these things quite easily. The rest of this page assumes that it is already installed.

The Steps

The screenshots and steps below assume that you are using an “m-pod for Parallel Port” that is connected to StimTracker; the steps are similar for when m-pod is connected to an RB or Lumina 3G controller.

On your Mac or Windows computer, launch Xidon.
in Xidon, click on the Search for Device button. Once Xidon finds StimTracker, it will display the correct model and the names of all the m-pods that are attached to it.
Click on the Device menu → m-pod for Parallel Port → Signal Mapping….

IMPORTANT NOTE

When you choose Signal Mapping from the menus, the dialog that appears will allow you to edit m-pod’s internal “translation table”. It is important to realize that m-pod keeps internally two translation tables: one is used with StimTracker, the other is used with the RB-x40 response pads and Lumina fMRI response pads. When you make changes to the signal mapping of an m-pod that is connected to StimTracker, this does not affect m-pod’s signal mapping when it’s connected to a response pad.

In the list on the left side of the dialog, click to select the output line that you want to configure. The “Count” column tells you how many signals are assigned to that line.
On the right side of the dialog, enable the signals that you want m-pod to produce on that line.
Sometimes, a signal’s name is colored in red or purple. This is Xidon’s way of letting you know what the signal is not assigned to any output line or that it’s assigned to two or more output lines.

When done making your changes, click on the Preview Changes > button.
The Preview Changes panel shows you the same information, but in a textual form that can be copied to the clipboard and conveniently saved or shared with colleagues.
When ready, click on the Apply Changes button. The edits that you made will be saved to flash memory and will be remembered even after m-pod is powered off.