Summary

PowerLab 15T

PowerLab 4/20  (discontinued)

PowerLab 4/20T  (discontinued)

PowerLab 4/25  (discontinued)

PowerLab 4/25T  (discontinued)

PowerLab 2/26

PowerLab 4/26

PowerLab models 200, 400, 800, 10T, 4S, 8S, and 16S  (discontinued)

These models do not have a Digital Input connector.

Default Output Signals

Digital Input No.

Decimal Value

For

1

1

USB bit 0

Key press 1

OR

2

2

USB bit 1

Key press 2

OR

3

4

USB bit 2

Key press 3

OR

4

8

USB bit 3

Key press 4

OR

5

16

USB bit 4

Key press 5

OR

6

32

USB bit 5

Key press 6

OR

7

64

USB bit 6

Key press 7

OR

8

128

USB bit 7

Key press 8

Light sensor

OR

OR

Digital Input No.

Decimal Value

For

Notes

1

1

USB bit 0

Light sensor 4

Quad model only

OR

2

2

USB bit 1

Light sensor 3

Quad model only

OR

3

4

USB bit 2

Light sensor 2

OR

4

8

USB bit 3

Voice key / mic

Quad model only

OR

5

16

USB bit 4

Any participant key press

OR

6

32

USB bit 5

Audio – left

OR

7

64

USB bit 6

Audio – right

OR

8

128

USB bit 7

Light sensor 1

OR

Customizing The Output Signals

m-pod contains a powerful microprocessor that can reassign any input signal to any output line, and without any significant delay. It can also assign multiple signals to the same output line.

The tables above describe the factory default. If your experiment or lab setup requires different output, Cedrus provides a free utility for configuring your m-pod. After you use it, your configuration is saved to flash memory so that it’s remembered even you power off m-pod.

Deciding on How to Setup LabChart

The LabChart feature that you need is called “preset comments”. It offers a few different ways to record external triggers, but only two are relevant to using m-pod. One method is called digital bit and the other is digital byte:

• Digital bit: An example is when you want to describe a trial, e.g. congruent vs. incongruent. You would need just two “digital bit” preset comments that use different input lines, e.g. lines 1 and 2.
• Digital byte: An example is where you want to note the color of the text being presented and have 15 different colors. Only 8 bits are available to you, but with the digital byte feature, you can use the combinations of only 4 bits. You will need to create 15 digital byte preset comments for all the combinations.

Note that you can use digital bits and digital bytes in the same experiment. You can describe the congruency of a trial using two input bits and note the color on another four bits — and you still have two extra bits available. We will use the two examples above to provide step-by-step instructions next.

Setting Up LabChart – Using Digital Bits

Let’s setup two preset comments to describe a trial’s congruency. We will use digital bits 7 and 8.

These instructions apply to LabChart version 8.1.5; they will also work with earlier versions of LabChart for Windows, but you will need version 8.1.5 or later of LabChart for Mac.

1.

Click on the Setup menu and choose Preset Comments….

2.

3.

The Preset Comments dialog appears. Click on the New… button; an Event Configuration dialog appears.

Let’s setup a preset comment for trial condition “Congruent” by choosing the Digital bit radio button. Click button “7” to select digital bit 7, shown circled in the screen snapshot below. The bars about the buttons are “live”: they will light up in green when input is detected, providing real-time feedback.

4.

Give this preset comment a name, e.g. “Congruent”.

Setting Up LabChart – Using Digital Bytes

Now let’s setup preset comments to describe the color of the text being presented. We will use digital bits 1, 2, 3 and 4, the combination of which will allow us to provide 15 different values.

1.

As before, click on the Setup menu and choose Preset Comments…. When the Preset Comments dialog appears, click on the New… button to bring up the Event Configuration dialog.

2.

Select the Digital byte radio button.

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Last Revision: July 3, 2018