This option is much more buggy than using a laptop, but it does work well once setup. I do not provide technical support for this method, so if you have trouble you will need to call SCT directly. I only provide support for the laptop datalogging methods. These instructions are directly from SCT for the Xcal2, but the procedure is nearly identical to the livewire and the xcal3. If you have comments or tips, please post them up! On Device Datalogging
Using The On Device Datalogging
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