I want to create some software that links with the Polaris Timer and have not been able to find how the data is transmitted to the computer. I know you have to have the cable but how do I access the data via software?

You can use a languaje like Visual Basic to detect the input string for device maybe.

Visual basic has "comm" control, you can see examples by google.com searching with "visual basic ports" or "visual basic code comm control"