Hi, I'm a developer on the SimBiology team. I'm not sure I fully understand your question, but I'll try to answer based on my current understand. However, since you mention that this query is urgent, I also want to mention that MATLAB Answers is may not the best venue for urgent questions. You may prefer to directly contact MathWorks, so that an experienced engineer can work cirectly with you to answer your questions. You can find options for that here.
You can find more information about unit conversion on this reference page. Unit conversion applies to all quantities in your model, not just time. When you enable unit conversion in SimBiology, you must add unit information to all quantities in your model. Then, when you write expressions, SimBiology will ensure that your expression is dimensionally consistent and perform all the appropriate unit conversions to perform. For example, let's say you have an assignment rule "x = y + z", x has units of mole, y has units of millimole, and z has units of micromole. SimBiology can see that all three quantities have the same dimensions of amount, and so the rule expression is dimensionally consistent. Then, it will internally convert everything to consistent units before performing the addition, but all values will be reported back to you in the units you specify.
I'm not sure what you mean by global units. You can specify whatever units you want on the model. Perhaps you are asking what units SimBiology uses internally when simulating the model. If so, those are implementation details that we don't generally provide to users, becaue for the most part they shouldn't affect the user's results. This allows us to change the implementation as needed for future enhancements. That said, we do document a couple a few aspects of the internal units used during simulation. If you look at this page, you will see the options AmountUnits, MassUnits, and TimeUnits. These options can be used to control the internal amount, mass, and time units used by SimBiology. If you need more details, I can provide them. But I would need to understand your question better to provide an appropriate answer. What information do you need and why do you need it?
As for your final question, the person who creates the SimBiology model determines the names of parameters. You can then reference parameters by names wherever you need to reference their values.
I also recommend you take a look at the SimBiology documentation. In particular, you may find wnat to look at the Getting Started section and the Examples (many of which use unit conversion).
