Calterm is an engineering tool; it does not have the same safety "guardrails" as consumer software like INSITE. An incorrect click or a corrupted calibration file upload can "brick" an ECM (render it useless). This results in a very expensive replacement bill.
While INSITE allows basic changes (like tire size or axle ratio), Calterm allows access to the "calibration" files. This enables users to adjust fueling parameters, injection timing, and speed limits. This is often used in performance tuning or adjusting engines for non-standard applications.
To use Calterm 5 in a "portable" capacity (meaning mobile diagnostics), you need the correct hardware setup: