It seems you’re referencing , possibly with a number 21 (which could be a software version, module ID, error code, or internal reference), and “deep text” — likely meaning you want a detailed, technical explanation.

One of the software's strongest selling points is its fidelity to real controllers. The software does not use a generic, simplified interface. Instead, it offers emulations of industry-standard controls, most notably and Siemens (specifically the Siemens 840D sl and Fanuc 0i-TF/31i). For a student, this means the muscle memory developed while clicking through the software’s interface translates directly to the shop floor. The keyboard shortcuts, menu navigation, and display readouts mirror the physical counterparts.

Version 5.1 introduces a refined workspace that prioritizes screen real estate. The interface is split into logical segments:

are available to guide users through geometry modes and work plan creation. SYMplus™ for CNC training - SYMplus™ by KELLER.Software