Writing a VTS communication driver involves developing all components that are essential to the software including common driver drawing methods, error checking, and collection of statistics.
Since VTS communication drivers are tags, their code must meet all of VTS's requirements for a tag, as well as the requirements for a driver. The rules for all custom tag types are included elsewhere in the Programmer’s Guide. See: Tag Template Module Rules.
Older drivers often used two module files: one for the high level tasks that interfaced between the I/O tag and the VTSDriver module and one for the lower level tasks that were specific to the driver protocol. This model is obsolete. It is recommended that communication drivers be created within a single file.