What is the difference between programming track and programming on main?

Programming track is normally used for safer setup and decoder reading. It uses the dedicated programming output and is the usual place to read CVs or set a new decoder address.

Programming on main writes changes to a decoder on the main track. It is useful for quick adjustments but usually cannot read CV values back. Be careful with programming on main because the target address must be correct.

Imported from: DCC-EX CSB1 and Engine Driver FAQs