Electronic trip unit capable of analog and digital setting of circuit breaker setpoints

A trip unit is provided with a microcontroller and non-volatile memory, such as EEPROM (Electrically Erasable Programmable Read Only Memory) or Flash memory, for storing trip setting values, including initializing parameters, boot code, and operational parameters being capable of analog or digital programming depending on a switching instruction. This configuration enables one to change the trip unit's trip setting values after it is manufactured either remotely or locally. The present invention provides thus increased functionality to trip units by enabling upgrades and servicing of the trip unit by downloading replacement trip setting values to it and having multiple operational parameters (trip setting values) available. This would include locally altering trip setting values and remotely downloading trip setting values when the electronic trip unit is connected to a host controller, such as a multi-purpose computer either directly, over the telephone lines, LAN or any other suitable connection such as the Internet.