The USB stick based configuration feature allows preparing a USB stick that contains one, multiple or all configuration parameters for a charge controller. The stick is placed into a charge controller. The charge controller detects the configuration changes, applies them and reboots the charge controller to make the changes take effect.
It is possible to apply only one or a subset of the possible configuration parameters to a charge controller. This way one USB stick could contain all the parameters relevant for the hardware settings. Another USB stick could contain customer specific settings that are independent from the hardware. Yet another one could turn on or off the freecharging option. A charge controller could then easily be configured by applying multiple USB sticks after another.
To ensure that a person with access to the USB port of the charge controller actually is authorized to make configuration changes, the USB stick needs to contain a file named USB_PASSWORD in the root folder that contains either the operator or manufacturer password. If such a file does not exist, no configuration changes are applied.
In addition the USB stick should contain a folder named sw_config in the root folder. This folder should contain the files with the parameter changes to be applied.
The easiest way to obtain these parameter files is by using another USB stick with the file FIELD_ENGINEER as well as the USB_PASSWORD file in the root folder and placing this into a charge controller that has already been configured manually with the correct settings. When the stick is inserted the charge controller will copy its full configuration along with log files onto the stick. The parameters to be applied to other charge controllers with the USB stick can then easily be copied into the folder sw_config of the configuration stick.
When the stick is inserted the controller will signal by blinking with all front LEDs that the configuration is being applied. After applying the parameter changes the controller will reboot automatically. After the reboot when no further changes can be applied from the stick, the controller will signal that by blinking quickly with the ready LED.
This parameter allows disabling this feature. If disabled, no configuration changes are accepted via USB even if the correct password file is present.