# Global Variables Global variables are values that can be substituted to the usual number on every Weight, Offset, Differential or Expo setting. Their main use is to group the adjustment of several parameters that should have the same value. For example, aileron differential on a glider with 4 surfaces responding to the aileron function. When trying to find the sweet spot for the differential value, instead of having to repeatedly edit the differential value in 4 mixers, all 4 can be set to use a global variable (e.g. GV1 resp. -GV1, selected by a LONG press of the ENTER key on the Differential field). Then adjusting GV1 on this page is all it takes for all differentials to be updated. Global variables are also flight mode specific, so instead of having to create separate mixer lines with different values depending on the flight mode one can simply use a global variable with different values for each flight mode. This can significantly help simplifying the mixer screen by avoiding many duplicate entries. Global variables can also be adjusted in flight thanks to the Adjust GVx Custom Function that will be described later, and help adjusting those parameters that are easier to tweak in flight like D/R ratios, expos or again differential. The Global variables screen allows setting a name for each of the 5 available variables for conveniency, and seeing/setting the value each of them will have in each of the 9 flight modes. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://doc.open-tx.org/manual-for-opentx-2-2/software-overview/model_menus/global_variables.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.