# SDI System Variable [GstarCAD 2020](Help%20System/GSTARCAD/2020/Index.md) → [System Variables](Help%20System/GSTARCAD/2020/System%20Variables/(System%20Variables).md) → [S](Help%20System/GSTARCAD/2020/System%20Variables/S/(S).md) ## Function Description: The SDI system variable is used to control the program running on single file interface or multiple file interface. | | | | --- | --- | | Type | Integer | | Saved in | Registry | | Initial value | 0 | | Range | 0 \~ 3 | ## System Variable Value: **0:** open multiple drawing interface. **1:** close drawing interface. **2:** （Read-only）suppress multiple drawing interface,because the application which does not support multiple drawing mode has been loaded. SDI was set 2 as not saving. **3:** （Read-only）suppress multiple drawing interface,because SDI was set 1 and the application which does not support multiple drawing mode has been loaded. SDI was set 3 as not saving. If SDI was set 3, ICAD will reset as 1 after unloading the application which does not support multiple drawing mode. --- ## Other versions with matching text [GstarCAD 2016](../../../2016/System%20Variables/S/SDI%20System%20Variable.md) · [GstarCAD 2017](Help%20System/GSTARCAD/2017/System%20Variables/S/SDI%20System%20Variable.md) · [GstarCAD 2018](Help%20System/GSTARCAD/2018/System%20Variables/S/SDI%20System%20Variable.md) · [GstarCAD 2019](Help%20System/GSTARCAD/2019/System%20Variables/S/SDI%20System%20Variable.md) · [GstarCAD 2021](Help%20System/GSTARCAD/2021/System%20Variables/S/SDI%20System%20Variable.md)