# CVPORT System Variable [GstarCAD 2021](Help%20System/GSTARCAD/2021/Index.md) → [System Variables](Help%20System/GSTARCAD/2021/System%20Variables/(System%20Variables).md) → [C](Help%20System/GSTARCAD/2021/System%20Variables/C/(C).md) ## Function Description: The CVPORT system variable is used to change identification code in current viewport. | | | | --- | --- | | Type | Integer | | Saved in | Drawing | | Initial value | 2 | ## System Variable Value: Users could change current viewport by setting the CVPORT system variable, first they should meet the following conditions: 1\. The specified identification code should be one active viewport code. 2\. The cursor has not been locked and it could move to viewport when executing a command. 3\. The Tablet mode has turned off. --- ## Other versions with matching text [GstarCAD 2016](../../../2016/System%20Variables/C/CVPORT%20System%20Variable.md) · [GstarCAD 2017](Help%20System/GSTARCAD/2017/System%20Variables/C/CVPORT%20System%20Variable.md) · [GstarCAD 2018](Help%20System/GSTARCAD/2018/System%20Variables/C/CVPORT%20System%20Variable.md) · [GstarCAD 2019](Help%20System/GSTARCAD/2019/System%20Variables/C/CVPORT%20System%20Variable.md) · [GstarCAD 2020](Help%20System/GSTARCAD/2020/System%20Variables/C/CVPORT%20System%20Variable.md)