A number of different coordinate systems for graphics, electrical engineering, fluid power, and process engineering are available in EPLAN. The coordinate system depends on the page type; however, you can temporarily switch to a different coordinate system if necessary (in the Coordinate input dialog). Internally, all coordinate systems have their origin at the lower left-hand corner of the drawing area.
Graphical coordinate system
The graphical coordinate system has its origin on the bottom left. The coordinate entries are relative to the point of origin. Coordinate values are entered in the unit "mm".
The coordinates are displayed as X / Y in the status bar.
Logical coordinate system for electrical engineering
The electrical engineering coordinate system has its origin in the upper left corner of the drawing area. The coordinate entries relate to the "uppermost schematic position" and the defined grid size, i.e., coordinate values are specified in grid increments (default grid increment: 1, grid unit = 4 mm).
The coordinates are displayed as RX / RY in the status bar.
The entry of the uppermost schematic item specifies where the logical zero point (for the electrical engineering coordinate system) lies. This setting is made in the plot frame, and the highest possible position is given there. Since the logical grid is always oriented to the internal coordinate origin (0.0 bottom left), the entry of the uppermost circuit diagram item is only an approximate value, which is rounded to the nearest grid unit.
Logical coordinate systems for fluid power and process engineering
The fluid power and process engineering coordinate systems have their origin at the bottom left. The coordinate entries relate to the origin and the defined grid size, i.e., coordinate values are specified in grid increments.
The coordinates are displayed as RX / RY in the status bar.
When enlarging a page by converting to a different page format (e.g., from DIN A3 to DIN A2), the page area is extended upwards and to the right. This means that no negative coordinates must be used. Macros, etc., are placed at the lower left of the larger page.
3D coordinates system
All 3 axes in the coordinates system are visible in the isometric view of the layout space. The axes are distinguished by their color:
- X-axis: red
- Y-axis: green
- Z-axis: blue
Moving base points
The Base point shift function allows you to define an optional coordinate base point. The new base point is displayed with a small coordinate cross. In the status bar, the display of the coordinates changes from X / Y to DX / DY (graphical coordinate system) or from RX / RY to DRX / DRY (logical coordinate system), and the values are displayed relative to the new base point.
The relative input of coordinates when drawing graphical objects is always relative to the last point placed. This must not necessarily be a point in the graphical object; it can also be the new coordinate base point! Thus, if you insert the first line point, for instance, when drawing a line, then set a coordinate base point, the relative coordinates will be relative to the coordinate base point and not on the line point you inserted earlier.
See also
Moving the Coordinate Base Point