Context: 
The figure below shows an example of creating a rectangular datum coordinate
  system defined by three points. 
 
  

When 
  Abaqus/CAE
  prompts you to select a point, you can select the origin of a datum coordinate
  system. When 
  Abaqus/CAE
  prompts you to select an edge, you can select one of the axes of a datum
  coordinate system. 
 
  
	 From the main menu bar, select
		.
	 
	 
The Create Datum dialog box appears. The dialog
		box outlines the types of datum geometry you can create.
	 
	 Abaqus/CAE displays prompts in the prompt area to guide you through the procedure.
	 
	 
		
	 
   
  
	 From the list of types at the top of the dialog box, choose
		CSYS.
	 
	 
The Method list indicates the methods you can
		use to create a datum coordinate system.
	 
   
  
	 From the Method list, select 3
		points.
	 
	 
Abaqus/CAE
		displays the Create Datum CSYS dialog box.
	 
   
  
	 From the dialog box, enter the name of the datum coordinate system. 
	 
	 
To help keep track of your datum coordinate systems, 
		Abaqus/CAE
		displays its name in the 
		Model Tree.
		In addition, you can use the 
		Model Tree
		to rename the datum coordinate system. 
	 
   
  
	 From the dialog box, select one of the following datum coordinate
		systems:
	 
	 
		
 
		  -  
			 
Rectangular: The
				X-, Y-, and
				Z-axes are aligned with the 1-, 2-, and 3-global
				axes, respectively.
			 
 
		   
 
		  -  
			 
Cylindrical: The
				R-, -,
				and Z-axes are aligned with the 1-, 2-, and 3-global
				axes, respectively.
			 
 
		   
 
		  -  
			 
Spherical: The
				R-, -,
				and -axes
				are aligned with the 1-, 2-, and 3-global axes, respectively.
			 
 
		   
 
		
	 
   
  
	 From the Create Datum CSYS dialog box, click
		Continue.
	 
	 
Abaqus/CAE
		displays a default datum coordinate system. The origin of the datum coordinate
		system is located at the origin of the part or assembly. In addition, the axes
		of the default datum coordinate system are aligned with the coordinate system
		of the part or assembly.
	 
   
   
	 If desired, select Make Independent from the
		prompt area to create the datum as an independent feature. 
	  
  
 
 
  
	  If you want to accept the default datum coordinate system, click
		Create Datum from the prompt area. 
	 
	 
Abaqus/CAE
		creates the datum coordinate system.
	 
   
  
	  To create a datum coordinate system at a different location or with a
		different orientation, do the following:
	 
	 
 
		- 
		  From the part or assembly in the current viewport, select a point
			 that will define the origin of the datum coordinate system or enter the
			 coordinates of the origin.
		  
		  
Abaqus/CAE
			 displays a temporary datum coordinate system at the selected point. The axes of
			 the datum coordinate system are aligned with the axes of the global coordinate
			 system.
		  
		 
 
		- 
		  From the prompt area, click Create Datum to
			 accept the default orientation of the temporary datum coordinate system or
			 select (or enter the coordinates of) a point that will lie on the
			 X- or R-axis.
		  
		  
Abaqus/CAE
			 recalculates the orientation of the temporary datum coordinate system. 
		  
		 
 
		- 
		  From the prompt area, click Create Datum to
			 accept the new orientation of the temporary datum coordinate system or select
			 (or enter the coordinates of) a point that will lie on the
			 X–Y or
			 R–
			 plane.
		  
		  
Abaqus/CAE
			 creates the datum coordinate system. You cannot move or rotate a datum
			 coordinate system.