HP LaserJet 4100 HP PCL/PJL reference (PCL 5 Printer Language) - Technical Ref - Page 167

ER, Edge Rectangle Relative This command defines and outlines a rectangle using relative coordinates. Use ER when drawing charts or schematic diagrams that require rectangles. ER X,Y[;] Note Parameter X,Y increments Format current units Functional Range -230 to 230 - 1 Default no default The ER command defines and edges a rectangle using relative coordinates and the current pen, line type, and line attributes. The ER command includes an automatic pen down. When the command operation is complete, the original pen location and up/down status are restored. z X,Y Increments - Specify the opposite corner of the rectangle from the current pen location. The current pen location is the starting point of the rectangle. Increments are interpreted in current units: as user-units when scaling is on; as plotter units when scaling is off. The following illustration shows the current pen location in the lower left corner and the command's X,Y increment location in the upper right corner. When drawing a rectangle, these points can be in any two diagonally opposite corners. EN ER, Edge Rectangle Relative 21-23