User`s manual

7–69Digital Emulation

Set Top and Bottom Margins (DECSTBM)

ASCII Code ESC [ Pn1 ; Pn2 r

Hex Code 1B 5B Pn1 3B Pn2 72

Dec Code 27 91 Pn1 59 Pn2 114

Purpose Sets the top and bottom margins, and the page home line. These settings

are relative to the current origin point for page coordinates. (Refer to

“Page Format Select” on page 7–64.)

Discussion Pn1 sets the top margin and the page home line. Pn2 sets the bottom

margin. If the first parameter is greater than the second parameter, the

printer will ignore the sequence. The unit of measurement can be

character cells, decipoints, or pixels. Select the unit by using the Position

Unit Mode (PUM) and Select Size Unit (SSU) sequences. If you use

character cells, the height of each cell equals the current line height

setting. Change line height by changing the vertical spacing.

The top vertical margin defines the first printable line on a page. The bottom

vertical margin defines the last printable line. These are called hard margins

because you cannot print outside the area defined by the margins. The page

home line is the position of the first printable line on the page after a form

feed (FF).

Margins settings go into effect as soon as they are received. The printer will

set the margins where specified, except in the following cases:

• If Pn1 = 0 or is omitted, the top margin is unchanged.

• If Pn2 = 0 or is omitted, the bottom margin is unchanged.

• If Pn2 is greater than the form length, the bottom margin is set at the

bottom of the form.

• If the active position is less than the new top margin, the active position

is set to the new top margin. If the active line is greater than the new

bottom margin, the next printable character causes a form feed (FF).

• If the sequence sets the top margin below the bottom margin, the

command is ignored.

• The printer does not permit any part of the character box to be greater

than the bottom margin line or less than the top margin line.

If the form length is changed, the printer sets the top margin to line 1 and the

bottom margin to the form length.