HP 7470A Interfacing And Programming Manual page 92

Use of DI and SI
When DI and SI commands are used together,'the DI command estab­
lishes the label's direction and the SI command establishes its size. The
direction serves as the axis along and about which labels (written with
negative SI parameters) are mirrored. Positions of P1 and P2 do not
affect the labels. Refer to The Absolute Direction Instruction, DI, and
The Absolute Size Instruction, SI.
Two examples of mirrored labels are shown below. In the first example,
the DI parameters 3,2 place the directional line in the first quadrant.
The negative width parameter of the SI command mirrors the label in
the right-to-left direction. In the second example, the DI parameters
3,-2 place the directional line in the fourth quadrant. The negative
height parameter of the SI instruction mirrors the label top-to-bottom.
Use of DR and SI
5-22
When DR and SI commands are used together, the label size is deter­
mined by the SI command and does not change with changes in the
settings of P1 and P2. However, changes in the settings of P1 and P2
will affect the label direction. The algebraic differences (P2x' Plx) and
(P2y —Ply) are multiplied by the run and rise parameters of the DR
command. The resulting parameters, when applied to the standard
coordinate system, determine the label baseline. Mirroring about this
baseline is determined by the signs of the SI parameters.
In illustration 3, P1 and P2 are at their default settings so the algebraic
differences (P2,; —Plx) and (P2y —Ply) are both positive. The DR
parameters 3 ,-2 are used as is and establish the directional line in the
fourth quadrant. The negative SI height parameter mirrors the label
from top to bottom.
LABELING