The Velocity Select Instruction, Vs - HP 7470A Interfacing And Programming Manual

SYNTAX SP pen number (terminator)
or
SP (terminator)
EXPLANATIONThe pen parameter must be in the range of -32 768 to
32 767. Decimal fractions are truncated. An odd-numbered parameter
selects the pen from the left stall; an even—numbered parameter selects
the pen from the right stall. A zero parameter or no parameter stores
the pen. When a pen parameter is less than -32 768 or greater than
32 767,an error is generated and the pen does not change.
The Velocity Select Instruction, VS
DESCRIPTION The velocity select instruction, VS, specifies the pen­
down speed for plotting and labeling operations.
The instruction is used to set Velocityto a speed other than the
default velocity of 38.1 cm/s and to change the acceleration from its
default value of 2 g (980 cm/s2). This instruction should be used to slow
velocity to 10 cm/s when plotting on transparency film. A slightly
thicker line can be created by slowing down the pen speed on any
medium. A pen nearing the end of its life will write with a clearer,
sharper, more solid line if the velocity is slowed.
SYNTAX VS pen velocity (terminator)
or
VS (terminator)
A VS command without parameters sets pen velocity
to its default velocity of 38.1 cm/s (15 in./s) and acceleration to 2 g (980
cm/s2). A VS command with parameters sets the pen velocity for hori­
zontal or vertical pen-down moves to the value specified by the first
parameter and slows the acceleration to 0.5 g. Anything after the first
parameter is ignored. Parameters must be in the range 0 to 127.9999.A
velocity of 0 is set to 0.38 cm/ s. Velocity can be set in increments of 0.38
cm/s. Parameters are rounded to the nearest multiple of 0.38 cm/s.
Negative parameters and parameters greater than or equal to 97 set an
error condition (error 3) and the velocity does not change. Parameters
between 38.1 and 96 set velocity to its default value of 38.1 cm/s.
When either the horizontal or vertical velocity falls in the range 0.38 to
3.8 cm/s, it is reset to a slower or faster velocity to avoid this range.
This is done to assure lines of high quality. The change is most notice­
able when a line is almost vertical or almost horizontal. Pen—down
moves will be at the specified velocity except when such adjustment is
necessary.
Execution of a VS command with a parameter of 38.1 will slow the
acceleration, giving the highest line quality at that maximum speed.
CONTROLLING THE PEN AND PLOTTING 3-3