TM 5-6675-323-14
Environmental Range
3 2 F (0C) to 131F
Temperature
(55C)
5 % to 95% relative
Humidity
3-12.
TECHNICAL PRINCIPLES OF OPERATION.
3-12.1
General.
a. The plotter has an internal microprocessor which interprets and responds to
c o m m a n d s in the form of program statements from the HP-9825A Desk-Top Computer. It
directs the plotter's internal circuits to perform the desired operation.
b . T h e p l o t t e r d r a w s l i n e s u s i n g v e c t o r d a t a r e c e i v e d f r o m t h e c o m p u t e r in the
f o r m o f a d i g i t a l w o r d . T h e p l o t t e r t h e n t r a n s l a t e s t h e v e c t o r d a t a i n t o a n analog
signal which drives the chart pen.
c . T h e p l o t t e r c a n c o n s t r u c t a p l o t b y t r a c i n g a l i n e f r o m p o i n t t o p o i n t in a
series of data points, each point received as a digital word. If the sequence of
d a t a points is not continuous, an insertable ROM can calculate and provide the
missing points.
d. The plotter can also send coordinate data back to the computer. Sending of
plot data by plotter is called point digitizing.
In digitizing, the digitizing
sight is loaded like a regular pen and is manually positioned on a point using the
local control push-button switches on the plotter's front panel. Pressing the ENTER
key, with the sight in the pen down position, will send the coordinates of the pen's
position to the computer.
e. The plotter is controlled and operated by programming statements sent from
the computer.
It can only be operated independently when performing self-tests, the
confidence test and manually editing charts. The confidence test and self-tests are
preprogrammed and, once initiated, are controlled internally by the microprocessor.
Manual chart editing is accomplished using the front panel pen control buttons.
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