The Confidence Test; Interfacing The Plotter To Your Computer - HP 7470A Operator's Manual

The Confidence Test

The confidence test provides you with a visual indication that the
HP 7470A plotter is operating properly. This self·test checks the mechani­
cal and electronic functions of the plotter. It does
alternate pens, moving between scaling points PI and P2, drawing an
asterisk with pen 2, and moving 79 spaces along the X-axis. Pen 2 is
then stored and the pen holder returns to PI, indicating the confidence
test is completed. The confidence test cannot detect every possible
failure, but if the asterisk is drawn, there is a high probability that the
plotter is operating properly. If the asterisk is not drawn, the plotter is
malfunctioning and needs service. Refer to the Shipment paragraph for
instructions on how to obtain servicing assistance.
The confidence test is initiated by holding the
while turning on the plotter. The
after the pen holder starts to move.
NOTE:
The power-up initialization cycle is performed prior to the first
confi d ence test cycle
The confi d ence test will repeat approximately every 55 seconds and
be stopped only by turning off the plotter. Each confidence test cycle
automatically steps one space along the X-axis to draw the next
asterisk. This process continues until 80 asterisks are drawn in the first
row. The location of PI is moved up one row as each row of asterisks is
completed. PI is returned to its original default location when the page
is fill e d. The previously drawn asterisks are then redrawn. The delay
between each confidence test cycle can be reduced to approximately
0.25 second by pressing the left arrow push button. Holding the left
arrow push button down until a cycle is completed will return the delay
time to approximately 55 seconds.
NOTE:
Unless an intermittent problem is suspected, there is no need to
continue the confi d ence test cycles after the first asterisk is drawn

Interfacing the Plotter to Your Computer

Although interfacing the plotter to your computer is not difficult, there
are far too many plotter/computer combinations to cover in this manual.
The Interconnection Guide, HP Part Number 07470-90003, is furnished
with your plotter to provide this information. This guide contains
detailed instructions for interfacing your plotter with many commonly
used computers. If your particular computer is not included, experiment­
ing with the instructions given for a similar computer may solve the
problem. A short program that you can type into your computer is
included in each case to verify that communication is established
tween your plotter and computer.
18
PEN UP
.•
by selecting
80
push button down
PEN UP
pushbutton may be released
can
.•
be­