TM 5-6675-318-14
(6) The front panel circuits provide a means of manually entering X- and Y-
p o s i t i o n d a t a , r e s e t , p e n c o n t r o l , a n d c h a r t h o l d d a t a t o t h e m i c r o p r o c e s s o r . The
front panel indicators make certain status information available to the operator.
S w i t c h e s mounted in the pen stalls provide information to the microprocessor as to
which stalls contain pens and if a pen is present in the plotter arm pen holder.
The X- and Y-initialize switches are also interfaced through the front panel PCA.
(7) The power supply converts the input ac line voltage into the necessary
dc voltages to operate the plotter. The power supply also contains the circuitry
for the reset pulse and for the electrostatic paper hold down circuits.
The detailed theory of operation is a block diagram description
3-12.2 Detailed.
which includes a functional description of each block of the diagram.
T h e interconnect PCA Al houses the
a. Interconnect PCA Al theory of operation.
24-pin connector for the input/output cable which connects the plotter with the
external controller on the HP-IB interface system.
b. The interconnect PCA Al also houses the CONFIDENCE TEST switch, LISTEN ONLY
s w i t c h , and the ADDRESS switch.
The CONFIDENCE TEST switch causes the plotter to
perform a check of the plotter electronics, plot seven vectors, and light the front
panel LEDs.
The LISTEN ONLY switch, when activated, disables the talk and serial
p o l l f l i p - f l o p s . T h e ADDRESS switch module contains five slide switches wired as
five single-pole double-throw switches.
Each switch will input either a low in the
0 position or a high in the I position to the address comparator circuits of the
main PCA A2.
c . M a i n PCA A2 HP-IB circuits. A 1 6 - l i n e b u s i s u s e d t o c a r r y d a t a a n d c o n t r o l
information between the interconnected devices and is divided into three sets of
lines:
3-120
