Kodak Ektapro Slide Projector 4020 - Manual (Page 46)

b) Go to next slide position
Projector Status: There is a slide in the gate and it is projected.
Start action: The forward or reverse BUTTON is actuated
or next slide is selected with RANDOM
ACCESS.
See Slide Change Sequence, page 3-7.
RANDOM ACCESS: The MICROCONTROLLER selects shortest
distance to the next slide.
The MICROCONTROLLER energizes the TRAY MOTOR for 47 steps
(80 tray) or 27 (140 tray) for each slide.
The MICROCONTROLLER checks feedback from tray MOTION
CONTROL CIRCUIT.
If more than 4 feedback pulses are missed, exit to the failure routine.
For RANDOM ACCESS: The TRAY MOTOR ON until the position is
reached.
For FORWARD/REVERSE BUTTONS:
- tray moves only for one slide
- slide is projected
- if transport button is still pressed,
a slide is lifted up and the tray moves until button is released but
stops at the ZERO POSITION.
The MICROCONTROLLER sets the next position into memory.
The SLIDE LIFTER Down procedure starts.
For details, see Slide Change Sequence.
Yes
No
No
Set Tray Position
to next slide position
END
Tray Motor reverse Tray Motor forward
More than
4 Step Signals
missed
?
No
Yes
Transport Failure
Write failure
into Memory
Projector
inoperable
requested
Position
reached
?
Start
Slide LIFTER Up
Next Slide
Position
?
Slide LIFTER down
Slide projected
forwards
Power LED Blinking
reverse
figure 3-8
Service Manual SM 2547-1
03/98 3-10 Kodak AG, Stuttgart