Diagraph PA/4000, Руководство по обслуживанию, Страница: 154 / 213

Technician’s Guide 2-10
U7 through U11, and U23 are the IC’s that control the operation of all the memory modules.
U6 supplyís the voltage used to program the flash module. U7 & U8 buffers the addressing
of the modules. U9 buffers the data bytes. The other IC's primarily control what modules
are selected or what function is being done.
J4 - Cutter Signal Output
The remaining connector on the control board is J4. It has voltage and one control line
available that provides a signal for a media cutter. Q4 is the buffer devices that are
connected to Pin 2 of J4. If problems develop with the cutter signal, Q4 is most likely the
defective part.
To enable the cutter signal, SW1-8 on the back of the PA/4000 must be in the ON position.
A serial command may be sent to the PA/4000 to set the length of time the signal is active
during each print cycle. The cutter signal instruction as listed in the Prodigy Plus
Operator's Manual, is the "Hnnnn" command. It is a system level command and must be
sent preceded by the ASCII STX character, control "B". The "nnnn" after "H" is the amount
of time for the signal to be on in 24
µ
sec (microsecond) increments. The system default is
3125 for a 75 msec (millisecond). The cutter signal is a low going pulse on J4 pin 2.
PIN CONNECTIONS FOR J4
1 LOGIC GROUND
2 CUTTER SIGNAL OUTPUT
C CASE EARTH GROUND
EDGE SENSOR ASSEMBLY
The Edge Sensor Assembly is mounted to the center plate just below the print head. It includes
two small brackets to guide the paper between a pair of LEDs and optical receivers. These
inputs pass through the Applicator board J2 connector to 14PIN DIP Connector J8 to the Main
PCB J3 the Main PCB board samples and buffers these inputs to control the printing process.
PRINTHEAD
The printhead connects to the control board at J8. Most of the wires from the control board to
the printhead carry +24V and ground. The remaining pins control the serial transfer of data
from the control board to the printhead. When data is being sent from the control board to the
head, a clock pulse can be seen on pin 5 of U17. A latch pulse can be monitored on pin 11 of
U16 after so many clock pulses followed by strobe pulses on pin 8 of U15. Pin 11 & 12 supplies
5V to the head's logic circuits.
The head is a thin-film type head with latch and forward type logic to help decrease the delay
time needed between each printed dot row.
STEPPER MOTOR