Printronix L5535, Maintenance Manual

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II–222
Appendix A
Unit Interface
Data 4
⇒
Load
⇒
Strobe 1 (*STB1)
⇒
Strobe 2 (*STB2)
⇒
Logic power (VCC)
⇒
Logic power supply – (VSS)
⇒
LED drive power (VDD)
⇒
LED drive power supply – (GND)
⇒
Clock
The Clock signal clocks the data into the LED array.
Data 1 through Data 4
The signals Data 1 through Data 4 are serial signals. They carry the data that
controls the lighting of the various LED chips. Each signal is asserted to light
the LEDs, and de-asserted to extinguish the LEDs.
The print head of this machine is composed of 4 LED array blocks, as
diagrammed below. The Data 1 through Data 4 signals transmit the
illumination data to the LED chips (individual light-emitting diodes) that make
up the LED array.
Following are the quantity of LED chips that make up each of these four LED
array blocks (i.e., the number of dots which can convey illumination data in
response to the Data 1 through Data 4 signals):
For 400 DPI (total number of emitters 5888):
Signal Number of dots
Data 1 1536 dots
Data 2 1536 dots
Data 3 1536 dots
Data 4 1280 dots
Data Shift Direction
LED Array
Block LED Array
Block LED Array
Block LED Array
Block
IC1 IC13 IC25 IC37
Data 1 Data 2 Data 3 Data 4