Tektronix PHASER 380, Service Manual

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Service Manual 5-5
Theory of Operation
5
I/O boards
The three I/O boards contain the most of the printers sensors and solenoids.
An internal data bus, called the I
2
C bus, connects all I/O boards to the main
board. Through this single bus, the main board can “poll” the I/O boards for the
state of the printer’s sensors as well as actuate the printer’s solenoids. This data
bus greatly simplifies the wiring that would otherwise be required for
monitoring many sensors and actuating solenoids.
The following table details what functions are related to each I/O board:
Network card
A rear panel slot contains one PhaserShare Network Card. One card provides an
RS-232C serial port and a LocalTalk port. A second, alternative card offers an
Ethernet port which includes standard support for EtherTalk, TCP/IP and
Novell NetWare. A third card provides a Token Ring interface supporting Novel
NetWare, TokenTalk, and TCP/IP.
Table 5-1. I/O board functions
I/O board 1 (left side of printer) I/O board 2 (lower-right side of
printer) I/O board 3 (upper-right side of
printer)
Head tilt solenoid Maintenance tray blade
position sensor Paper exit sensor
Head tilt home sensor Cap/wipe/purge home sensor Preheat exit sensor
X-axis home sensor Right maintenance tray
sensor Front cover switch
Media width home sensor Printhead lock sensor Exit cover switch
Drum temperature sensor Paper tray empty sensor Transfix cam solenoid
Media width sensor Handfeed/paper pick sensor Ink-load cover sensor
Paper pick electric clutch Tray type sensor Ink-low sensor
Upper feed roller electric
clutch Air valve solenoid Ink-out sensor
Lower feed roller electric
clutch Paper Preheater
temperature sensor
Maintenance tray cam
electric clutch Front panel
Transfix gear position sensor Transfix cam solenoid
Drum home position sensor
Drum encoder sensor
Left maintenance tray sensor