Repair manual

2-74
THEORY OF OPERATION
Table 2-14. Centronics Interface I/O Signal Lines (Con't)
Pin # Name Function
12 PE This signal line transmits hardware error data from the Digital
Palette to the host computer.
Under normal operating conditions, this signal line is not asserted.
If the Digital Palette experiences, a hardware malfunction (filter
jam, out of film, film previously exposed, etc.), both the PE and
ERROR signals lines are asserted.
The Digital Palette terminates the current data without executing
it, and waits for a Clear Error command from the host computer.
(The command buffer is emptied without executing the commands.
Parameter settings are not affected.)
13 SCLT This signal line is asserted when the Digital Palette is turned on
(powered up).
If this signal line is not asserted, no commands will be excepted by
the Digital Palette from the host computer.
35 ERROR This signal line transmits logical error data from the Digital Palette
to the host computer.
Under normal operating conditions, this signal line is not asserted.
If the Digital Palette experiences a logical error (unknown
command, command with an illegal parameter, operator error at
the keyboard, bugs in the software, etc), the ERROR signal line is
asserted.
The Digital Palette terminates only the current exposure. After a
logical error, the Digital Palette is ready to receive a new Start
Exposure. (Parameter settings are not affected. Any prior
exposure which was completely transmitted is not affected; it will
be properly exposed.)