Paper End Detection Function; Cover Open Detection Function - Epson DFX-8000 Service Manual

RAM check abnormality:
driver abnormality:
The following states are also regarded as errors, and the interface signals
are similarly set.
When a paper end is detected.
When an open cover is detected.
When the printer is set off-line using the ON LINE switch.
1.3.8

Paper End Detection Function

Paper end is detected using the paper end sensor on the printer mechanism. When a paper end is
detected, the printer indicates it using the lamp and buzzer on the control panel. At this time the interface
signals should be set as follows to set the printer to the off-line mode.
This disables data reception.
Parallel interface
BUSY signal: High
PE signal: High
ERROR signal: Low
Serial interface
DTR (REV) signal: MARK
X code (DC code): XOFF (DC3/13H)
When a paper end is detected, new paper should be loaded, or another form should be selected by
switching the tractor. The printer should then be set to the on-line mode.
1.3.9

Cover Open Detection Function

The printer always monitors the open\close state of the top cover. When the open cover sensor detects
an open cover, the following actions occur:
The printer is set to the off-line mode.
The buzzer sound.
Carriage speed is decelerated rapidly.
Opening the cover during printing is extremely dangerous because the carriage
moves very rapidly during printing (when the cover is closed). The above
actions guarantee the safety of the operator when the cover is opened. To
recover from this state, the following sequence should be followed.
[STEP 1] Close the top cover.
During initialization, a READ/WRITE check is performed for
all RAM in the control circuit to check for errors.
- CPU RAM
— Lower address RAM
- Upper address RAM
A short circuit in a printhead
1-30
drive transistor was detected.