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Main functions, Detection functions – Epson 420i User Manual

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MAIN FUNCTIONS

Detection Functions

1. Cover Switch

The printer cover open/close detection switch puts the printer in the OFF-LINE state.

It outputs a BUSY signal when the cover is opened. If the cover is opened during
printing, printing is terminated after the current line is finished, and the OFF-LINE

state is entered. When the cover is closed and the ON-LINE switch is pressed, the
ON-LINE state is entered and printing is resumed. For easier paper and ribbon in-
stallation, the printhead moves to the position which is approximately 10 cm away

from the home position when the printer cover is opened.

2. Right Overrun Switch
This switch detects the printhead carrier when it reaches the right most limit.

3. Temperature Detection Function
This detector recognizes abnormal temperature levels within the printer.

Note:

In the case of 2) or 3) if an abnormality is detected, the ERROR and BUSY

signals are output. The printer mechanism’s power supply is also turned

off.

To reset this condition, an INITIAL signal must be input, the RESET switch

pressed, or power must be turned off and then on again.

Errors

Buzzer and Power Lamp Blinking

Abnormal temper-

ature rise

Pin fires abnormally

Head carrier

overrun error

Home sensor

RAM error

Address (0000) H

(3FFF)H

RAM error

Address (4000)H

(7FFF)H

You can identify which section is malfunctioning by the buzzer sound or POWER

lamp blinking as shown above.

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