Epson 420i (a), (b), (d), (d), (e), * ACK, * P.EMP, * ERROR, 1. Signal Levels, (a)POWER lamp blinks, (d)Buzzer is sounded, (b)ERROR signal goes LOW

(a)While performing initialization operations.(b)While the printer is inputting data with the STROBE signal.(c)During self test printing.

(d)When the printer is in the OFF-LINE state. (At this time, the ON-LINE lamp is not lit: 1) If the printer cover is open; 2) paper supply is depleted or P.EMPTY lamp is lit; 3) an error is detected or the POWER Lamp is blinking;

4)the ON-LINE switch is pressed.)

An ACK signal is output if the BUSY signal goes LOW only when BUSY is generated due to conditions l), 2) or 3).

* ACK

This signal that is synchronized with the falling edge of the BUSY signal is output after the initialization operations at power-on or after data is input.

* P.EMPThis signal goes HIGH when the printer is out of paper.* ERROR

This signal shows that the printer is in the error state and occurs in the following circumstances:

(a)If the circuit component’s temperature increases to an abnormal level.(b)If the right overrun switch is activated.

(c)If current flows through a pin of the printhead when printing is not required.

(d)If the home sensor is not operating properly, during initialization operations.

(e)If the RAM error is detected, while performing initialization operations.The sequence of events when an error occurs are as follows:(a)POWER lamp blinks(b)ERROR signal goes LOW(c)BUSY signal goes HIGH(d)Buzzer is sounded(e)Power for motion is turned off to terminate operations.To terminate the error condition:(a)Turn the power switch OFF and then ON again,(b)Input the INITIAL signal.(c)Press the RESET switch.

Electrical Conditions

1. Signal LevelsAll signals are TTL level.

HIGH level . . . . . . . . . . . . . . . . . . . . . . . . . . +2.4~5.0V LOW level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0~0.4V

Measured at the input pins on the printer.

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