(12) Input/Output Signals:
Compatible mode
cData 1 ~ 8 (Printer ← Host)
z Input data signals for the 1st to 8th bits z Logic 1 is the “High” level.
z Min. data pulse width of 2.5 µsec
dnStrobe (Printer ← Host)
z Synchronizing signal for reading the above data
z Normally at the “High” level. The data is read at the rise of the Low level pulse. z Minimum data pulse width of 0.5 µsec
eBusy (Printer → Host)
z This signal indicates that the printer is in a Busy state.
z When initialized after the power is turned on, the printer becomes ready to receive data and turns the signal to the “Low” level.
z The signal turns to the “High” level (in a Busy state) when data is set from the host (at the fall of the nStrobe signal).
z The signal turns to the “Low” level when the printer reads the data.
z When the blank positions in the receive buffer are 712 bytes or less, the printer keeps the signal at the “High” level (in a Busy state) for 10 seconds when data is set from the host, to extend the data read interval.
z When there are no blank positions in the receive buffer, the printer stops reading data. Then, it keeps the signal at the “High” level (in a Busy state) until there are blank positions in the receive buffer when data is set from the host.
z The signal is kept at the “High” level (in a Busy state) until the current state (one of the following states) is reset.
•Pause state caused by the [PAUSE] key
•Paper end state
•Ribbon end state
•Head open state
•Printer error state
•Initialization in progress upon receipt of the nInit signal
fnAck (Printer → Host)
z This signal indicates that the printer has read the data set by the host and is ready to receive the next data.
z One of 2 types of timing for Ack can be selected.
z One is normally at “High”. The Ack signal should be sent to match the fall of the Busy signal and the end of the Low level of the Ack signal for about 0.7 µsec. The host should usually set data after the Ack signal is turned from “Low” to “High”, or after the fall of the Busy signal. (Default timing)
z The other is normally at “High”. It is at “Low” for about 5 µsec. after the fall of the Busy signal. The host should usually set data after the Ack signal is turned from “Low” to “High”.
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