Citizen CBM1000 manual Description of Input and Output Signals, Input signals to the printer

CAUTION:

•The first letter “n” of each signal name indicates that the signal is active “L”.

•If any one of the above signals is not available, bidirectional communication cannot be accomplished.

•In interfacing signals, be sure to use twist-paired wires for signal lines, and the return side must be connected to signal ground level.

•All interfacing conditions are specified based on C-MOS level and must satisfy the following characteristics. Also, specify the rising and falling time of each signal as 0.5 µs.

•Avoid transferring data by ignoring nAck or Busy signal; otherwise, the data may be erased.

•Make the interface cables as short as necessary.

6.2Description of Input and Output Signals

6.2.1 Input and Output Signals

Input signals to the printer

• DATA:	An 8-bit parallel signal. (Active “High”)
• nStrobe:	A strobe signal to help read 8-bit data. (Active “Low”)
• nInit:	A signal to reset the entire printer functions. (Active “Low”)
• nSelectIn:	This signal is made “High” when the printer is changed to IEEE

	1284 mode.
Output signals from the printer
• nAck:	An 8-bit data request signal, which is output at the end of a Busy
	signal. (Active “Low”)
• Busy:	A signal to indicate a busy state of the printer. Input new data
	when this signal is “Low”. (Active “High”)
• nFault:	This signal becomes “Low” when alarmed. At this time, all control
	circuits in the printer are deactivated. (Active “Low”)
• PEerror:	A signal to indicate that the paper supply has become low or has
	run out completely. (Active “High”)

•DK_STATUS: This signal becomes “High” when the switch is open, and “Low” when it is closed.

Power related signal

• +5 V:	A 5 V signal, which is pulled up by a 3.3 KΩ resistor.
• GND:	Common ground on circuits.

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