Citizen Systems CBM-910 Type II Description of Input/Output Signal, DTR Data Terminal Ready

6.3Description of Input/Output Signal

(1)Input signal

1)TD (TRANSMIT DATA)

Serial transmission data signal.

2)RD (RECEIVE DATA) Serial receive data signal.

3)DTR (DATA TERMINAL READY)

Input command or data while this signal is in ready state (space). Data input while the signal is BUSY (mark) will cause an overrun error to occur. Data can be provided to the input buffer even if the printer is printing. Busy state may also occur when power is applied, or during test printing, on-line, or when the printer is reset.

4)RESET (L) (TTL level)

Signal for resetting the whole printer. Reset is activated with L level of 4 ms or more.

5)RESET (RS-232C level)

Signal for resetting the whole printer. Reset is activated with Space of 4 ms or more.

6)FG (FRAME GND) Case ground.

7)GND

Signal ground for the circuit.

(2)Data configuration

Mark

Space

t

b0, b1, b2 • • • • •

(1) (2) (3)

(1)Start bit (1 bit)

(2)Data bit (8 bits)

(3)Stop bit (more than 1 bit)

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