Citizen CMP-10 manual Explanation of Input/Output Signals, 14, 15 pin Communicate mode setting

5.3Explanation of Input/Output Signals

(1)RXD

This is signal, receiving data from the host. On occurrence of framing error, overrun error, or parity error, the data is printed as “?”.

(2)TXD

This signal is for data flow control by X-ON/X-OFF. If data remains in the printer’s input buffer is 2048 bytes or less, the printer transfers a DC3 (13H: Data Receive Not Ready) signal to the host. If data in the input buffer exceeds 4096 bytes, the printer transfers a DC1 (11H: Data Receive Ready) signal to the host.

(3)Vcc

This is a power supply (+5 V). The signal is not use in the standard serial cable!

(4)GND

This is a GND on the circuit.

(5)Auto turn-on

The printer can be turned on by using RTS signal from the host

CAUTION: Ensure that the RTS signal is deactivated when your application software not using the printer as auto turn-off function is disabled when RTS is active

14, 15 pin (Communicate mode setting)

Using dedicated cable makes these pin short-circuited.

If these pins are short-circuited, printer sets the communicate mode to serial communication. If these pins are not short-circuited, printer set the communication mode to infrared.

5.4 Error Detection

Framing and overrun are detected. On detection of any error, the data are stored in the buffer as “?”.

(1)Framing Error

With “space” state having been detected on detection of a stop bit, error takes place. The data are stored in the buffer as “?”.

(2)Overrun Error

On detection of an overrun error, the data are stored in the buffer as “?”.

5.5Buffering

This printer incorporates 64K byte buffer. This allows most print jobs to by fully buffered so that the host can continue quickly.

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