Citizen Systems CLP-6001, CLP-6002 user manual 4 RS-232C protocol, Fig. Buffer in use

6.2.4RS-232C protocol

(1)X-ON/X-OFF system (see the figure)

This is a control system in which the data transmission request signal (X-ON (11H) code) and the data transmission stop request signal (X-OFF (13H) code) are output.

Requirements of output of X-ON code:

•When the power is switched to ON.

•When the remaining buffer is 2K bytes or less, the X-OFF is output, and the remaining buffer is 4K bytes or more.

Requirements of output of X-OFF code:

•When printer error occurs.

•When the remaining buffer is 2K bytes or less.

Receive buffer = 32K bytes

	4K bytes
	2K bytes
Receiving data
X-ON code output	X-OFF code output

Note: Even if each code is ready for output, the same code cannot be transmitted twice successively (except when the power is turned on or the printer is reset from the control panel).

Fig. Buffer in use

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