SATO M-8400RV manual RS232C Interface Signals, PIN Direction Signal Definition

Section 5. Interface Specifications

PIN ASSIGNMENTS

		RS232C Interface Signals
PIN	DIRECTION	SIGNAL DEFINITION
1	Reference	FG (Frame Ground)
2	To Host	TD (Transmit Data) - Data from the printer to the host computer.
		Sends X-On/X-Off characters or status data (Bi-Directional
		protocol).
3	To Printer	RD (Receive Data) - Data to the printer from the host computer.
4	To Host	RTS (Request to Send) - Used with Ready/Busy flow control to
		indicate an error condition. RTS is high and remains high unless
		the print head is open (in this case, RTS would return to the high
		state after the print head is closed and the printer is placed back
		on-line) or an error condition occurs during printing (e.g., ribbon
		out, label out).
5	To Printer	CTS (Clear to Send) - When this line is high, the printer assumes
		that data is ready to be transmitted. The printer will not receive
		data when this line is low. If this line is not being used, it should be
		tied high (to pin 4).
6	To Printer	DSR (Data Set Ready) - When this line is high, the printer will be
		ready to receive data. This line must be high before data is
		transmitted. If this line is not being used, it should be tied high (to
		pin 20).
7	Reference	SG (Signal Ground)
20	To Host	DTR (Data Terminal Ready) - This signal applies to Ready/Busy
		flow control. The printer is ready to receive data when this pin is
		high. It goes low when the printer is off-line, either manually or due
		to an error condition, and while printing in the Single Job Buffer
		mode. It will also go low when the data in the buffer reaches the
		Buffer Near Full level.

READY/BUSY FLOW CONTROL

Ready/Busy is the hardware flow control for the serial interface on the M-8400RV printer. By raising/lowering the voltage level on Pin 20 of the RS232 port, the printer notifies the host when it is ready to receive data. Pin 4 (RTS) and pin 20 (DTR) are the important signals on the printer for this method of flow control. The host must be capable of supporting this flow control method for it to function properly.

SATO M-8400RV 9001041 Rev. D Page 5-4