SATO CL608VA, CL612VA manual Cable Requirements, Data Streams, On/X-Off Flow Control

				Section 5. Interface Specifications
Cable Requirements
HOST	INTERCONNECTION			PRINTER
FG	←⎯⎯⎯⎯⎯⎯⎯⎯⎯→		1	FG (Frame Ground)
TD	⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯→		3	RD (Receive Data)
		⎯⎯⎯⎯⎯	4	RTS (Request to Send)
		⎯⎯⎯⎯⎯	5	CTS (Clear to Send)
		⎯⎯⎯⎯⎯	6	DSR (Data Set Ready)
*	←⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯		20	DTR (Data Terminal Ready)
SG	←⎯⎯⎯⎯⎯⎯⎯⎯⎯→		7	SG (Signal Ground)

*This connection at the host side of the interface would depend upon the pin that is being used as the Ready/Busy signal by the driving software. Typically, on a PC, it would be either CTS (pin 5) or DSR (pin 6) on a DB-25 connector.

Data Streams

Once the flow control method has been chosen for the RS232C interface, the data stream must be sent in a specific manner. The STX and ETX control characters must frame the data stream.

<STX><ESC>A . . Job#1 . . <ESC>Z<ETX><STX><ESC>A . . Job#n . . <ESC>Z<ETX>

NOTE: All characters, including STX, ESC and ETX are in ASCII.

X-On/X-Off FLOW CONTROL

X-On/X-Offflow control must be used whenever hardware (Ready/Busy) flow control is not available or desirable. Instead of a voltage going high/low at pin 20, control characters representing “Printer Ready” (X-On=11 hexadecimal) or “Printer Busy” (X-Off= 13 hexadecimal) are transmitted by the printer on pin 2 (Transmit Data) to the host. In order for this method of flow control to function correctly, the host must be capable of supporting it. X-On/X-Offoperates in a manner similar to the function of pin 20 (DTR) as previously explained. When the printer is first powered on and goes on-line, an X-Onis sent out. In the Single Job Buffer mode, when the printer receives a viable job, it transmits an X-Offand begins printing. When it is done printing, it transmits an X-On. In the Multi Job Buffer mode, the printer sends an X-Offwhen the “Buffer Near Full” level is reached and a X-Onwhen the data level of the buffer drops below the “Buffer Available” mark. When the printer is taken off-line manually, it transmits an X-Offindicating it cannot accept data. When it is placed back on line manually, it sends an X-On, indicating it is again available for receipt of data. If an error occurs during printing (paper out, ribbon out), the printer sends nothing in the Single Job Buffer mode since the last character transmitted was an X-Off. When the error is cleared and the printer resumes printing, no X-Onis sent until the current job is completed and the printer is once again ready to receive the next job. If it is in the Multi Job Buffer mode, it sends an X-Offas soon as an error condition is detected. When the error is cleared and the printer is placed back on-line, it transmits an X-Onindicating it is again ready to accept data.

Upon power up if no error conditions are present, the printer will continually send X- On characters at five millisecond intervals until it receives a transmission from the host.

SATO CL Series Printers 9001035 Rev. E Page 5-5