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Cable Requirements
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-Off flow 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-Off operates 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-On is sent out. In the Single Job Buffer mode,
when the printer receives a viable job, it transmits an X-Off and begins printing.
When it is done printing, it transmits an X-On. In the Multi Job Buffer mode, the
printer sends an X-Off when the “Buffer Near Full” level is reached and a X-On
when the data level of the buffer drops below the “Buffer Available” mark. When the
printer is taken off-line manually, it transmits an X-Off indicating 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-On is 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-Off as soon as an error condition is detected. When the error is cleared and the
printer is placed back on-line, it transmits an X-On indicating 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.
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.
Section 5. Interface Specifications
SATOCLSeriesPrinters9001035Rev.EPage5-5