X-On/X-Off Flow Control - SATO M-5900RV Operator And Technical Reference Manual

Section 5. Interface Specifications
Cable Requirements
H O S
F G
T D
*
S G
* 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-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
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 .ull" 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), 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 detected. When the
error is cleared and the printer is placed back on-line, it transmits as X-On
indicating it is again ready to accept data.
Page 5-6
T N I T E R C O N N E C
SATO M-5900RV Operator and Technical Reference Manual
T O I N P R
1 F G F ( a r m
3 R D R ( e c i e
4 R T S R ( e q
5 C T S C ( e l r a
6 D S R D ( a a t
2 0 D T R D ( a a t
7 S G S ( g i n l a
N I T E R
e G o r u n ) d
e v D t a ) a
u e t s o t S e n ) d
o t S e n ) d
S t e R e a d ) y
T r e m n i l a R e a d ) y
G o r u n ) d
PN 9001081
Rev. C