SATO DR300 manual XON / Xoff

Models: DR300

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DR300 Operator Manual

Chapter 10 - Serial Interface

 

 

XON / XOFF

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 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” is reached and an X-Onwhen the data level of the buffer drops below the “Buffer Available” mark. When the printer is taken offline manually, it transmits an X-Offindicating it cannot accept data. When it is placed back online 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 online, it transmits an X-Onindicating it is again ready to accept data.

Data stream (ESC + “A” ~ ESC + “Z”) from host might not be fully received by printer under the following conditions:

Printer is in printing process during Single Job Buffer Mode

Printer is engaged with error condition

1 : Cable connection

 

Host

Printer

FG

 

1 FG

 

RD

2 SD

SD

3 RD

SG

 

7 SG

 

Some host needs looping of RS and CS at host side to keep signal High.

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Page 80
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SATO DR300 manual XON / Xoff