PN 9001024
Rev. B Jan. 2000
Page 3-2
SATO CL608 & CL612 SERVICE MANUAL
SECTION 3 – Interface Specifications
3-3 The Receive Buffer
The CL608/612 printer has the ability to receive a data stream from the host in one of
two ways. The receive buffer may be configured to accept one print job at a time or
multiple print jobs. The single job print buffer is generally used by software programs
that wish to maintain control of the job print queue so that it can move a high priority
job in front of ones of lesser importance. The multiple job buffer, on the other hand,
prints all jobs in the order they are received by the printer, and the order of printing
cannot be changed.
Single Job Buffer
The printer receives and prints one job at a time. Each job must not exceed 64 K
bytes.
Multi Job Buffer
The printer is able to continuously receive print jobs, compiling and printing other jobs
at the same time. It acts much like a print buffer to maximize the performance of
the host and the printer. When using the RS232 Serial interface, the Multi Job Buffer
uses either the Ready/Busy with DTR (pin 20) or X-On/X-Off flow control
protocols. See these sections for more details. With an empty receiving buffer, the
status of DTR is high (or an X-On status if using X-On/X-Off), meaning the printer
is ready to receive data. When the receive buffer is holding 62K bytes of data (2K
bytes from being full), DTR will go low (or an X-Off is sent) indicating the printer
can no longer receive data. This condition is called Buffer Near Full. See Figure 3-1.
DTR High or
X-On
Buffer Near Full
DTR Low or
X-Off
0
62K 64K
Fig. 3-1
To Next Page
Loading...
