The Receive Buffer - SATO M-84PRO Operator's Manual

Section 6. Troubleshooting
WARNING: Never connect or disconnect interface cables (or use a switch box) with power
applied to either the host or the printer. This may cause damage to the interface
circuitry in the printer/host and is not covered by warranty.

THE RECEIVE BUFFER

The M-84PRO printers have 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 2.95 MB.
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 RS232C 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 2.0 MB of data (1 MB 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."
Page 6-2 PN 9001105 Rev. A SATO M-84PRO