SATO M8490S, XL400/410, M8460S, M-8400RV, M8485S, M8459S, CL408/412 Receive Buffer, Multi Job Buffer

5. Interface Specifications Programming Manual

5.3 The Receive Buffer

The SATO RISC 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 con- trol 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 print- ing other jobs at the same time. It acts much like a “print buffer” to maxi- mize the performance of the host and the printer.The Multi Job Buffer mode is selected with DSW2-5. When using the RS232 Serial interface, the Multi Job Buffer uses either the Ready/Busy with DTR (pin 20) or X- On/X-Offflow control protocols. See these sections for more details. With an empty receiving buffer, the status of DTR is “high” (or an X-Onstatus 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-Offis sent) indicating the printer can no longer receive data. This condition is called “Buffer Near Full”.

0 62K 64K

DTR High or

X-On

DTR Low or

X-Off

Buffer Near Full

The receiving buffer will not be able to receive more data again until a “Buffer Available” condition occurs. This takes place when the receiving buffer has emptied so that only 56K bytes of data are being held (8K bytes

170 SATO RISC Printers