Printronix L5035 user manual Performance Considerations

Performance Considerations

Performance Considerations

The printer prints letter size and A4 size fanfold paper at 27 pages per minute portrait (one page every 2.2 seconds) and 35 pages per minute landscape. To sustain printing at full speed, data for each page must be received and rendered in less than 2.2 seconds for portrait mode (otherwise the printer will pause).

Failure to print at full speed may be caused by one or more of the following:

•an inefficient application program

•an insufficient communication interface bandwidth

•a slow host computer

•a low priority on the host printer port or printing task

•a highly complex print job, usually containing a large number of characters and graphics that exceeds the bandwidth of the controller

An inefficient application program is listed first because a highly efficient program sends fewer characters to the printer than a less effective program, and it can be used to overcome the other four causes of performance problems. This is especially true of IGP/ VGL and IGP/PGL applications, due to the power of these printer emulations. In many cases, converting a program from IGP/VGL to IGP/PGL results in substantial performance improvements.

Wide width printing jobs with a large number of characters on a page can exceed the communication bandwidth and/or the communication speed of the host computer. A plain text print job of 132 columns by 66 lines requires a sustained data transmission rate of 3485 characters per second, or for serial communication a sustained throughput of 34.85 KBaud (assuming 8 bits of data, 1 stop bit, 1 start bit, and no parity bit). In this case, RS-232 would not be an acceptable selection for communication because the maximum RS-232 baud rate of 19.2 KBaud is less than the required 34.85 KBaud sustained throughput. Sustaining high communication data transfer rates may require the host computer to be tuned to meet the printer’s speed requirements.

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