Addressing Data Underruns with HP FI-1000 and Navigator RIP

Introduction

Data underruns occur when an HP FI-1000 printer, particularly in high-speed print environments, runs out of data during a print job. This often results in print errors or degraded quality. One common solution to this issue is to increase the buffer size (also called the page pool size or poolsizemb in configuration files). This guide will walk you through adjusting this setting using the Navigator RIP software.


In the HP FI-1000 printer, two specific functions—screening and mandatory rotation—are handled inside the printer, and these can contribute to data underruns. Since these functions are mandatory and cannot be adjusted within Navigator RIP, this guide focuses on improving overall print data flow by adjusting the buffer size.

What are Data Underruns?

Data underruns happen when the printer does not receive data quickly enough to continue printing, causing gaps, stoppages, or errors in print jobs. These underruns typically occur in complex, high-speed environments where large amounts of data must be processed and sent to the printer rapidly.


Role of the Buffer (Page Pool)

The buffer, also referred to as the page pool, is a reserved section of memory that holds print data before it's sent to the printer. Increasing the buffer size allows the system to handle more data at once, reducing the risk of data underruns. In Navigator RIP, this setting is known as poolsizemb.


Changing the buffer, implications.

The printer doesn't start printing until the page pool is full.  So increasing the buffer means increasing the time it takes to start printing.  If you don't need a large buffer, don't use one.  If you are trying to figure out whether your data underruns are coming from the RIP or from somewhere else, then go ahead and change this number.  If you get no change in your underrun behavior, then the RIP was not your problem and the larger buffer isn't giving you a benefit.  Read on for instructions on changing the buffer.

Step-by-Step Guide to Adjusting the Buffer

1. Locate the Navigator RIP Configuration File

The setting to adjust the buffer size is typically found in an INI configuration file used by the Navigator RIP software. This file is named HPPW.ini.

  • Path to the File
    C:\Users\<YourUsername>\AppData\Roaming\Xitron\HPPW\
    Replace <YourUsername> with your specific Windows username.
  • You can also just open a Windows explorer window and type %appdata% and then hit <return>

2. Open the INI File

  1. Navigate to the folder where the HPPW.ini file is stored.
  2. Right-click on the HPPW.ini file and choose Open with > Notepad (or any other text editor).

3. Find the poolsizemb Setting

In the INI file, look for the following section and line:

[General] poolsizemb=4

The poolsizemb value refers to the size of the buffer in megabytes. In this example, it's set to 4 MB.

4. Increase the Buffer Size

  • Default Value: Typically, the buffer might be set to a low value like 4 MB.  Some versions are set up higher, at 32mb.
  • Recommended Adjustment: Increase this value incrementally. You can try 16 MB, 32 MB, 64MB or higher depending on your system's memory capacity and the complexity of the print jobs.

For example, change:

poolsizemb=4

To:

poolsizemb=32

Increasing it to 32 MB may provide enough buffer space to prevent data underruns.

5. Save the INI File

After adjusting the poolsizemb value:

  1. Save the file (press Ctrl + S or File > Save).
  2. Close the text editor.

6. Restart the Navigator RIP Software

To apply the changes, restart the Navigator RIP software. Once it is restarted, the new buffer size will take effect.

7. Test the Printer

  1. Send a complex or large print job to the printer that previously caused data underruns.
  2. Monitor the print output to see if the issue persists.

If the issue is resolved, then the new buffer size is sufficient. If underruns continue to occur, you can repeat the process and try increasing the buffer size further.

Important Consideration: Mandatory Screening and Rotation

In the HP FI-1000 printer, screening (the process of converting continuous-tone images to halftones) and mandatory rotation of data are handled inside the printer and cannot be adjusted within Navigator RIP. These mandatory functions can contribute to data underruns, but they cannot be avoided or managed through the RIP.

  • Screening: Converts images into a pattern of dots that the printer can output.
  • Mandatory Rotation: Ensures the job orientation is correct before printing.

Since these tasks are mandatory and handled by the printer, increasing the buffer size in Navigator RIP is your primary option to mitigate underruns.

Summary

In cases where data underruns occur with the HP FI-1000 printer, adjusting the buffer size (poolsizemb) in Navigator RIP can help improve print data flow and reduce the likelihood of underruns. Keep in mind that screening and mandatory rotation are handled internally by the printer and cannot be managed through Navigator RIP. However, increasing the buffer size can alleviate the pressure on the printer's internal processing capabilities and minimize data underruns.

If the issue persists, consider evaluating your system's overall network and data transmission performance to ensure optimal conditions for high-speed printing.