Converting SCS and 3270 data streams to PCL data streams

In each printer definition, you can select a NetSpool formatting option. The formatting option controls how NetSpool formats the data streams created by your VTAM® applications. You can select one of these formatting options:

• Convert to line (default)
• Convert to PCL
• None

This section describes the Convert to PCL formatting option. When you select the Convert to PCL option, NetSpool converts SCS data streams (on VTAM LU type 1 sessions) and 3270 data streams (on VTAM LU type 0 or type 3 sessions) to Printer Control Language (PCL) 5 data streams.

You can select Convert to PCL for printers controlled by IP PrintWay™ that accept PCL data streams. When you select this option, IP PrintWay automatically transmits PCL data streams created by NetSpool to the printer without additional page formatting.

Most printers that accept PCL data streams can also accept text data streams. Therefore, for these printers you can select either the NetSpool Convert to PCL or the Convert to line formatting option. The Convert to PCL option provides these additional functions:

• For SCS data streams, NetSpool can support this additional print control functions in the input data stream, thereby providing better print fidelity:
  • Line-density and print-density
  • Page orientation
  • Paper-source and output-bin
  • Job-separation
  • Duplex
  When you select the Convert to line option, NetSpool cannot fulfill these requests in the input data stream due to limitations in line data.
• For SCS data streams, NetSpool can automatically change the orientation of the page between portrait and landscape on a page by page basis. NetSpool can also reduce print output, if necessary, to make the data fit on the line or page.
• For both SCS and 3270 data streams, NetSpool lets you specify the line density, print density, and page orientation for each printer in the printer definition. This means that you do not need to set these values at the printer's control panel or specify the PCL commands in the IP PrintWay Document header field.

The Convert to PCL option is not suitable, however, in these printing situations. Therefore, in these situations, instead select the Convert to line option:

• The printer is controlled by JES or PSF. JES and PSF do not accept PCL data.
• Your VTAM applications generate DBCS data. NetSpool cannot support DBCS data when you select the Convert to PCL option.
• You want to use a form definition and page definition to format your data and print it on a PCL printer. In this case, select the NetSpool Convert to line option and also use the AFP to PCL transform to convert line data streams created by NetSpool to PCL data streams.

When you select the Convert to PCL option, NetSpool converts EBCDIC data, SCS controls, and 3270 controls in the input data stream to ASCII data and PCL commands. NetSpool supports most of the SCS and 3270 controls in the input data stream that are associated with printing. NetSpool ignores those SCS and 3270 controls for which no equivalent PCL commands exist. NetSpool writes PCL data streams to the JES spool in variable-length, blocked format, with a maximum record size of 32752 bytes.

To fill in the fields in the printer definition that are related to NetSpool formatting, you should understand these functions that NetSpool provides when you select the Convert to PCL option:

• EBCDIC to ASCII conversion: NetSpool converts data from EBCDIC to ASCII before writing it to the JES spool. To convert data to ASCII, NetSpool converts data from an EBCDIC code page (also called the document code page) to an ASCII code page (also called the printer code page) using the IBM® iconv utility. For most printing situations, the default document and printer code pages that NetSpool uses are suitable. However, in each printer definition, you can specify different document and printer code pages.
• Page formatting: NetSpool formats data into lines and pages before writing it to the JES spool. The page formatting is different for SCS and 3270 input data streams.

  SCS data streams: NetSpool uses SCS Set Horizontal Format (SHF) and SCS Set Vertical Format (SVF) controls to format data into lines and pages. The SHF and SVF controls specify page-formatting values such as line length, page length, margins, and tabs. The SHF and SVF controls take effect immediately and remain in effect until either the next SHF or SVF control or until NetSpool starts writing a new output data set to the JES spool.

  If the SCS data stream does not contain SHF and SVF controls, NetSpool uses default values. In each printer definition, you can specify the default values that NetSpool is to use for the line length, page length, margins, and tabs.

  3270 data streams: NetSpool uses page-formatting values in the 3270 Write Control Characters (WCCs) in the 3270 data stream to format data into lines and pages. To change page-formatting values for 3270 data, the application programmer must change the WCCs generated by the VTAM application that creates the 3270 data. For 3270 data streams, NetSpool does not use any of the default page-formatting values for line length, page length, margins, and tabs that you specify in the printer definition.

• Print density, line density, and page orientation: NetSpool can generate PCL commands to set the print density (characters per inch), line density (lines per inch), and page orientation (portrait or landscape). NetSpool processing differs for SCS and 3270 data streams.
  • SCS data streams: NetSpool converts the SCS Set Print Density (SPD) and SCS Set Line Density (SLD) controls in the input data stream to corresponding PCL commands. In each printer definition, you can specify the default print density and line density that NetSpool is to use when the SCS data stream does not contain SPD and SLD controls. The SCS data stream does not contain orientation controls. However, in each printer definition, you can specify the page orientation that NetSpool is to use. Also, you can request that NetSpool automatically determine the appropriate orientation of each page, as described below.
  • 3270 data streams: 3270 data streams do not contain print density, line density, and page orientation information. In each printer definition, you can specify the print density, line density, and page orientation that NetSpool is to use.

  For both SCS and 3270 data streams, if you do not specify density or orientation values in the printer definition, the values set at the printer's control panel are used unless the density and orientation are specified in another location. Density and orientation can be specified in several places. If they are specified in more than one place, the first value in this list is used. For example, a value specified in the SCS data stream overrides all other values.

  1. SCS controls that occur in the input SCS data stream, including any PCL commands and SCS controls added by the NetSpool Transparent Data exit
  2. PCL commands or SCS controls added by the NetSpool Beginning of File exit
  3. Density and orientation values you specify in the printer definition under the NetSpool PCL Conversion heading
  4. PCL commands you specify in the IP PrintWay Document header field in the printer definition
  5. PCL commands added by the IP PrintWay Begin Data Set exit
  6. The default value set at the printer's control panel
• Automatic page orientation (SCS data streams only):

  When you select the automatic page orientation option in the printer definition, NetSpool automatically determines the appropriate orientation (portrait or landscape) of each page based on the line length and page length of that page. If necessary, NetSpool reduces the size of the print (the font size) and increases the line density so that data fit on a line.

  NetSpool uses the line and page lengths specified in SCS controls and in the Print density, Line density, Line length, and Page length fields to determine the appropriate page orientation for each page. If the line length is greater than the page length, NetSpool sets the orientation to landscape. Otherwise, it sets the orientation to portrait. When NetSpool sets the orientation to landscape, if the Line length field (or the MPP in the SCS SHF control) is greater than 106, NetSpool sets the print density to 15 characters per inch and the line density to 8 lines per inch.

For more information, see:

• z/OS Infoprint Server User’s Guide for tables that describe how NetSpool converts SCS and 3270 data streams to PCL data streams
• z/OS Infoprint Server Customization for information about NetSpool exits