This section explains the different ways you can print with the R/3 System. In the R/3 System, a document is readied for printing using a special spool work process, which then passes the data to the spooler of the local computer. You can also access a print server using the network or you can print directly from the SAPgui.

When you print locally, the R/3 spool process sends the data to a printer that is set up on the operating system of the application server. The print request is then forwarded from the spool system of the operating system to the relevant printer. You can connect the printer locally to the computer or you can access it over the network.

Local printing is easy to implement and is also the fastest method to transmit data from the R/3 spool system to the printer. This is because there is no network connection between the R/3 spool process and the printer spooler, and the printer spooler takes over all communication tasks.

The R/3 spool process can access any printing system in the network that can handle the lpr/lpd protocol (line printer requester/ line printer daemon). This protocol originates from BSD UNIX and is an industry standard for controlling printing, and is supported by many modern operating systems and by network-enabled printers.

The line printer requester (lpr) is a client and sends the print data to the server (lpd side). Various data formats, for example, PostScript or PCL can be transmitted using this protocol.

Windows PCs do not usually have a line printer daemon (lpd). To be able to print using lpr/lpd, SAP developed its own lpd program for PCs called SAPlpd, which is installed with the SAP frontend. SAPlpd contains some extensions of the lpd protocol, for example, data compression, encryption using the SAP standard SNC (Secure Network Communication), and data transmission using the SAProuter.

Another option when printing from the R/3 System is frontend printing, which lets you access printers that are not defined in the R/3 spool system.

The technical aspects of frontend printing have changed often. The following describes the most up-to-date variant. We recommend that you use this variant as of Release 4.5. In this variant, the output data is transmitted directly over the SAPgui to the frontend PC. To do this, the existing connection between the SAPgui and the application server is used, so that an additional network connection is not required. The SAPgui starts SAPlpd on the frontend PC and transmits the print data to it. SAPlpd then sends the data to the Windows standard printer or to another printer installed on the operating system.

Unlike normal printing, the resolution of the document with frontend printing occurs in the dialog work process of the user. For this reason, frontend printing is only suitable for occasional interactive printing of small documents.

In a network with frontends, a printing infrastructure already exists in which you control the printers by using the network server or specially installed print servers. The existing network printers can also be used for printing from the SAP System.

The integration options depend on the system that the print server makes available. You can easily integrate the printing infrastructure into existing UNIX or Windows NT environments by using remote or frontend printing.

You can also integrate Novell environments by using an IP print gateway.