Introduction to the SAP Access Methods SAP BASIS

Access methods are very necessary not only for defining the type of printing (local, remote, PC printing), but for defining the printing performance parameter, because the way the data is transferred from the SAP spool to the host spool affects the final throughput. Not all access methods are supported by all the operating systems and types of connections. A brief description of the available access methods follows:

  • CDirect operating system call. This access method is commonly used for local printing when defining output devices that are managed by Windows NT systems. The spool work process and the print manager that drives the printer are running on the same server. This is applicable even to printers that are shared in the LAN. Behaves similarly to access method L in UNIX systems. Access method C does not allow for requesting status information from the SAP spool system to the Windows NT print manager.
  • IArchive service. This access method is for defining an output device to be used as an archiving system. You can define a printer as an archive service. When doing this, and users send documents to the spool system, these documents can be transferred directly both to the archive system as well as to the actual printer.
  • LPrint locally via LP/LPR with signal. The SAP spool work process will use a command to transfer the spool requests to the host spooler. The actual commands, such as lp or lpr, are operating system dependent, and are set in the SAP instance profile parameter rspo/host_spool/print. Both the spool work process and the host spool are running on the same server.
  • PDevice pool. This special access method is used for defining device pools. With device pools, output requests can be sent to more than one printer at a time, and they can be used for defining several printers to perform automatic print load balancing. Devices that compose a device pool must be local, which means that they must be accessible from the host spooler or print manager where the spool server resides.
  • UPrint on LPDHOST via Berkeley protocol. This access method is used for implementing remote printing or even PC printing when the SAP spool work process is running on a different host than the server where the printer is connected. With access method U, the spool work process will transfer the formatted data to the target host spooler through the network link. Since there is the possibility of printing large volume jobs, this method is not recommended for slow WAN connections, because it might slow down the processing of other print requests. This method can be used for UNIX and Windows printers; however, it is not supported in some of the operating systems.
  • SPrint on LPDHOST via SAP protocol. This access method is used both for remote printing and PC printing. It uses a special SAP communication protocol that includes data compression, transmission of the SAP title, and so forth. Access method S might be slower than method U and is mainly used for printers that are defined using the SAPWIN device type.
  • XSAP comm. This method is used for devices which are managed by the SAP spool system and handled by the SAP communication server, such as FAX, Telex, and EDI.
  • FPrint on front end (locally) via SAPLPD. This is a variant for local or frontend printing. This access method is designed for those end users who require printing on their local (or default) assigned or attached printer, which has not been defined on the SAP system as an output device. In these cases the SAP dialog work process handling the user process sends the formatted request to the SAPLPD or lpd process, according to the type of workstation. If the SAPLPD process was not previously started, the system will start it automatically. More information about local PC printing can be found in a later section.
  • ZCommand interface spool exit. This method exists for compatibility reasons but is being replaced by access method E from release 4.0 onward.
  • ECommand interface/RFC interface to OMS. This access method is designed for output requests that will be sent to an output management system (OMS) that is compatible with R/3 printing commands.

Troubleshooting Printing Problems

The following is a list of possible steps to perform when you notice printing problems in the system. These problems can be very different: no printing at all, slow printing, printing garbage, and so forth. In any case, you should

  • Check and monitor the spool work process from the Process Overview transaction as well as from the operating system spool (print daemon or print manager). Also, check that the message server is working properly.
  • Particularly, check that you can print normally from your operating system.
  • Find which printer is causing the problems. Use transaction SP01 System |Services | Output Controller. Check the output request attributes, the log files, and the size of the print job.
  • For remote printers, check the network connection.
  • If a print job has been printed out but contains unreadable characters, check whether the device type is the most appropriate, whether the printer is working in emulation mode, and what the access method is for the device.
  • When nothing is output at the printer and the output controller is in wait status, check the system developer traces and the system log and look for time-out messages. Check that all application servers running spool work processes are reachable.
  • If the job has status Complete or Problem and nothing is output at the physical printer, it might be related to a wrong output device definition, a problem in the host spooler, the physical printer, or the SAPLPD transfer program. Carefully check the access method.
  • If printing is very slow, possible causes might be lost indexes in the spool tables, too many spool table entries, slow WAN connections, or incorrectly defined access methods. Often you will need to review the printing strategy about distribution of output devices in several application servers according to their expected volume and size of print jobs. Refer to the SAP online documentation and the SAP Service Marketplace about some interesting planning strategies for the spool system. As an additional analysis method, carefully check the spool profile parameters.

SAP Printing System Administration Tasks

The SAP printing system and associated tasks are a subset of those general administration tasks for the daily operation of the SAP system. SAP system managers should be in charge of the following tasks:

  • Periodically checking and monitoring the spool system, both at SAP and at the operating system level. Use the CCMS and workload monitor to check the spool work process performance.
  • Deleting old spool requests or scheduling the background job which automatically deletes them.
  • Defining new printers, device types, and other device elements.
  • Using the statistical information of the system for fine-tuning the planning strategy.
  • Troubleshooting the spool system.

From the initial Spool Administration screen, there is a pushbutton in the lower part of the screen, within the Administration box, which can be used to check the consistency of the spool system. Call this function by clicking on the Consistency Check of Spool Database pushbutton.

Spool System Instance Profile Parameters

To display the instance profile parameters directly related to the spool system, from the initial Spool Administration screen, select Utilities | Display SAPPARAM. If you need to change any of these parameters, use the profile maintenance functions available within the CCMS.

Display of the instance parameters for the spool system

Display of the instance parameters for the spool system


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