3270 printer emulation

When configuring 3270 printer emulation on i5/OS, you must decide which communications line protocol to use. The iSeries server supports both binary synchronous communication (BSC) and Systems Network Architecture (SNA) 3270 printer emulation. Therefore, the choice is normally dictated by the protocol supported by the zSeries server communications software and controller.

BSC 3270 printer emulation

BSC 3270 printer emulation can be used with any zSeries server that supports a 3274 control unit (Model 51C) in a BSC multipoint tributary network using a nonswitched line. BSC 3270 printer emulation supports the following features:

SNA 3270 printer emulation

SNA 3270 printer emulation enables the iSeries server to connect into any existing SNA 3270 network. Any printers attached to the system print information received from the zSeries server. The 3270 emulation session is linked to a printer file, which in turn is linked to a printer device. All 3270 printers are emulated as Logical Unit 3 printers with the exception of the 3287 and 3289 printers, which can be emulated as either LU1 or LU3 printers.

The difference between LU1 and LU3 printers is essentially the level of intelligence which the zSeries server expects to find at the printer device. If the printer is emulated as an LU1 printer, an LU-LU session can be established with the host. Depending on the host applications, such a printer would be able to fully support SNA character string (SCS) data streams sent to it. If the iSeries server printer emulates an LU3 printer, only an LU-PU session can be established between it and the zSeries server. This could cause unexpected results when using host print applications. For example, if the host application was expecting to communicate with an LU1 printer, the printed output would probably not be correctly formatted in terms of line spacing, page length, and so on.

For additional information about 3270 printer emulation, see 3270 Device Emulation Support Link to PDF.