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ESCON Channel Attachment

Use attachment Feature Code 9970/4131 for AFCCU microcode level 11.x and earlier. Use attachment Feature Code 9631/6431 for AFCCU microcode level 12.0 and later.

When connected directly to an ESCON(R) channel, the printer can be a maximum distance of 3 kilometers (1.875 miles) from the channel. Either an IBM(R) 9032 or 9033 ESCON Director provides connectivity to additional host systems and also extends the maximum channel length as follows:

The Extended Distance Feature (XDF) on the 9032 or 9033 ESCON Director also extends the maximum channel length as follows:

The IBM 9036 ESCON Remote Channel Extender (Models 1 or 2) extends the interface across common carrier fiber optic connections. You can use one, two, or three 9036 extenders for a maximum distance of 43 kilometers.

The ESCON attachment is available on all Infoprint 4100 and 4000 models:

Figure 23 shows the details of the above connection options.

Figure 23. Serial channel attachment options
Serial channel attachment options

ESCON Multiple Host Environment

With ESCON, a single ESCON attachment can be shared between multiple LPARS or system images. However, the printer cannot be shared between multiple PSF hosts at the same time. Operational procedures must be put in place to take the printer off-line to the existing PSF host before bringing it on-line to another PSF. Otherwise, unpredictable print results can occur.

The printer ESCON configuration option for Multi-Host Environment insures that an operator cannot inadvertently vary the printer on-line to multiple PSF hosts simultaneously. This allows sharing of ESCON attachments without concern that operator error could cause print problems. Use of the Multi-Host Environment option requires support for printer ASSIGN and UNASSIGN in both the operating system and PSF. Operating system support is provided in OS/390(R) V1R3.0 (which may be VM guests) and higher. PSF support is provided in PSF 3.1.0 for OS/390 and higher, and also with APAR OW29992 to PSF/MVS 2.2. Do not enable the printer configuration option for Multiple-Host Environment unless all hosts connected to the printer support printer ASSIGN and UNASSIGN. Otherwise, PSF cannot access the printer.

To allow access by a different PSF host, the operator must drain the printer and vary it off to one host before varying it on to the second host. A second host trying to vary on the printer is denied access with a notice that the printer is assigned elsewhere. The printer cannot be successfully varied on to the second host until the operator drains and varies it off to the first host. For more information on PSF/MVS ASSIGN and UNASSIGN support, see PSF for OS/390 Customization, or the documentation for APAR OW29992 to PSF/MVS 2.2.