Troubleshooting
Problem
This document describes the concurrent connection of IBM 5494 Twinax devices to multiple operating systems through an APPN Network.
Resolving The Problem
Definition of IBM 5494 Concurrent Host Attachment
When nonprogrammable (NWS) workstations, (displays and printers) that are connected to the IBM 5494 (using twinax) have sessions concurrently connected to different operating systems, these sessions can be on different devices or on the same device if the device is capable of multiple sessions (for example, a 3487, shared address display). For twinax-attached printers, this is called printer sharing.
With the 5494 and Concurrent Host Attachment, the 5494 connects to the primary operating system and does an under-the-covers SNA pass-through to the selected other operating system.
What Is Needed for 5494 Concurrent Host Attachment
| IBM 5494 with a System Diskette at Level 3.1 or later and Field 21 set to 1. | |
| Operating system: - Set for Node type = *NETNODE (run the DSPNETA command to check) - APPN SNA pass-through connection path available between the operating systems - If using a *LAN connection between multiple (greater than two) operating systems, for correct operation it is important that in each of the APPC controller descriptions used between the systems are set for the following (these are not the default settings): APPN minimum switched status (MINSWTSTS) = *VRYON Switched disconnect (SWTDSC) = *NO - On all operating systems to be used on Concurrent Host Attachment, set the SYSVAL QAUTORMT to '1' (YES). This allows the required RWS controller descriptions to be created as needed. - Ensure that in the token-ring or Ethernet line descriptions between the operating systems under Additional Parameters, the Autocreate Controller value is set to *YES. |
5494 Remote Control Unit User's Guide (GA27-3960-04 or later), Chapter 8 and Appendix C (Concurrent Host Attachment), starting on page C-66.
This can also be found on the following Web site, by selecting Documentation, User's Guide (Topic 8, and C.10):
5494 Notes
The 5494 has some additional fields that must be configured for Concurrent Host Attachment.
| Field 20 = | Primary operating system - (Which one of the defined operating systems is to be used as the Primary system). This is the system that the 5494 gets its PTFs from and report its errors back to. |
| Field 21 = | Concurrent Host Attachment - This must be set to 1 (Yes) |
| Field 22 = | Concurrent Host Attachment Printer Time-out - If planning to use printer sharing, this value must not be 0 (zero)--suggest using 030 (30 seconds). This value is the time that needs to pass between the time one operating system printer writer is ended and another printer writer can be started (on this operating system or on a different operating system). If you are planning to have multiple printers at the remote 5494 site and would like Printer 1 to connect to OS/400 #1, and Printer 2 to connect to OS/400 #2, and so on, Field 22 should be set to 000 (disable printer time-out). Refer to the 5494 User's Guide, Chapter 8 section about Concurrent Host Attachment with Printer Sharing Disabled, to see how to use a display to assign each printer to a specific operating system. |
| New | Example 1 Two operating systems connected using token-ring with a 5494 connected via a SDLC nonswitched line to AS/400 WEST. |
| Example 2 Three operating systems connected using token-ring with a 5494 connected to the same token-ring LAN (local or WAN). |
Historical Number
14212059
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Document Information
Modified date:
18 December 2019
UID
nas8N1019658