Remapping 3270 Field Attributes in Verastream Host Integrator

  • 7021306
  • 14-Aug-2015
  • 12-Mar-2018

Environment

Verastream Host Integrator version 7.7.32 (7.7 Hotfix 3) or higher

Situation

Certain 3270 host applications, especially if not running on IBM z/OS, may have display problems due to non-standard mappings on terminal attribute fields.

This issue is identified by the following symptoms:

  • When using the host application (in VHI or any 3270 terminal emulator), certain text does not display properly, such as:
    • Passwords display on the terminal screen when they should be hidden.
    • Text is hidden when it is expected to be visible.
    • Intensified text is displaying as normal text.
  • The host application may be a non-standard implementation of 3270 (TN3270E), such as running on a Tandem host instead of IBM System z.

Resolution

Beginning in VHI version 7.7.32, to enable and define field attribute remapping, define an operating system environment variable named VHI_3270_ATTR_REMAP.

The environment variable value is a string of attributes to remap. The string contains hex values being remapped, separated by an equal sign. Multiple semicolon-delimited remappings can be specified (up to a maximum of 64, which is the number of attributes defined by the 3270 standard). A trailing semicolon is optional.

Example:

Figure 1. Windows system variable VHI_3270_ATTR_REMAP is set to 00=0C;08=00;0C=08;1C=18;2C=28;3C=38;
Figure 1. Windows system variable VHI_3270_ATTR_REMAP is set to 00=0C;08=00;0C=08;1C=18;2C=28;3C=38;

In this example, 00 is mapped to 0C, 08 is mapped to 00, and so on.

Note the following:

  • Contact Technical Support for assistance with determining the remapping string. Typically, this requires capturing a datastream trace for analysis.
  • This environment variable must be configured on every system running VHI Design Tool or VHI session server that is connecting to the non-standard host. (You do not need to configure client systems running the connector only.)
  • After configuring the environment variable, restart the VHI session server service or Design Tool application.
  • On UNIX/Linux, you may need to export the environment variable so that it’s available to the process that runs VHI services.
  • The remapping applies to all 3270 sessions running in VHI.

Cause

By default, the VHI data stream processor expects the standard field attribute definitions as described in IBM 3270 Information Display System Data Stream Programmer’s Reference (GA23-0059-07), pages 4-13 through 4-14, and Table 4-4, Bit Definitions for 3270 Field Attributes. Host applications that do not follow the specification will exhibit display problems.

Additional Information

Legacy KB ID

This document was originally published as Attachmate Technical Note 10161.

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