Browse Prior Art Database

Enhanced Operator Error Processing by a Work Station Controller

IP.com Disclosure Number: IPCOM000122218D
Original Publication Date: 1991-Nov-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 3 page(s) / 126K

Publishing Venue

IBM

Related People

Eagen, ST: AUTHOR [+3]

Abstract

A work station controller (WSC) provides attachment of multiple non- programmable terminals (NPTs) to a host computer system. This article describes how a WSC can automatically request textual operator error information from the host processor for a WSC detected operator error and place that information in a WSC generated window. Also, the WSC can place host application-defined textual information for an application-detected data entry error in a WSC-generated window.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 49% of the total text.

Enhanced Operator Error Processing by a Work Station Controller

      A work station controller (WSC) provides attachment of
multiple non- programmable terminals (NPTs) to a host computer
system.  This article describes how a WSC can automatically request
textual operator error information from the host processor for a WSC
detected operator error and place that information in a WSC generated
window.  Also, the WSC can place host application-defined textual
information for an application-detected data entry error in a
WSC-generated window.

      The flow of a display data stream between a host processor and
a WSC and NPT commands between a WSC and an NPT are shown in the
figure.

      An outbound display data stream (host to WSC) is used by an
application or the host operating system to define a display panel
for an NPT.  An outbound data stream could contain a Write Error Code
(WEC) command which contains one line of textual information on some
type of user error.  An inbound display data stream typically
identifies the keystroke which caused the inbound data stream and any
modified entry field data.  The WSC communicates with the NPT by
sending commands (for example, write to screen, move the cursor, or
move screen data).  The NPT communicates with the WSC by sending user
keystrokes.  Note:  Programmable Work Station (PWS) users can run the
same host applications as NPT users when the PWS supports the same
display data stream as the above WSC and the PWS emulates the
combination of the WSC and NPT.  This article applies to a PWS
implementation as well as a WSC implementation.

      Previously, WSCs presented a 4-digit operator error code on the
last line of the display screen when a keystroking error was detected
(for example, non-numeric data in a numeric-only field).  The
operator error code identified the specific keystroking error.  If
the user did not recognize the error code, the user pressed the Help
key and the following sequence took place:
-  The WSC locked the keyboard, so the user could not reset the
operator error,
-  The WSC sent a request to the host for additional information on
the operator error (Help key identifier),
-  The host sent a WEC to the WSC which contained a one-line textual
operator error description,
-  The WSC overwrote the 4-digit error code with WEC data on the last
line of the screen, and
-  The user could then press the Reset key to remove the operator
error description and unlock the keyboard, or press the Help key
again, which led to more general help text (usually full-screen).

      Similarly, application programs perform data validation on
entry field data (for example, a menu may have 7 choices where only
values of 1 - 7 are valid).  If a data entry error was found, the
application would typically position the cursor in the entry field in
error and send a WEC with a description of the data entry error.  The
WSC would then write the WEC data to the last line...