Data that is displayed incorrectly

Suggestions on how to deal with incorrect data values, partially missing data, early data that is overlaid by later data and data that is formatted incorrectly.

Wrong data values are displayed

If the data values are wrong on the user’s part of the screen (the space above the area used to display status information to the operator), or in the hard copy produced by a printer, it is likely that the application is at fault.

Some data is not displayed

If you find that some data is not being displayed, consider these possibilities:
  • The SENDSIZE value for the TYPETERM definition could be too large for the device receiving the data. Its receiving buffer could then overflow, with some data being lost.
  • SCRNSIZE(ALTERNATE) might be specified in the PROFILE definition for the transaction running at the terminal, while default values for ALTSCREEN and ALTPAGE are allowed in the TYPETERM definition for the terminal.

    The default values for ALTSCREEN and ALTPAGE are 0 rows and 0 columns, so no data could then be displayed if SCRNSIZE(ALTERNATE) were specified.

  • EXTENDEDDS(YES) is specified for a device that does not support this feature.

Early data is overlaid by later data

Early data can be overlaid by later data, so that data appears in the wrong order, when the SENDSIZE value of the TYPETERM definition is too large for the device receiving the data. This is because the buffer can wrap when it is full, with the surplus data overlaying the first data that was received.

The data is formatted wrongly

Incorrect formatting of data can have a wide range of causes, but here are some suggestions of areas that can sometimes be troublesome:
  • BMS maps are incorrect.
  • Applications have not been recompiled with the latest maps.
  • Different numbers of columns have been specified for ALTSCREEN and ALTPAGE in the TYPETERM definitions for the terminal. This can lead to unpredictable formatting errors. However, you will not see them unless SCRNSIZE(ALTERNATE) has been specified in the PROFILE for the transaction running at the terminal.
  • The PAGESIZE values included in the TYPETERM definitions must suit the characteristics of the terminal, or you get formatting errors.

    For a screen display, the number of columns specified must be less than or equal to the line width. For a printer, the number of columns specified must be less than the line width, or else both BMS (if you are using it) and the printer might provide a new line and you will get extra spacing you do not want.

    The default values for PAGESIZE depend on the value you specify for the DEVICE keyword.

  • If you get extra line feeds and form feeds on your printer, it could be that an application is sending control characters that are not required because the printer is already providing end of line and end of form operations.

    If your application is handling the buffering of output to a printer, make sure that an “end of message” control character is sent at the end of every buffer full of data. Otherwise, the printer might put the next data it receives on a new line.