BARR/3270 manual

6. Tuning Data

Since the default values for the options in this section work for most customers, most readers can go on to the next chapter, Start-up Instructions. If you have sophisticated applications or are experiencing problems, look over this chapter to see the variety of tuning parameters available.

Select Tuning Data.

Select the desired parameter. Explanations of each appear below.


6.1 Edit ASCII and EBCDIC Translation Tables

On the PC, characters are coded using the ASCII coding system. The IBM mainframe uses the EBCDIC coding system. To send files from the PC to the mainframe, the characters must be translated from the ASCII to the EBCDIC coding system. Coming from the host to the PC, characters must be translated from EBCDIC to ASCII. See Appendix B for a complete description of these tables.

Select translation mode (see the following descriptions).

Translate control codes to Control codes

Select Translate control codes to Control codes if you want to use control characters to exercise special features of your printer. For example, the Printronix printer uses Escape sequences to print boldface and enlarged characters. See Appendix B for the full translate tables. The Translate control codes option alters the entries 00 to 1F of the ASCII-to-EBCDIC table and entries 00 to 3F of the EBCDIC-to-ASCII table to agree with the tables in Appendix B.4 and Appendix B.5, respectively.

Translate control codes to Question marks

Translate control codes to Question marks option converts all control codes to ?. The Translate control codes to Question marks option changes the entries 00 to 1F of the ASCII-to-EBCDIC table and entries 00 to 3F of the EBCDIC-to-ASCII table to question marks.

Choose Language for translation tables

This feature allows you to modify the ASCII-to-EBCDIC and EBCDIC-to-ASCII translation tables for use with native language character sets. When you use code pages other than standard ASCII and EBCDIC, you must change the tables to translate the native language characters correctly.

  1. Select the ASCII code page used on your PC. This is done using DOS (version 3.3 or later); consult the chapter in your DOS manual on Code Page Switching. For the U.S. English character set, use ASCII code pages 437 (US) or 850 (multilingual); for all other character sets, use ASCII code page 850. Code page 437 is the default for most machines. While you are installing code page switching, you may also want to install keyboard support for your character set; this is described in your DOS manual.

  2. From the Installation Description screen, select Tuning Data. Select Edit ASCII and EBCDIC Translation Tables.

  3. Select Choose Language for translation tables.

These choices correspond to EBCDIC code pages, as given in IBM publication GA23-0061, IBM 3270 Information Display System—3274 Control Unit Description and Programmer’s Guide, Appendix D: APL/Text Feature. Barr’s list of languages and translation standards will be changed as new international standards emerge.

  1. Select the language used by your host application and press ENTER. For English, there are two selections; choose the one that matches the ASCII code page installed on your PC. All other languages require ASCII code page 850.

  2. After you have made your selection, you should see the message:

The translation tables have been modified for language "Austrian/German (Alternate)".

You can select "Edit translation tables" to see these changes or to make additional changes.

Edit translation tables

If you need to use one of the first three options (Translate control codes to Control codes, Translate control codes to Question marks, or Choose Language for translation tables), you must do so before entering Edit translation tables; otherwise, your editing of the translation tables will be altered.

Only in rare circumstances will you need to edit the tables. For example, the program may need adjustment to adapt to a printer that does not print lowercase letters.

The Edit translation tables option displays the ASCII-to-EBCDIC table and two EBCDIC-to-ASCII tables for editing.

Select Edit translation tables. The ASCII-to-EBCDIC translation table appears on the screen.

Use arrows to move about the screen. Edit.

Press ENTER to display the next table. The EBCDIC-to-ASCII Table one will appear. Edit.

Press ENTER. The EBCDIC-to-ASCII Table two will appear. Edit.

Press ENTER.

Assign translation tables to devices

With this selection, you can assign different EBCDIC-to-ASCII tables for each print or punch stream. For each device, choose Table one or Table two.

Choose Table one or Table two.

6.2 Printer Control

Printer Control specifies the format of printed output.

Make selections.

Maximum print position:

The default of 255 print characters can be customized for your application. For example, to start a new line when the line received is over 132 characters long, specify:

Maximum print position: 132

Printer error timeout in minutes:

Wait time in minutes before a printer error condition is reported to the host. Default time is set to 10 minutes. Allows the operator time to notice and correct printer problems.

6.3 Additional Parameters

Additional Parameters disable features and describe hardware configurations.

Type or select choice.

Memory allocated for buffers:

This memory refers to that allocated for buffers and working storage. If this value is larger than the amount of memory available on the machine, then BARR/3270 will use as much memory as is available. If this parameter is made very large, you may have too little room to run DOS simultaneously. This parameter does not take effect until the next time you run BARR/3270.

Number of minutes before screen save:

Since many 3270 workstations run 24 hours a day, the screen life of the monitor may be shortened. For example, if this parameter is set for 10 minutes, the screen clears after 10 minutes. Pressing any key will turn it back on. This time limit does not interfere with normal operation of BARR/3270. This feature only works with some adapter cards such as IBM CGA, IBM monochrome, IBM PS/2 VGA; it does not work with the IBM EGA adapter.

Disable Installation Description?

No Retain the Installation Description screens.

Yes Remove the Installation Description screen to prevent re-installation of the program. BARR/3270 will not display commands sent at startup. This is a security feature that hides passwords. You should make a backup copy of BARR/3270 before disabling installation.

Disable Receive mode in Assign Devices?

No Default.

Yes Remove Receive Mode from Assign Devices screen.

Fast scroll used on CGA color monitor adapter?

No The screen blinks each time new data are scrolled onto the screen. This is slower.

Yes The screen scrolls fast without blinking. Will cause snow if used with an IBM color adapter.

Initial session is?

OPER Default. BARR/3270 goes into the Operations session.

DOS BARR/3270 goes into the DOS session.

Session1-Session4 Applies only to 3270 option.

DOS session executes AUTOCMD.BAT?

No Default.

Yes When you enter DOS from BARR/3270, AUTOCMD.BAT is immediately executed. This is convenient to go directly to an applications program.

Hot key uses?

This option allows you to choose an alternate hot key to use during your BARR RJE session. Possibilities are:

Ctrl-Alt (Default)
Ctrl-Shift
Alt-Shift

Press ENTER to return to Tuning Data screen.

6.4 Modem and Line Control (SDLC)

Modem and Line Control provides options for controlling communications.

Type or select choice.

Communications speed when using synchronous modem eliminator cable:

This is applicable when using a synchronous modem eliminator cable (see the BARR Adapter manual).

Constant RTS?

No Default. Request-To-Send is a signal that BARR/3270 RJE uses to tell the modem it wants to send data. The modem returns a Clear-To-Send signal when it is ready for BARR/3270 to send data.

This parameter must be No for half-duplex lines.

Yes Request-To-Send signal is always set on—even at times BARR/3270 is not sending data.

Some full-duplex modems do not function when this parameter is set to No. Do not select Yes for multipoint lines.

Start communications at time:

You can take advantage of lower telephone rates by entering a specific time to begin communications. If you do not specify a time and are using an autodial modem, communications begin immediately. If the time to start communications is within the past eight hours, BARR/3270 will immediately start the dial-up procedure. The time you enter to begin communications will be displayed above the Operation screen. This feature can also be requested from the autodial connection screens in Modem Type and Dialing Instructions.

The time should be defined in the 24-hour scheme. For example, 7:00 p.m. is 19:00, and 12:00 a.m. is 00:00.

Ignore DSR=0?

No Default. Begin communication if Data-Set-Ready line is a 1.

Yes Ignore the Data-Set-Ready line.

Drop DTR on exit?

Yes Default. Data-Terminal-Ready will be dropped after BARR/3270 exits. This causes the modem to hang up the telephone.

No Dial: Maintain telephone connection after BARR/3270 exits. This allows the connection to be re-established without having to redial the telephone. This feature is useful when you want to exit BARR/3270, run another program, and return to BARR/3270 without redialing. Dedicated line with Synchronous Modem Eliminator cable: The host will try to maintain connection after program is exited. Restarting BARR/3270 will not require mainframe operator action.

Communication role?

You can force the communication role of your computer to be the host site or the remote site.

Possible selections are:

Remote Default. BARR/3270 will assign your PC as the remote site.

Host Not applicable.

Minimum number of LU:

When BARR/3270 is operating in Host mode, this option forces at least this number of units to be activated.

Maximum number of LU:

This parameter limits the number of logical units that BARR/3270 will activate. It is a seldom used parameter.

Line trace buffer size:

The line trace buffer records the most recent data link control frames. The line trace, which is included in the memory dump, is useful for resolving communications problems. Reducing the size of the line trace buffer reduces the time period that can be recorded but saves memory. Buffer size can range from 0 to 64,000; the default value is 32,000.

Press ENTER to return to the Tuning Data screen.

6.5 Restart Actions

The Restart Actions screen displays options for restarting the BARR/3270 program.

Type or select choice.

Disconnect if idle?
Idle time period:

No Do not disconnect when communications line is idle.

Yes Idle time period is only valid if Yes is selected. BARR/3270 will automatically disconnect if the communications line is idle for the disconnect idle time period. Thirty seconds is the normal time period. The disconnect idle time period is the number of seconds before an idle communications condition will be declared. See Section 8.2 for the Disconnect then Exit to DOS option.

Exit from BARR/3270 on restart conditions?

No Restart conditions are in effect; BARR/3270 will not exit to DOS.

Yes In several situations where BARR/3270 would restart itself, it will instead exit to DOS. Exceeding the time-out limit and receipt of DLE-EOT are two of these conditions.

Press ENTER to return to the Tuning Data Screen.