This chapter takes you step by step through a 3270 session.
From the Operation screen, Select Advanced.
Select Sessions.
Select the 3270 session you want to work in. For example, choose Session 1.
The 3270 screen is shown below:
BARR’s on-line keyboard help screen makes a keyboard map template unnecessary.
To display the help screen from anywhere in a 3270 session, enter Ctrl-F2.
The help screen lists the standard 3270 keys as well as some special function keys unique to the BARR software. You can execute a 3270 key from a 3270 session screen in two ways:
by pressing the PC key(s) mapped to the 3270 key
by selecting the 3270 key from the help screen.
The action of most of these keys (PF1-Cursor Sel, Insert, Delete) is documented in greater detail in the manual IBM 3270 Information Display System: 3274 Control Unit Description and Programmer’s Guide.
PF1-PF24
Program Attention Keys. Send an Attention Identifier (AID) character to the host identifying which key is pressed. The host program takes appropriate action for the key pressed.
PA1-PA3
Program Attention Keys. See above.
Enter
Program Attention Key. Usually accompanies data entered at the terminal by the operator.
Clear
Program Attention Key. Also clears the entire display terminal screen to nulls.
Sys Req
Allows switching from the LU-LU session to the SSCP-LU session and vice-versa.
Test
Invokes the 3274 resident test functions.
Cursor Sel
Allows the Selector Light-Pen detection function to be performed from the keyboard.
Attn
Sends status information to the host application program.
Dup
Duplicate. Enters a unique character on the display, then goes to the next unprotected field on the screen. This character provides information to the Application Program that the same operation is indicated for the rest of the field in which it is located.
Field Mark
Enters a unique character on the display. This character informs the host Application Program of the end of a field in an unformatted buffer or the end of a subfield in a formatted buffer.
→ (Tab)
Moves the cursor to the first character location of the next unprotected data field.
← (Backtab)
Same as Tab, but in the reverse direction.
Newline
Move the cursor to the first unprotected character location of the next line.
Home
Moves the cursor to the first unprotected character position on the display screen.
EraseEof
When the cursor is in an unprotected data field, this key sets to nulls all the character locations from the cursor to the end of the field. If the cursor is on a field attribute or in a protected field, this key locks the keyboard, inhibiting input.
EraseInput
Clears all the unprotected character locations on the display screen to nulls and repositions the cursor to the first unprotected location on the screen. If all the character positions on the screen are protected, then the cursor is repositioned on row 1, column 1.
Reset
Allows recovery from an input-inhibited condition by unlocking the keyboard.
AltCursor
Changes an underscore cursor to a block cursor, or the block cursor to an underscore cursor.
(Cursor) Blink
Pressing this key causes the cursor to stop blinking. Pressing the key again causes the cursor to blink. On the PC, this key only functions when you have a block cursor.
Key Click
By pressing this key, clicking sounds may be produced as keys are pressed on the keyboard. If key clicking is already activated, pressing this key turns off the clicking.
Insert
Turns on Insert mode.
Delete
Deletes a character at the cursor position.
In addition to standard 3270 key functions, BARR/3270 has several extra features you will find useful during a 3270 session. Instructions on the available commands are given in this section.
The Save Scr option on the Help screen allows you to save selected screens to a disk file. When you execute the command, the file screen.dat will be created if it does not already exist. If screen.dat does exist, each screen you select will be appended to the file.
To use the Save Scr option, Display the screen you want to capture to disk.
Select the Save Scr function from the Help screen or enter the PC key combination to execute the command.
The selected screen will be written to disk.
The Record Scr feature on the Help screen lets you save a series of consecutive screens to a disk file. When you use Record Scr, all screens that display during your 3270 session will automatically be captured to disk until you disable the option. This feature is especially useful for capturing screens that need to be included in documents. Captured screens are appended to the file named screen.dat. If the file does not exist, it will be created.
To enter:
Select the Record Scr function from the Help screen or enter the PC key(s) to execute the command.
Display each of the screens you want to capture to disk.
To exit:
Select the Unrecord Scr function from the Help screen or enter the PC key combination again. Record Scr is a toggle function: you select the option to activate it, and then select it again to disable it.
The Help Notes option on the keyboard help screen shows information about other keys used during a 3270 session.
To display the Help Notes, Select Help Notes.
The topics displayed on the Help Notes screen are discussed below.
3270 keyboard mappings:
Several keys which are on the keyboard of a 3270 terminal, such as the not symbol (¬), do not appear on the PC keyboard. These keys and their PC mappings are listed under 3270 Keyboard Mappings on the Help Notes screen. The mappings for these keys cannot be altered.
To exit program:
The Help Notes screen lists the steps to follow when you are finished with your 3270 sessions and are ready to exit the BARR/3270 program.
Cursor and Scroll control:
Cursor and scroll keys can be used during a 3270 session to position the cursor or scroll text up, down, left or right.
The Reveal facility displays the attributes of a field and null locations on the 3270 screen. The field attributes display in the left corner of the OIA line when the cursor is positioned on that field. As you move the cursor, these values are updated.
To enter:
Select the 3270 Reveal command.
Once in Reveal mode, the session proceeds normally. If an error occurs, the original OIA line showing the error condition will display. After a few moments, the field attribute indicators are restored.
To exit:
Select Reveal again.
Reveal is a toggle function: entering the Reveal command when Reveal mode is active restores the screen to normal.
Reveal Attribute Legend
|
UNPROT |
Unprotected. A field that can be modified. |
|
PROT |
Protected. A field that cannot be modified. |
|
ALPHA |
Alphanumeric. Any letter, number or symbol. |
|
NUM |
Numeric. Symbols: 0123456789,.+-$ |
|
DISP |
Displayable field. |
|
Non-DISP |
Non-displayable field. Field is displayed as blanks. |
|
Int-DISP |
Intensified display. |
|
SPD |
Selector Light-Pen Detectable. |
|
Non-SPD |
Not Selecter Light-Pen Detectable. |
Select File Transfer.
The use of these functions is discussed in detail in Chapter 11, File Transfer.
The Quit option allows you to disconnect and exit BARR/3270 from a 3270 session.
With BARR software, during a 3270 session you can emulate all the terminal model types specified in the 3270 Description. You need to indicate to the host the terminal type you want to emulate by sending a LOGMODE on the Systems Operator (SSCP) session. See Appendix D for a list of LOGMODEs for the different terminal model types.
For example, suppose a Model 5 (28x132) terminal is specified in the 3270 Description and the name of the host application is MYTSO. This enables you to emulate the terminal model types 2, 3, 4, 5 in the 3270 session. To emulate a terminal model type 4:
Type the following string in the SSCP-LU session
MYTSO LOGMODE=D4C32784
Press ENTER.