# DIGITAL TCP/IP Services for OpenVMS
User's Guide

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Logical NOT (| --)

VT100: EXT + N | VT200: EXT + N
DEFINE_KEY Function: (None)

Represents the remote host's symbol for a logical NOT; displayed as a circumflex ( ^ ) on DIGITAL terminals.

Logical OR (|)

VT100: EXT + O | VT200: EXT + O
DEFINE_KEY Function: (None)

Represents the remote host's symbol for a logical OR; displayed as a solid vertical line from the terminal's graphics set. Press Ext + O if the vertical bar is not available on your keyboard.

New Line (Hooked left arrow)

VT100: Return | VT200: Return
DEFINE_KEY Function: NEWLINE

Moves the cursor to the first unprotected position on the next line of your screen. If no unprotected fields are on the screen when you invoke the new line function, the cursor moves to the first location on the screen. If the screen has no fields, this key has the same function as the Return key on DIGITAL terminals.

NUM OVR (numeric lock override)

VT100: EXT + J | VT200: Remove
DEFINE_KEY Function: NUMOVR

Lets you enter nonnumeric characters into numeric fields. Once you enable this function, use NUM OVR again to disable it. If you do not disable the numeric lock override, it remains enabled even after you exit from TN3270. The letter O appears on the status line to indicate that the numeric lock override is in effect.

PA1, PA2, PA3

VT100: PF4 , KP- , KP, | VT200: PF4 , KP- , KP,
DEFINE_KEY Function: PA1--PA3

These program access keys are defined by the program you are using. These keys request attention from the remote application program without sending any data. You should refer to the user's guide of your application program to learn how the PA keys are defined.

PF1 through PF24

VT100: see below | VT200: see below
DEFINE_KEY Function: PF1--PF24

These program function keys are defined by the remote application program you are using. They request attention from the application program and send the data entered to the host. The PF keys are coded by the application program to perform functions relating to the application. A particular PF key may be coded differently from one application to another. The user's guide of the remote application program usually defines the specific PF key assignments for that application program.

To Implement This Function | Press This Key or Key Combination
--- | ---
PF1 | PF1
PF2 | PF2
PF3 | PF3
PF4 | KP7
PF5 | KP8
PF6 | KP9
PF7 | KP4
PF8 | KP5
PF9 | KP6
PF10 | KP1
PF11 | KP2
PF12 | KP3
PF13 | EXT + PF1
PF14 | EXT + PF2
PF15 | EXT + PF3
PF16 | EXT + KP7
PF17 | EXT + KP8
PF18 | EXT + KP9
PF19 | EXT + KP4
PF20 | EXT + KP5
PF21 | EXT + KP6
PF22 | EXT + KP1
PF23 | EXT + KP2
PF24 | EXT + KP3

PLAY

VT100: EXT + M | VT200: Insert Here
DEFINE_KEY Function: PLAY

Recalls keystroke sequences stored on PF keys using the RECORD function. Invoke the PLAY function and then press the PF key on which the desired key sequence is stored. The PLAY function executes all commands included in the keystroke sequence.

If the HELP utility is invoked in your key sequence, the PLAY function continues until you exit from the HELP utility. Also, if you use functions that require you to respond to prompts (such as ATTACH, DEF KEY, SET FIL, or SPAWN), the information you type at the prompt is not recorded. When you recall the sequence, the system prompts you for this information again.

P appears on the status line if the status display is enabled.

PRINT

VT100: EXT + P | VT200: F11
DEFINE_KEY Function: PRINT

Records the contents of your screen in a file or at a printer. (This is a local print feature.) If the status display is enabled when you use the PRINT function, the word Print appears on the status line. Your screen refreshes when the printing process completes.

The first use of PRINT in a given run of TN3270 creates a new version of the output file. Successive uses of PRINT in the same program cause the screen contents to append to the existing file. If the output is directed to a printer, each use of PRINT creates a separate entry in the printer queue. If the printer is a spooled printer, the output is released for printing immediately.

Use the command qualifier /PRINTER=file to specify where to direct the output file. The SET FIL function allows you to change the name of the output file each time you invoke the PRINT function.

RECORD

VT100: EXT + L | VT200: EXT + Insert Here
DEFINE_KEY Function: RECORD

Saves a keystroke sequence on a specific PF key. Invoke the RECORD function with the appropriate key sequence (as described above), press the PF key as prompted, enter the keystroke sequence, and then invoke the RECORD function again. You can save a maximum number of 127 keystrokes on each PF key. If the status display is enabled when you use the RECORD function, the letter R appears on the status line.

To recall the keystroke sequence, use the PLAY function. Use the DV CNCL function to cancel the RECORD function. To erase all previously recorded key sequences, use the ER INP function.

REFR (refresh)

VT100: Ctrl/W | VT200: Ctrl/W or F20
DEFINE_KEY Function: REFRESH

Removes TN3270 error messages, operating system messages, or other messages that appear on your screen. This key function deletes extraneous characters from your screen and redisplays the fields and data that were on the screen before the interruption.

This function does not transmit or receive data from the remote host. It is a local OpenVMS function.

RESET

VT100: KP0 | VT200: KP0
DEFINE_KEY Function: RESET

Returns the keyboard to normal input mode from insert mode. Also, the RESET function returns the keyboard to your control after it locks when you try to enter data into a protected or a full field, or when you try to enter the wrong type of data into a field.

Invoking RESET turns off the Inhib indicator. The cursor remains where it is and the screen remains unchanged.

SELECT

VT100: EXT + K | VT200: Select
DEFINE_KEY Function: SELECT

Lets you choose items from a menu, table, or list and then notify the program of your selection. Use the arrow keys to position the cursor on the field designator character, then use the SELECT function. For more information on using SELECT, refer to the user's guide of the remote application.

SET FIL (set print file)

VT100: EXT + F or Ctrl/F | VT200: EXT + F11
DEFINE_KEY Function: SET_PRINTFILE

Lets you change the name of the file or device that receives output each time you invoke the PRINT function. After you invoke SET FIL, you are prompted for the name of a new output device, emulating the remote host's IDENT function.

Note that if you specify the same name that is already in use, subsequent PRINT operations direct output to a new version of the same file.

SHO MSG

VT100: EXT + G | VT200: EXT + F14
DEFINE_KEY Function: SHOW_MESSAGE

Displays the broadcast messages that have been posted on a separate screen. If the status line is enabled, Msg appears on the status line. If you do not read the messages before they fill up the screen, the messages begin to scroll up out of view and you will no longer be able to read them. These broadcast messages are not saved after you read them or exit TN3270.

SPAWN

VT100: EXT + D | VT200: Find
DEFINE_KEY Function: SPAWN

Creates a subprocess under the current process. Use the LOGOUT command to terminate the subprocess. Because a tree of subprocesses can be established using the SPAWN function, you must be careful when terminating any process in the tree. When a process is terminated, all subprocesses below that point in the tree are terminated automatically.

When you create a subprocess, you can specify an optional command string. The command string is executed within the created subprocess and the subprocess terminates upon completion of the command.

STATUS

VT100: EXT + S | VT200: F17
DEFINE_KEY Function: STATUS

Lets you enable and disable the display of status information.

When you enable STATUS, the last line on your screen is painted over with a reverse video strip. This line may conceal remote host system or application information. If this occurs, Hidden appears in the status line.

Disable the status display by using the STATUS function again.

SYS REQ (system request)

VT100: EXT + R | VT200: EXT + F19
DEFINE_KEY Function: SYS_REQUEST

Lets you shift between the application program (the LU-LU session) and the control program (the SSCP-LU session). If the status display is enabled, Appl or SSCP appears on the status line to indicate the type of session. Appl appears when you are in an LU-LU session and SSCP appears when you are in the SSCP-LU session.

The screen is refreshed when you use the SYS REQ function.

Tab (Right arrow |)

VT100: Tab | VT200: Tab
DEFINE_KEY Function: TAB

Moves the cursor to the first character location of the next unprotected field on your screen. If the screen has no fields, the Right arrow | function moves the cursor to the first location on the screen.

If the cursor is within the last unprotected field on the screen, the cursor moves to the first position of the first unprotected field on the screen.

Vertical Control (Up arrow and Down arrow)

VT100: Up arrow or Down arrow | VT200: Up arrow or Down arrow
DEFINE_KEY Function: UP, UP_NOWRAP, DOWN, or DOWN_NOWRAP

Moves the cursor vertically on your screen without altering the data you have already entered.

If the cursor is at the:

- Top of the screen when you press the up arrow, the cursor appears in the same column at the bottom of the screen
- Bottom of the screen when you press the down arrow, the cursor appears in the same column at the top of the screen
  If the screen display you receive is larger than 24 rows deep, you can use the Up arrow and the Down arrow keys to move through the display. These keys scroll the screen display up or down.
  If you want the cursor to wrap to the opposite edge of the display, use the key sequence EXT + Up arrow or EXT + Down arrow.

### 5.12.9.1 Associated Documentation

For additional information about TN3270 key functions, see the following IBM documents:

- IBM 3270 Information Display System, Order No. GA23-0060
- IBM 3270 Information Display System: Operator's Guide, Order No. GA27-2742
- IBM 3270 Information Display System: 3278 Display Station Operator's Guide, Order No. GA27-2890-4

## 5.12.10 Redefining Your Keyboard

You can reassign functions and keys.

### 5.12.10.1 Functions You Can Redefine

You can redefine the following functions:

- All emulated functions
- Most IBM 3270 model functions
- All emulated alphanumeric and graphic characters

### 5.12.10.2 Keys You Can Define

The keys you can define are listed in Table 5-6.

Table 5-6 TN3270: Definable Keys
Location | Key Name
--- | ---
Function keys (VT100 and VT200) | PF1--PF4
Application keypad (VT100 and VT200) | KP0--KP9 ENTER MINUS COMMA PERIOD
Top-row function keys (VT200) | F6--F20 HELP (F15) DO (F16)
Editing keypad (E1--E6) (VT200) | FIND (E1) INSERT_HERE (E2) REMOVE (E3) SELECT (E4) PREV_SCREEN (E5) NEXT_SCREEN (E6)
Cursor keys (VT100 and VT200) | UP DOWN LEFT RIGHT
Control keys (VT100 and VT200) | Ctrl/A--Ctrl/Z, including: Ctrl/H (BS) Ctrl/I (HT) Ctrl/J (LF) Ctrl/M (CR) Excluding: Ctrl/Y---Interrupt Ctrl/C---Cancel/interrupt Ctrl/O---Output off/on Ctrl/S---Suspend output Ctrl/Q---Resume output

### 5.12.10.3 Keys You Cannot Define

You cannot redefine the following DIGITAL-reserved keys:

- Ctrl/Y --- Interrupt
- Ctrl/C --- Cancel/interrupt
- Ctrl/O --- Output off/on
- Ctrl/S --- Suspend output
- Ctrl/Q --- Resume output
- F1--F5

### 5.12.10.4 Redefining Keys

To redefine a keyboard key, use either of the following methods:

- Create a key definition file, a text file with individual key definitions in the form of DEFINE/KEY statements and DELETE/KEY statements (see Section 5.12.10.5).
- Use the DEF KEY function (see Section 5.12.10.6).

The following example establishes a TELNET/TN3270 connection to host JUNCO. By default, the terminal functions as if it were an IBM-3278-2 model terminal. It uses your customized keyboard definition file NEW_KEYS.DAT.

    $ TN3270 JUNCO /KEY_DEFINITION=NEW_KEYS.DAT

### 5.12.10.5 Creating a Key Definition File

Use the DEFINE/KEY and DELETE/KEY statements to create your own key definition file as described in the following sections.

DEFINE/KEY Statement

The DEFINE/KEY statement assigns a new function to a particular key. Its format is:

    DEFINE/KEY [/STATE=EXTEND] key_name function

/STATE | Optional. Default: non-extend mode. Redefines the key in extend mode.
key_name | Standard key name on the DIGITAL terminal.
function | TN3270 function you want mapped to this key.

You can define most of the named keys both in normal (non-extend) mode and in extend mode.

You can define the control keys (and the synonyms for them) only in normal mode. Do not specify the qualifier /STATE=EXTEND.

The following example assigns the EXIT function to the key sequence EXT + Z :

    DEFINE/KEY/STATE=EXTEND "Z" EXIT

DELETE/KEY Statement

The DELETE/KEY statement removes the function assigned to a particular key. Its format is:

    DELETE/KEY [/STATE=EXTEND] key_name

/STATE | Optional. Default: nonextend mode. Deletes the key in extend mode.
key_name | Standard key name on the DIGITAL terminal.

Example:

The following example removes the default value of EXIT from Ctrl/Z.

    DELETE/KEY [Ctrl/Z]

Key Definition File: Example

By default, TN3270 maps 3270 functions to the numeric keypad.

The following example shows key definition statements in a key definition file. The definitions restore the numeric keypad on a VT220 keyboard.

    DEFINE/KEY     KP0 "0"
    DEFINE/KEY     KP1 "1"
    DEFINE/KEY     KP2 "2"
    DEFINE/KEY     KP3 "3"
    DEFINE/KEY     KP4 "4"
    DEFINE/KEY     KP5 "5"
    DEFINE/KEY     KP6 "6"
    DEFINE/KEY     KP7 "7"
    DEFINE/KEY     KP8 "8"
    DEFINE/KEY     KP9 "9"
    DEFINE/KEY     period "."
    DEFINE/KEY     comma ","
    DEFINE/KEY     minus "-"
    DEFINE/KEY     Select extend
    DEFINE/KEY     Prev_screen reset

This example restores the key normally associated with the EXT function (KP.) as the keypad decimal point. When you assign a key another function, you remove its default value. Therefore, because some TN3270 functions rely on an EXT function, the EXT function is defined to correspond to the Select key. This example also restores the key normally associated with the RESET function (KP0) as the keypad 0 key. The example then defines the RESET function to correspond to the Prev Screen key.

### 5.12.10.6 Interactive Definitions: DEF KEY Function

Use the DEF KEY function to define or redefine a key interactively. Your new definition exists until you log out from the remote host or disconnect from it.

When you invoke the DEF KEY function, TN3270 displays a prompt in the status line at the bottom of your screen.

Example:

The following example shows the use of DEF KEY to define a key. You invoke the DEF KEY function by entering the Ctrl/K sequence, after which you are prompted for the key you want to define and the function to assign to that key.

    [Ctrl/K]
    Press the key that you want to define:

    Enter the function name or quoted character:

You can also use DEF KEY to remove an assigned function. A null reply to the following prompt removes the definition currently in effect for that key:

    Enter the function name or quoted character:

What you type during the DEF KEY dialog is subject to translation from the National Character Set to the DIGITAL Multinational Character Set.

You cannot redefine a key that exists on your National Character Set terminal if it lacks a DIGITAL Multinational Character Set equivalent.

## 5.12.11 TN3270 Problem Solving

During a TELNET session in which you have invoked TN3270, you might experience the following problems:

Problem

- The keyboard keys do not work properly.
- Messages, such as the status line messages, do not appear in reverse video.
- You receive a message indicating that your terminal is an unsupported model.
  You cannot use TN3270 on a VT131 model terminal that is running in block mode.

Solution for a VT100-Series Terminal

Use Set-Up mode to verify that your terminal is in ANSI mode. Issue the following command:

    $ SET TERMINAL /INQUIRE

Solution for a VT200-Series Terminal or a Terminal Connected to Either a DIGITAL Personal Computer or a Workstation

1. Use Set-Up mode to verify that your terminal is:
   - In ANSI mode
   - Set to VT100 or VT200 emulation mode
2. Check the Communications Menu:
   The terminal communications line must be set for 8-bit characters. To check, issue the following command:

       $ SET TERMINAL /INQUIRE

   Solution for a Terminal with a National Language Keyboard

   Ensure that your terminal is set up to correspond to your keyboard.

   Problem

   You receive a message indicating that the screen size (or the alternate screen size) specified by the remote host is too big.

   Solution

   Use Set-Up mode to change to a valid screen size (see Section 5.12.1).

   Problem

   You try to use the RECORD or PLAY function, but you get an error message indicating that you have a bad key sequence file.

   Solution

   The file that stores the recorded key sequence is incompatible with the current version of the software or is corrupted.

   Ask your system manager to do either of the following:

   - Correct UCX$RECSEQ.DAT in your SYS$LOGIN directory.
   - Delete UCX$RECSEQ.DAT.
     If the system manager must delete this file, rerecord all the key sequences you had stored on the PF keys.

   ## 5.12.12 Debugging Application Programs Using the IBM 3270 Model Terminal Emulator

   Visible attribute mode provides a way to debug application programs. After you use the DSP ATT (display attributes) function to enable visible attribute mode, all attribute characters are visible. Attribute characters are characters that appear at the start of a field to indicate the following information:

   - How the field appears on the screen:
     - At normal intensity
     - At high intensity
     - Invisibly
   - What type of data the application expects in the field:
     - Numeric
     - Alphabetic
     - Alphanumeric

   The following information shows:

   - How to enter and exit visible attribute mode (see Section 5.12.12.1).
   - The screen displays (see Section 5.12.12.2).

   ### 5.12.12.1 Entering and Exiting Visible Attribute Mode

   The displays described in this section rely on your terminal's ability to produce reverse video and bold characters.

   Invoking the DSP ATT function toggles in and out of visible attribute mode.

   - The first time you press this key combination:
     - The screen refreshes.
     - The attribute characters appear either in reverse video or underlined.
   - The second time you press DSP ATT:
     - You turn off this mode.
     - The screen refreshes and returns to normal mode.

   ### 5.12.12.2 Visible Attribute Mode Displays

   The attribute characters are displayed in reverse video, bold symbols. Attribute characters indicating numeric fields are also underlined. All other characters are displayed normally. Table 5-7 lists the attribute characters and their meanings.

   Table 5-7 Visible Attribute Mode: Displays
   Character | Meaning
   --- | ---
   n | Unprotected field with normal intensity follows
   N | Protected field with normal intensity follows
   d | Following unprotected field is light-pen-detectable
   D | Following protected field is light-pen-detectable
   h | Following unprotected field has high intensity
   H | Following protected field has high intensity
   i | Unprotected nondisplay field follows
   I | Protected nondisplay field follows

   # 5.13 Command Descriptions

   To start TELNET, issue either the TELNET command or the TN3270 command at the DCL prompt.

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