HP Data Entry and Forms Management System (VPLUS) Reference Manual (32209-90024)

Appendix G 613
TERMINAL INFORMATION
VTURNON/VTURNOFF
cstatus Set to zero.
language Set too code that identifies the programming language of
the calling program.
comarealen Set to total number of 2-byte words in comarea .
VTURNON may set the following
comarea fields.
cstatus Set to nonzero value if call is unsuccessful.
fileerrnum Set to file error code if there is an MPE file error.
filen Set to MPE file number of terminal.
identifier Set to appropriate VPLUS terminal ID.
lab'info Set to appropriate number and length of labels.
Discussion
VTURNON is normally used in an application when the terminal has already been opened by
VOPENTERM and VTURNOFF was called to switch out of VPLUS block mode. VTURNON switches
the application back to VPLUS block mode without disturbing the image on the terminal
screen.
After a VTURNON, you must perform a VSHOWFORM. You must also unlock your keyboard.
Sending the escape sequence
ESC-b unlocks the keyboard programmatically, or depressing
the
RESET key once also unlocks the keyboard.
VTURNON reconfigures the terminal and the driver without performing the following
operations, which are usually carried out by VOPENTERM.
• Initialize local form storage
• Clear screen
• Enable the
USERKEYS function keys
• Disable or enable the USER/SYSTEM key as specified in the SHOWCONTROL word
Unlike VOPENTERM, VTURNON will not ask you to press the BLOCK MODE key if you are using
an HP2640B or HP2644 terminal and the terminal is not on block mode.
Example
The following examples illustrate a call to VTURNON: