Automatic control function programming manual ladder language

Programming error causing a CPU fault
Access to a prohibited address:
- &format parameter error,
- end of string outside authorised area.
8.2.6 Open a Keyboard Acquisition scano
Syntax
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scano(&question, width)
&question: Address of a character string (ending with a ZERO byte).
width:
Opens a keyboard acquisition.
Maximum width of the entry field.
Operation
The system displays the string pointed to by &question at the bottom of the screen and opens the dialogue after the
string.
If parameter &question == 0, no string is displayed.
Character entry is controlled by the system line editor.
The line editor checks that the number of characters entered is less than «width».
The line editor commands are the conventional commands of the part programme editor:
- cursor movement left and right, start and end of line,
- character insertion and deletion,
- entry is ended by the line feed key.
! CAUTION
The putchar() and printf() display functions are prohibited during a keyboard acquisition.
Return code
If OK
0
Error
-1: Not in transparent mode, the calling task is not a %TF task.
-2: Resource already in use (a keyboard acquisition is already in progress).
Programming error causing a CPU fault
Access to a prohibited address:
- &question parameter error,
- end of string outside authorised area.