Rockwell Automation 2706-LSW DL40 PLUS OFFLINE PROG.SFTWR.USER MANUAL - Manual (Page 129)

ASCII Character Sets C–2
Publication 2706-6.2
Extended ASCII Character Set
To enter an extended ASCII character, use the [ALT] key in combination
with the numeric keypad section on your keyboard. Hold down the
[ALT] key, then enter one of the decimal values found in the extended
ASCII character chart below. The selected character will appear in the
offline message window when you release the [ALT] key. Extended
ASCII characters are not available with the onboard editor.