Rockwell Automation 2706-LV2P_LV2R_LV4P_LV4R DL40 PLUS USER MANUAL - Manual (Page 168)

ASCII Character Sets D–2
Publication 2706-807
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.