The IEC61850 MMS server technical key setting corresponds to the IEC61850 IED name. This name is used to identify the device via a IEC61850 MMS client. The size is restricted to 32 characters. According to IEC61850-7-2 Ed. the TechnicalKey represents an IEC61850 VisibleString. Thus the following characters are allowed: VisibleString ( FROM ('A'|'a'|'B'|'b'|'C'|'c'|'D'|'d'|'E'|'e'|'F'|'f'| 'G'|'g'|'H'|'h'|'I'|'i'|'J'|'j'|'K'|'k'|'L'|'l'| 'M'|'m'|'N'|'n'|'O'|'o'|'P'|'p'|'Q'|'q'|'R'|'r'| 'S'|'s'|'T'|'t'|'U'|'u'|'V'|'v'|'W'|'w'|'X'|'x'| 'Y'|'y'|'Z'|'z'|'_'|'0'|'1'|'2'|'3'|'4'|'5'|'6'| '7'|'8'|'9') )