Siemens SINUMERIK 840D sl Function Manual page 1052

Detailed description
2.7 Structure and functions of the basic program
Symbolic accesses
An entry is made in the symbol table to allow data access in symbolic form:
Symbol
UData
Access operations in user program (list includes only symbolic read access):
...
...
68
Operand
DB 20
L "UData".UDInt[0];
L "UData".UDInt[1];
L "UData".UDInt[2];
L "UData".UDInt[3];
U "UData".UDHex0[0];
U "UData".UDHex0[1];
U "UData".UDHex0[2];
U "UData".UDHex0[3];
U "UData".UDHex0[4];
U "UData".UDHex0[5];
U "UData".UDHex0[6];
U "UData".UDHex0[7];
... ...
U "UData".UDHex0[15];
L "UData".UDReal[0];
Basic logic functions: PLC Basic program powerline (P3 pl)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Data type
UDT 20