P3: Basic PLC Program for SINUMERIK 840D sl
13.8 Structure and functions of the basic program
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
893
Although only a REAL value is used initially in the example, a field (with one element) has been created for the
variable. This ensures that extensions can be made easily in the future without the symbolic address being
modified.
Symbolic accesses
An entry is made in the symbol table to allow data access in symbolic form:
Access operations in user program (list includes only symbolic read access):
Note
ARRAY OF BOOL are always sent to even-numbered addresses. For this reason, an array
range of 0 to 15 must generally be selected in the UDT definition or all Boolean variables
specified individually.
Symbol
Operand
Data type
UData
DB 20
UDT 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];
...