Siemens SINUMERIK 808D ADVANCED Commissioning Manual page 314

Tag identifier
OP
314
Meaning
The tag executes the specified operations.
The operations listed in Section "Operators (Page 324)" can be executed.
For the purpose of accessing the NC, PLC, and drive data, the complete variable name
should be placed in quotation marks. Section "Addressing components (Page 352) " de-
scribes how addresses are formed.
PLC: "PLC/MB170"
NC: "NC/Channel/..."
Example:
<LET name = "tmpVar" type="INT"> </LET>
<OP> tmpVar = "plc/mb170" </OP>
<OP> tmpVar = tmpVar *2 </OP>
<OP> "plc/mb170" = tmpVar </OP>
More than one equation can be used within an operation tag. A semicolon marks the end
of the instruction.
Example:
<op>
x = x+1;
y = y+1;
</op>
Character string processing:
The operation instruction is able to process character strings and assign the results to the
string variable specified in the equation.
The identifier _T should be placed at the start as a means of identifying text terms. For-
matting of variable values is also possible. The identifier _F should be placed at the start
of the formatting regulation, followed by the format instruction. The address is then speci-
fied for the variable.
Example:
<LET name="buffer" type="string"></LET>
...
...
...
<OP> buffer = _T"unformatted value R0= " +
"nck/Channel/Parameter/R[0]" + _T" and " + _T"$$85051" + _T" for-
matted value R1 " + _F%9.3f"nck/Channel/Parameter/R[1]" </OP>
Commissioning Manual
01/2017