Siemens SINUMERIK 840Di Function Manual page 1055

2.12.5 FB 5: GETGUD read GUD variable
Description of functions
The PLC user program can read a GUD variable (GUD = Global User Data) from the NCK or
channel area using the FB GETGUD. Capital letters must be used for the names of GUD
variables. Every FB 5 call must be assigned a separate instance DB from the user area.
(multiinstance capability in SW 3.7 and higher). A job is started when FB 5 is called by
means of a positive edge change at control input "Req". This job includes the name of the
GUD variable to be read in parameter "Addr" with data type "STRING". The pointer to the
name of the GUD variables is assigned symbolically to the "Addr" parameter with
<DataBlockName>.<VariableName>. Additional information about this variable is specified in
parameters "Area", "Unit", "Index1" and "Index2" (see table of block parameters).
When parameter "CnvtToken" is activated, a variable pointer (token) can be generated for
this GUD variable as an option. This pointer is generated via the VAR selector for system
variables of the NC. Only this method of generating pointers is available for GUD variables.
Once a pointer has been generated for the GUD variable, then it is possible to read and write
via FB 2 and FB 3 (GET, PUT) with reference to the pointer. This is the only method by
which GUD variables can be read. When FB 2 or FB 3 is parameterized, only parameter
Addr1 ... Addr8 need to be parameterized for the variable pointer. GUD variable fields are an
exception. In these, Line1 .. Line8 must also be parameterized with the field index of this
variable.
Successful completion of the read process is indicated by a logic "1" in status parameter
Done.
The read process extends over several PLC cycles generally 1 to 2).
The block can be called up in cyclic mode only.
Any errors are indicated by Error and State.
Power Line Basic PLC Program (P3)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
Error := M1.0,
Done := M1.1,
State := MW2);
2.12 Block descriptions
//Addr1:=STR.Path
_WST,
//Addr2:=STR.PNam
e_WST,
//Workpiece-
program selection
Detailed description
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