Hello,

I have a function that writes a double value to a tag on the PLC. The block is made in SCL, but which datatype do I have to use in SCL to be able to get the double value?

As I recall, double value is a 64 floating point, where float is a 32 floating point. In the library, there is a function to convert 32 bit to 64 bit where the datatype of a 64 bit is a struct with two DWORDS in it. 

How can I assign the double value to the datatype in SCL? 

Hello jacek,

Thx for the answer..

I have a function which will search ua for a specific ID and returns all field values of type int,double,float etc. The field values are then sent to the PLC for further use. Which datatype do I have to use then in SCL to assign a double value?

I'm working with PCS7 and in the Siemens APL library there is a block which will convert real64 to real. The real64 of that block consists of a struct with:

Top4bytes :DWORD

Bottom4bytes :DWORD

Hello,

Can somebody anwer me how to proceed? 

Thank you!

Hello,

you have already answer. Simply is not to clear to me. What you want to do in your PLC if you don't have that <data type> support on your HW? In other case you can calculate internally for yourself 2 DWORDs separately and then assign your calculation from one DWORD to another as is required. Example:

<destin. DWORD upper>:=<your upper calculation DWORD>;

<destin. DWORD lower>:=<your lower calculation DWORD>;

Helpful?