Function block prog. in Pascal

[mumarzia]

Dear Fellows,
Can any body let me know the web address or other stuff from where I can learn programming the function blocks in pascal for S7.

I have a problem in understanding a command

temp:=DWORD_TO_REAL(db20.dbd0)

how it works.

Bye,
Umar Zia

 

[dchartier]

Hello, mumarzia;
I only saw your post today, ans I hoope this answer will still be usefull.

Siemens' Pascal-like language is called SCL, and you can find the SCL programming manual at this address:

http://www4.ad.siemens.de/-snm-0135...i.dll?func=cslib.csinfo&lang=en&objid=5581793

The instruiction you are looking at is a Typecast function; the value in DB20.DBD0 is a DWORD format, which you convert to a REAL (IEEE floating-point value) before loading it to the variable "temp" (which presumably has been declared as a REAL value).

Hope this helps,
Daniel Chartier