S7 / Step 7 converts data formats ?

I came across this:

http://automationsoft.blogspot.com/2008/05/tip2-pid-function-documentation.html#

which shows this code (Network #2 & 3) :

http://lh4.ggpht.com/nawaphun/SC-2NrtiMfI/AAAAAAAAARU/MpjaWZJf5AM/clip_image0193.jpg

which implies to me that I can use a MOVE box, put in a Real and get out a T# ?



Have I been wasting code / time in explicitly using ROUND and other functions to convert types when all I needed to do is MOVE them ? Was the person that taught me S7 wrong ?

Move does not convert the data type, it simply takes the binary bit pattern stored in one variable and moves it to another.

Highlight the move box and hit F1 to get the Siemens help

As i see it and it just moves a value into somewhere when you start a plc(0B100) but doesn't convert it
If i remember well OB100 is some ob that you use to set values/bits correct when you start a plc so everything would be correct to start a program it is more like initializing
But no converting is been done

The links are no good, so we can't (I can't) see what it is that you mean, but to use MOVE of a REAL to a T# is possible - no conversion is done - as has already been mentioned.
But thinking about it, it is indeed not logical to do so, because the bit pattern that corresponds to a certain REAL value, is gibberish when interpreted as a T# value.
So, it is the symbolic assignment of the addresses that is wrong: The addresses are not really REALs or T#'s.
That, or it is a programming error: Somebody forgot the line RND in
L realvalue
RND
T doublevalue.

A long shot: maybe the MOVE is part of some kind of random value generator.

theDave2 said:

I came across this:

http://automationsoft.blogspot.com/2008/05/tip2-pid-function-documentation.html#

which shows this code (Network #2 & 3) :

http://lh4.ggpht.com/nawaphun/SC-2NrtiMfI/AAAAAAAAARU/MpjaWZJf5AM/clip_image0193.jpg

which implies to me that I can use a MOVE box, put in a Real and get out a T# ?



Have I been wasting code / time in explicitly using ROUND and other functions to convert types when all I needed to do is MOVE them ? Was the person that taught me S7 wrong ?

Click to expand...

The first link is good, the second gives me 404 error.

Looking at the first link I found a piccie that shows network 1, 2 and 3 and they show MOVE instructions. Going to assume thats what you are referring to.

Look closer at the declaration table just below that one. pidDB.gain, pidDB.rate and pidDB.reset are all REALs. So they are moving reals to reals.

Nowhere in that article did I find any such thing that refers to moving Reals to T#......

I think the OP is pointing out that, if he wanted to, he could move a real variable into a time variable.