Transfer float out of words

 Hi -dFx-!

-dFx-

 your answer would be best if it wasn't about modbus (large array).

To proceed with AT keyword, you have to copy array elements you wish into temporary to then cast them to real datatype. And each of those datas have to be defined in DB.

 IC, yes, it would lose a bit of it's usefulness with such a big ammounts of data.

... unless you only define it once and then reuse the ONE defined Real value by sth. like:

for #i := 0 to 99 DO

    #float_word[0]:=#word_2;

    #float_word[1]:=#word_3;

    #float_array[#i] := #float;

end_for;

that could work better I guess (at least as the massive ammount of set Reals in my previous suggestion)

Doing a function block on your principle could be fine.

Then just loop call it with each parameters and copy each output.

-dFx-

Siemens have swap (Correct name is endianness of system), and it may concern :

 - Bytes in your word

 - Word in your real

If your value doesn't match sent value, then consider testing each possibilities.

Don't forget that we all supposed that your datatype would be IEEE float. But by the past I've faced some modbus float that were Integer part in first word and decimal part in second word.

EDIT: added endianness

EDIT2: without typo

I just want to be prepare if its going to be a problem.

1.
If the byte is swapped when it comes to bit. I see what I need todo, if we talking about bit 0, then it will be bit 8 instead of bit 0.

2.
What about the to words => float, what is the best way to swap the words here?
If bender has not swapped the word like Siemens has.

To do byte swapping, you may use in bitshift instruction category, rotation of 8 (either left or right) on each word.

To do word swaping, just pass word1 instead of word2 to your words_to_real function.

If using MOVE_BLK_VARIANT you may need a copy your 2 words into a new array arranging them in new order (word2 in place 1).

huggy_d1

My apologies to any Endian's offended by the use of Good and Bad to describe them.

Those entangled with Endian-ess should stand up and be noticed:
(Step7 V15, S7-1200 FW4.2)

Thank you all :)

Now shall I be prepared for what comes up during testing :)

I have problem using the move block function. It give me a error...
It should be reconfigured like you said?
Please see attached picture:

Hello.

AutoGen_7361160

I have problem using the move block function. It give me a error...
Please see attached picture:

Error: 16#‭8281‬ => "The COUNT parameter has an invalid value"

That instruction is made for moving data from one structure to another same type structure. In your case you are pushing 2 WORDS into 1 REAL.

Have a look at the notes by NiM_0021 at timestamp 3/20/2018 1:15 PM.

BR

Add video clip to show in general how to define an AT overlay.