Move string variable

huggy_d1

In Step 7, strings are represented by a bunch of bytes with a structure like this:

max length [default for :string = 254]
length [actual number of characters in string, like 'here' = 4]
array of char holding the values.

For the 'here' as a string[254]:
byte 0 = 254
byte 1 = 4
byte 2..5 = 'here'
bytes6..254 = not observed

You will want to use absolute addressing for your string. Let's assume your string tag the first tag in your DB:

DB1.DBB0 = 254
DB1.DBB1 = 4
Then push your block move to P#DB1.DBX2.0

There are probably better ways, but this explains what happens in the background.

I think many would run the character array into an FB, then use the AT overlay to help create the string more easily.

 Dear huggy_d1,

I have a problem about move string variable, in this my program, i use MB address for data of Coil ID. Now i want to move variable from this MB to other MB, but i don't know how to move it.

I use the SFC20 in the Simatic Manager but it's not ok.

Can you help me to fix this problem?

Thanks!

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Split from Block Move from Array of byte to String.

Hello,

Have you tried to use functions from the IEC Function Blocks library? For example FC31 REPLACE ?

New question published by AutoGen_6455290 is split to a separate thread with the subject Transfer a String data to a String address.

Best regards
Jen_Moderator