ST Help with String INSERT

[_Dock_]

I'm new to ST so go easy.

Studio 5000
L33ER PLC

I'm trying to take 2 strings, merge them into 1 string. with a space between the 2 strings.

this works in ladder just fine.

However this code in ST does not work.

if
ST_RUN
then;

DTOS(Material_ID[1],Material_IDString[1]);
INSERT(Material_IDString[1],space,3,MatIDPlus[1]);
CONCAT(MatIDPlus[1],Material_Description[1],HMI_Mat_List_Display[1]);
CONCAT(MatIDHMI,HMI_Mat_List_Display[1],CI_MaterialStrings[1]);

If I change the Material_ID, the DTOS works
Material_IDString is valid and correct
The INSERT instruction with the Space is the problem, after the Space, the MatIDPlus remains the same of the old Material_IDString

The space String tag is " ", the insert function writes the " " to start at bit 3.

 

[_Dock_]

Well here you go, the second you reach out for help you figrue it out.

MaterialID, was 2 digits, I had the space written to bit 4 instead of bit 3.

It works now...

Its late and im tired!

 

[_Dock_]

I guess ill add that I still don't understand why the the MatIDPlus wouldnt get the correct value.

You would think it would read "MatID # 40D escrtiption"

All the while still updating the material ID number regardless of where the space is. I guess because there was a valid character in its place?

 

[drbitboy]

You would think it would read "MatID # 40D escrtiption"

Actually, I would not think that, because at the time of the INSERT call, the source string argument (e.g. Source A here) is "40" and the string "Description" has not been concatenated yet.

Also at that link, it notes that the position argument, Start, should be between 1 and the DATA size of the source, the latter is 2 in this case. Later it states that a fault should be thrown if Start is greater than the DATA size. Apparently those are typos in that Rockwell manual, as it works with DATA size + 1.

Finally, inserting a space at (i.e. after) the end of a string (Start = 3 = 2 + 1 for the 2-character Source A string "40") should be the same as concatenating a space to a string, so using CONCAT would make the code robust to input strings of lengths other than 2 e.g.

• "0"
• "9"
• "140"
• "-40"
• etc.