[Studio5000] Insert a char before every occurence of space chars from a string

[Nico38]

Hello guys,

I am working with a CompactLogix, which communicates over Ethernet/IP with a pin marker.
Basically, The PLC sends the texts to be marked to the marking UC, and then it triggers the marking.

The marking UC doesn't accept space characters into the texts string to be marked. To get rid of this situation, every space characters must be escaped with '\' character.

Example :
Text to mark : 'This is the content to print'
String to send to marking UC : 'This\ is\ the\ content\ to\ print'

What would be the cleanest way to achieve such a goal ?
Could you give me some tips, to help me start with that task, because I am not an expert with Allen-Bradley PLC programming.

Thanks in advance for your help

 

[Level]

Hey Nico38,

Welcome to the forum!

Do you always send the same content?
Does the size of string to print vary? Do the # of words vary as well?

I'd likely use a "FIND" and "INSERT" instruction set.
Look for the first space character using the "FIND" - you should return the position of the space in the string.
Check for the next by starting at the located character +1.

Use the insert instruction by taking the RESULT from the FIND and dropping in your "" character.

Likely need a bit of finessing, but would get the job done.
Good luck!

 

[drbitboy]

...use a "FIND" and "INSERT" instruction set. ...

MOV 1 inext  OTE index.0



LBL loop  XIC Do_escape   LEQ inext thestring.LEN    FIND String_tag Space inext inext    GRT inext 0   INSERT String_tag Backslash inext String_tag   ADD inext 2 inext   JMP loop



OTU Do_escape

​

• String_tag is the STRING tag to be modified
• Space is a STRING tag of .LENgth 1 containing a space character (ASCII 32; $20)
• Backslash is a STRING of .LENgth 1 containing a backslash character (ASCII 92; $5C)
• Do_escape is a one-shot BOOLEAN tag that is OTLed to 1 whenever a new string arrives in String_tag, and has not yet had its spaces escaped

Caveats

• There are multiple ways, other than OTL/OTU and Do_escape, to ensure the spaces are not repeatedly escaped, once per scan.
• The should probably be some logic to protect against the string becoming too long (82 chars, typically?).

 

[MikeyN]

Something that we have done, is to create a string array (in this case named StringArray datatype STRING[7]) to build our final data. You can fill the array with all of your variables, and any constants needed. For example:

StringArray[0] = "This"
StringArray[1] = "is"
StringArray[2] = "the"
StringArray[3] = "content"
StringArray[4] = "to"
StringArray[5] = "print"
StringArray[6] = "/ "

Then we use a series of CONCAT instructions to fill a second string tag (In this case named FinalString datatype STRING) to build the part number, or data to send off wherever it needs to go.

CONCAT FinalString StringArray[0] FinalString CONCAT FinalString StringArray[6] FinalString CONCAT FinalString StringArray[1] FinalString CONCAT FinalString StringArray[6] FinalString CONCAT FinalString StringArray[2] FinalString CONCAT FinalString StringArray[6] FinalString CONCAT FinalString StringArray[3] FinalString CONCAT FinalString StringArray[6] FinalString CONCAT FinalString StringArray[4] FinalString CONCAT FinalString StringArray[6] FinalString CONCAT FinalString StringArray[5] FinalString

You can see in the image attached that FinalString contains "This/ is/ the/ content/ to/ print" (well, at least "This/ is/ the/ conte", but hopefully you get the idea). You are able to change any of the StringArray variables as you see fit before turning on the XIC BuildData to concatenate the final string. It isn't the prettiest to look at, especially for really long final strings, but I think it is easier to understand. Hope this helps some.

 

[Nico38]

Thank you guys for you fast and valuables replies !

Because the source string may have different numbers of characters, I've chosen the solution using a Loop with FIND and INSERT, and it works just as expected.

 

[JBooth]

I have seen this done using FSC instructions as well. But i think a couple of the other methods mentioned previously are what i would end up using.

 

[drbitboy]

Thank you guys for you fast and valuables replies !

Because the source string may have different numbers of characters, I've chosen the solution using a Loop with FIND and INSERT, and it works just as expected.

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