Writing Chars to USB - Why it is so unstable?

Hi All

I’ve got a problem while saving some data to the USB Stick.

On the CPU site I have a DB with 40 Chars. I am detecting when the new entry appears and then I am writing it immediately to the USB.

On the HMI site I’ve created 40 SmartTags and linked them to the CPU. If I am writing down directly the smart Tags by means of ‘Lineprint’ command then it is working fine (I’ve managed to write down 20.000 entries without losing single one). But in my CSV file it comes as decimal coded. (Ex. Instead of ‘W’ I get ‘87’). I did tried to use instead of

Lineprint  SmartTags("Var_01")                           - working fine

Lineprint ChrW(SmartTags("Var_01"))                - very unstable

but this is not stable at all. I mean sometimes I can write down 1000 Entries but some time the entree is not in ONE line but is split into several lines…. Please see the example below:

Does anybody can explain why it happens so? And of course how can I solve this problem!

Thank you!!

Hello,

what datatype are your SmartTags?

I understand you want to write them into the CSV file, but NOT decimal coded.

You use ChrW() to change from decimal to the coded character.

I looked it up and found the following. Maybe this interrupts your lines, if the values are too low?

https://msdn.microsoft.com/en-us/en-en/library/613dxh46(v=vs.90).aspx

ChrW takes CharCode as a Unicode code point. The range is independent of the culture and code page settings for the current thread. Values from -32768 through -1 are treated the same as values in the range +32768 through +65535.

Numbers from 0 through 31 are the same as standard nonprintable ASCII codes. For example, Chr(10) returns a line feed character.

 Do you get the same problem if you use Chr() instead? How big is the valid range you need?

Hi H.J.

yes you understood me correctly - it should NOT be decimal coded.

I have tried Chr, Chrw, Asc, AscB, AscW.... it seems to be the same problem for all those options....

Since the system is not build yet I am simulation this data. I am simply using a counter to count between 65 and 90 (from A to Z). So the smallest value is 65 dec.

The only solution for now I see in conversion from dec to ascii in Excel, but..... Before I do that I want to be sure there is no better way.

Well, any other suggestions?

Thanks....

Hi,

my idea would be to convert integer>char in the PLC before sending the data to the HMI - it's better equipped for processing data.

A useful command in SCL could be INT_TO_CHAR, and here is an interesting forum post about the conversion in AWL: https://support.industry.siemens.com/tf/ww/en/posts/62618/.

Hope it helps.

Hi,

well it is already done....

on the PLC site I have got a DB with Array(1..40) of Char.

Thanks

Hi,

I hope you undrestood my previous post.... I have had it in my DB as char already...

Have you got for my any other suggestions?

Greetings.

Tym

Hi Tym,

yeah, sorry. Missed that part in your original post. At the moment I don't have an idea, but if I think of something I'll let you know.
Maybe someone else wants to share some suggestions?