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MS_107962653-Newcomer
3-Newcomer
July 10, 2024
Solved

REAL variable from Siemens PLC is showing the wrong value in Kepware

  • July 10, 2024
  • 1 reply
  • 2864 views

Hi Experts,

I'm a beginner with Kepware and i've now encountered an issue i would really appreciate some help with solving: 

In my Siemens PLC i got an REAL variable that has the value "25.999".
When i added the tag to Kepware (Float) and launched quick client the value is now shown as 1.10415E+09.

How do i get Kepware to show the actual/same value as i can see in the PLC?

 

Thanks in advance!

 

Best answer by ntripathi

Greetings @MS_10796265 

 

To configure the byte order for a Siemens PLC connected to KEPServerEX via OPC UA, kindly follow below steps:-

 

Open KEPServerEX Configuration --> Device Properties --> Addressing Options --> Byte Order.

 

ntripathi_0-1723466521135.png

 

For more detailed guidance, you might find the OPC UA Configuration Manager Manual.

1 reply

N
ntripathi15-Moonstone
15-Moonstone
July 17, 2024

Greetings@MS_10796265,

 

I hope you’re doing well.

It seems you’re experiencing a common issue where the value displayed in The KEPServerEX does not match the actual value from Siemens PLC. This discrepancy often occurs due to the way floating-point numbers are handled between different systems.

Here’s a step-by-step guide to help you resolve this issue:-

 

Check Data Type Compatibility: Ensure that the data type defined in KEPServerEX matches the data type of the variable in the PLC. Siemens PLC uses REAL for 32-bit floating-point numbers and LREAL for 64-bit floating-point numbers.

 

Verify Tag Configuration: In Kepware, double-check the tag configuration for the REAL variable. Make sure that the correct address and data type (Float) are selected.

 

Byte Order: The issue might be related to the byte order of the data. Siemens PLCs and KEPServerEX might use different byte orders, which can cause the value to be interpreted incorrectly. You may need to adjust the byte order in Kepware’s settings to match that of the PLC.

 

I hope this helps you resolve the value discrepancy and get the correct readings in Kepware. If you need further assistance, please let us know.

M
MS_107962653-NewcomerAuthor
3-Newcomer
August 12, 2024

Hi @ntripathi,

 

Thank you for your response.

I've verified data type compability and tag configuration, it's correct.

But im clueless on how/where i configure the byte order? 

 

I forgot to mention in my original post that the connection between the Siemens PLC and Kepware is via OPC UA.

 

Best Regards

MS

N
ntripathi15-MoonstoneAnswer
15-Moonstone
August 12, 2024

Greetings @MS_10796265 

 

To configure the byte order for a Siemens PLC connected to KEPServerEX via OPC UA, kindly follow below steps:-

 

Open KEPServerEX Configuration --> Device Properties --> Addressing Options --> Byte Order.

 

ntripathi_0-1723466521135.png

 

For more detailed guidance, you might find the OPC UA Configuration Manager Manual.

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