S71200 Tag values off

Hi there,

I am connecting an S71200 to ignition and have had no issues getting it connected with the driver and getting the tags communicating - no issue. The issue is with some of the database tags (I have data blocks un optimized). They are showing up as values way off from what they should be. I am not sure if this is a scaling issue or some other issue I am missing. For example the highlighted IO1 tag below should be a 1. Thanks in advance for any support.


Can you show your tag address and the datablock? This looks like a datatype adressing issue.

Hi Chi,

Yes of course, please see below, let me know if this is enough detail.

See designer Tag Data

See TIA Portal Data Block information: (as well the modbus sim being used to generate the input of 1)

You’re reading too much data by using D42 instead of W42 in the address.

Thank you Kevin!

Sure, @chi did the heavy lifting by asking the right question, he just wasn’t in the right timezone to finish it :wink:

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Is there is an easy way to determine from the siemens datablock address how to properly reflect within the tag selection within Ignition? I have a similar issue with an analog value (seen above at DB1.DBD112) which does not show correctly either. I can open a new topic as well if easier - also understanding this may be a lack of PLC addressing knowledge on my part :slight_smile: :grinning:

Have you looked at the Address Syntax section in the docs for the Ignition Siemens driver?


Hi Kevin,

Yes you bet, that is why I wonder if it may be a lack of knowledge on the PLC addressing side. I did get it to work as FLOAT as the data type, and REAL as the address path in the DB, but when the value changes it does go wayy off again. After some digging realize I had been messing with the scale factor and that I never set it back. Thanks again for your support.