Flexy 205 reading boolean in Integer value

I have an application with Flexy 205 communicating in Modbus TCP with PM573 ABB controller. I tested successfully a float tag using, for example, address 40097F to read %MW0.97 value on controller.

I tested too a boolean tag using, for example, address 40029#0 to read %MX0.29.0 value on controller, but without success. PM573 controller uses byte structure for boolean tags, for example, %MX0.29.0 … %MX0.29.7, and I understood that Flexy 205 uses Integer (16 bits) values in the minimum size. I tried different ways to read the value, for example, using directly address 29, and without success too.

In the same time, I configured a SMS Alarm for this tag and I received the messages when change the value from 0 to 1, even Flexy 205 doesn´t change the value on “Value” configuration screen (in View mode).

Am I using wrong way to define the address? Is there anything else that I can do?



did you already make changes in this section?

Hello Tim.

No, I don´t. What can I do in this section? I´m asking because the Modbus TCP Port is correct in my application, I believe. I can communicate with a float value.

Please, let me know how I can use this section to resolve.

Wait are you saying that there’s no error symbol when you’re looking at values in this section?

Yes, without errors. Please, see below the images (tag name: Status).

Can I jump on and take a look at this setup on teamviewer?

Hello @derekstesse,

Tim is out on vacation this week and I was reviewing this issue. It looks like he helped you over teamviewer last. Are you still running into any issues with the modbus communication?


Hi Derek,

Could you please tell me what was the error? I´m having the same issue.

Hi, I am having the same issue.
May I know if there is a solution to this?
How do you read a boolean from a Modbus address?
Was what you did correct? E.g. putting 40029#0 to read the first bit of the word?