Button pressed on HMI does not change the corresponding plc tag value

Hello, Everyone,

I have a question to ask. In my project, I use a 'Calculate' Button on the HMI screen to activate/deactivate a NO contact in my plc program. So I add a click event 'invertBit' to the 'Calculate' Button, and the tag was linked to the plc tag 'calculate'. But it was not working. I couldn't find out the problem. Can someone give me some suggestions?

BTW, there was another question, modify value in watch table was not working, I tried to modify the plc tag value 'calculate' from false to true, but after I entered 'true' in the modify value box and pressed the modify icon, nothing was changed. Anyone have an idea about this?

Attached is the screenshot of the reference button property.

Thanks.

Hi, William,

Attached is the screenshot of my plc tag definition.

Thank you.

Hi, William, now problem solved. There was a overlapping of the memory, I have another int tag at MD18. I have changed it to another address, and now it works.

Thank you. 

Have a nice day. 

William_B

kevinlin_5

Attached is the screenshot of my plc tag definition.

Please make 100% sure that M18.0 is not overlapping with any other memory area like MB18, MD18, MW18, MW17, .....

Next - please show us where/how the M18.0 is used in the code.
(for example: as-is or through in-out parameter)

Then - how are you testing? Via simulation or by actual hardware? In other words how do you know you are not getting the right results?

Hi, William,

Now I have the same problem again. My button pressed in the HMI panel did not do anything, which was supposed to set a bit value. This time my memory used are from I1.0 to I4.6, ID5 to ID17, Q0.0 to Q9.0, QD10, M100.0 to M104.3, and M200.0 to M201.3. Is there any memory conflict in my memory setting?

Thanks.

Hello kevinlin_5,

to check for problems with overlapping addresses do these steps:

• Right-click on your PLC.
• Select "Assignment list" in the context menu.
• Check for overlap.

If there isn't any overlap then at least you know that it's not the reason this time.

kevinlin_5

Hi, William,

Now I have the same problem again. My button pressed in the HMI panel did not do anything, which was supposed to set a bit value. This time my memory used are from I1.0 to I4.6, ID5 to ID17, Q0.0 to Q9.0, QD10, M100.0 to M104.3, and M200.0 to M201.3. Is there any memory conflict in my memory setting?

Thanks.

You do not give us much to work with.

Using INPUTS and OUTPUTS as HMI buttons are never a good idea. Do remember that (especially) the inputs are meant to change every PLC cycle. These are changed by physical devices connected on the input pins of the PLC or by communication.

Review your PLC code. Are any of the memory areas you mentioned written to by PLC code? Depending on how the memory is changed, this will also effect your HMI.

Helpful?
w

 Dear H.J.

Thank you for the suggestion. It's really helpful to me.

H.J.

Hello kevinlin_5,

to check for problems with overlapping addresses do these steps:

• Right-click on your PLC.
• Select "Assignment list" in the context menu.
• Check for overlap.

If there isn't any overlap then at least you know that it's not the reason this time.