I do not understand how bit selection works. Tia Portal v15.1, WinCC Professional.

Here is an example from the Tia Portal documentation:

In the text list element, I specified the text for bits 3, 4, 6.
In runtime, I set bits 2, 4, 5.

I expect the text to be displayed for bit 4, because:
- it is configured
- Of all configured bits, only it is set.

But no text is displayed. The text is displayed only if one of the bits 0..7 is set.

I want the text to be selected only from those bits that are specified in the text list, no matter what state of the remaining bits. Is it possible?

I added some screenshots in the attachment.

Thank.

Hello Konstantin_D,

that is strange, I would also understand the bit selection like you described.

One thing I would do just for testing, is to only set one bit at a time and then check the output.
After that, set two bits at a time... and so on.
Maybe that helps to find out, how it really works :/

Greetings,

Nzett11

Hello Konstantin,

did you activate "Bit selection for text and graphic list" in [Runtime settings > Screens > Bit selection]?

Regards,

Frink

Hi Konstantin,

Konstantin_D

No

But, I guess, you should. See TIA help > Notes for bit number text list. From my understanding it then (when more than one bit is set) shows the text which is configured for the set bit with the least significance.

Regards,

Frink 

Hello Konstantin, 

Konstantin_D

[...]

Why am I interested? If WinCC checks only the configured bits, then I can transmit the states of different equipment in one double word. If WinCC checks all 32 bits, then each equipment needs its own tag.

good intention. But I guess it will not work this way, because there is no configuration for the screen object to decide whether bits 0-3 should be used for the one screen object and bits 4-8 for another one.

Maybe a bit more complex for engineering would be to use the integer value of the tag. E.g. integer values 0-7 instead of bits 0-3, integer values 8-15 instead of bits 4-7, ...

Regards,

Frink

Did you solve this issue?

Seeking same answer.

Please share if you have solution.

Thanks.