Alarming using Symbolic Tags (TIA Portal / WinCC)

Hello,

With the S7-300/400, alarming in the HMI is done using absolute addressing, overlaying HMI tags of type "Word" over bits used in data blocks and using individual bits of each tag as alarm trigger bits in the HMI.

With the S7-1200 and optimized data blocks, the absolute addresses are not available. As I understand it, optimized means that stored bits in data blocks etc. are automatically packed together to save memory. So if I have an "optimized" data block full of fault bits, what is the best way to get them into the HMI as words to use as alarm trigger bits?

It seems there are 2 possibilities I've come across:
1) use the bit to word conversion FC available on the siemens website, which seems a bit ridiculous for large numbers of alarms.
2) Use non-optimized data blocks for faults.

Anyone have a better solution?

Thanks!

Bumping this because I am currently looking for a solution to this.

BUMP! I too am looking for a "best practice" on this.

For now, i'm doing exactly what we always did in step7: our alarm DBs have 16 boolean STRUCTS (so we can create comments on each bit), the DB is created non-optimized and a nabsolute address is used in WinCC tags to access each STRUCT as a WORD...

This is so old and counter-intuitive, can't believe there's still no better option in an TOTALLY INTEGRATED way.....

The way I've been doing it since my original post is to continue using words to store the alarms and for sending alarm data to the HMI, but in the program just use the Word.bit. So if I want to set bit 1 of a specific word under certain conditions, in the program I set AlarmWord1.x1. This allows the use of optimized data blocks, but still doesn't solve the problem that you can't really give the alarm bits descriptive names, at least as far as I know. I guess the only way to do that would be to make extra bits with symbolic names and link those to AlarmWord1.x0, AlarmWord1.x1, etc. Which is still a bit clunky.

Then again, not really TOTALLY INTEGRATED eh?

You should be able to set directly the HMI's bits in the logic. THAT would be able to be called integrated...

IF I0.0 THEN SET HMI.DisplayAlarmPowerIsOff

Click to expand...

Not sure if this is what you're referring to, but in TIA V12 & V13 (and I think V11), you can create a word in a program data block, then when you assign specific bits in that word to alarms, buttons, etc. the "word" tag automatically becomes an HMI tag as well. You don't have to create HMI tags separately.

Nope, that's actually the same functionality we had on previous software (wincc flex n stuff)...

Thing is, you've got a supposedly TOTALLY INTEGRATED environment, still you have to do lots of things:

1: create DB or declare @ symbol table WORDS
2: program/set bits of the WORDS on alarm conditions
3: configure alarm WORDS to alarm groups
4: give text to configured alarm word's bits
5: make sure you have swapped word bytes otherwise you won't link the right bits

Even after doing all that, you still end up with UNCOMMENTED alarm WORD BITs. You've got to know exactly what you are doing in order to follow the bits to the right messages (this is definitely not intended for newbies)

Question is: Why all that complexity for the most basic functionality?

Best way I have found is to use M memory - you can declare the words for HMI alarm tags and also add symbols to the individual bits in those words for the PLC code.

jb2020 said:

Best way I have found is to use M memory - you can declare the words for HMI alarm tags and also add symbols to the individual bits in those words for the PLC code.

Click to expand...

That does work. I use the slice based addressing to get bits out of a word.

https://support.industry.siemens.co...word-by-word-and-symbolically-?dti=0&lc=en-WW