Creating alarms in S7 300/400

Hello Gentelmans,
I'd like to ask about creating alarms in S7 300/400.
Do you usually create UDT-alarms and UDT-notices with all alarms and notices inside (I'am thinking about small application - let's say about 50 alarms) and later trigger it in FBalarms where you describe all conditions? How do you usually do this?

I would normally use the HMI/Scada Alarm system to handle the alarm visualization.

Thanks a lot RheinhardtP for your reply,
but I think I didn't expain what I mean very well..
On the HMI side permited type is INTEGER.
For ex. if I have 10 alarms, I'll need only one integer, so I'll make a DB with one integer, end in FB will trigger each byte responsable for each action.
And later I will specyficate this DB (and byte by byte) on the HMI side.

My question is:
On the PLC side, what si the recomended way to create procedure to trigger alarms?

What HMI /Scada are you going to use? Makes a difference to what i would do

Additional to the above comment what PLC are you using. If i understand correctly you want to pack the alarm bits into a Word/DWORD and then bit strip at the HMI/SCADA level?

cjd1965 said:

What HMI /Scada are you going to use? Makes a difference to what i would do

Click to expand...

PLC is s7 314 and WinCC flexible 2008.

RheinhardtP said:

Additional to the above comment what PLC are you using. If i understand correctly you want to pack the alarm bits into a Word/DWORD and then bit strip at the HMI/SCADA level?

Click to expand...

Yes, I've done it before creating UDT, including this UDT in FB, then I've made a conditions to trigger all alarms I neded and in WinCC indicated the instance DB of this FB, but I'd like to know if it is correct/optimal, and how you Gentelmans used to do this..

Hi search siemens automation for example projects then come back and ask questions. I use an array of words which includes the alarm and alarm ack bits. The first set of bits is for alarms, the second for alarm acks so if you have 1 alarm word thren the array will be 2 words

for 256 alarms i use



In WinCC it looks like this





The followinng zip file is a csv you can import into wincc which will populate the 256 alarm list. Pay attention to the trigger tag addresses because there is a endian issue between S7 and Wincc

View attachment Alarms.zip

arturnok said:

PLC is s7 314 and WinCC flexible 2008.

Yes, I've done it before creating UDT, including this UDT in FB, then I've made a conditions to trigger all alarms I neded and in WinCC indicated the instance DB of this FB, but I'd like to know if it is correct/optimal, and how you Gentelmans used to do this..

Click to expand...

I hardly ever link bits to HMI. A wise old programmer once told me that he would fire me if he saw me doing this. He made me pack all bits into Status or Command words. Till this day i believe it is a good way and i recently saw the reason where an HMI did binding on bits. It slowed down the loading of pages due to all the bits having to bind the reference.

After changing it and grouping the bits there was a massive difference in the loading of the pages.

We are spoiled today with computing resources and programmers dont get trained to do efficient programming.

Thanks cjd1965 for exact explication. Downloaded. I'll analyze and memorize.

I've seen an example in WinCC help an some other examples before occupy a valuable time of all the people in this forum.

RheinhardtP said:

I hardly ever link bits to HMI. A wise old programmer once told me that he would fire me if he saw me doing this. He made me pack all bits into Status or Command words. Till this day i believe it is a good way and i recently saw the reason where an HMI did binding on bits. It slowed down the loading of pages due to all the bits having to bind the reference.

After changing it and grouping the bits there was a massive difference in the loading of the pages.

Click to expand...

Thanks for this advice. I'll change my thinkin to apply it from now.

Unfortunately I'm not so lucky to have a good programmer close to me, but exists this forum. That's why I'm here. And there is another reason to be here:
I want to do efficient and SAFE programming.

Once more, thanks a lot for your time Gentelmans, I appreciate all advices.

PLC Logic - Alarms

Hi,

I am a student in my final year.

I am currently writing a PLC program for a Level control rig.

There are 2 Storage Tanks;
Tank 1 has 2 level switches (High and Low level)
Tank 2 has 1 Level switch (Low level)

I am struggling to write LAD logic for this application.

What I am trying to achieve is the following;

High level switch on Tank 1 (overfill protection) will trip and flag an alarm in SCADA (Win CC 2008)

Low level switch on Tank 1 will trip but a timer will be used to allow for the tank to fill with water. Alarm will be shown in SCADA

Low level will trip when low water level occurs. Alarm will be shown in SCADA.

The system starts when Analogue output (Q124.0) for the pump is initialized.

I realize that this is probably really simple but I am really struggling with this and don't want my supervisor to think I am a complete idiot.

If any of you have any examples that you could upload/share, I would be extremely grateful.

Many Thanks
Thomas

Start a new thread !

Thomasbennie said:

The system starts when Analogue output (Q124.0) for the pump is initialized.

Click to expand...

Interesting terminology. Also no mention of tank 2 in your written description.

However, on a separate note, have you ever written a PLC program to do anything at all - if so what did it do?

Interesting terminology.

Click to expand...

LOL, that's what I thought