Morse Coding a horn in ladder

[Lancie1]

The toggle is a Maintained Contact until pressed again, which leaves the lights of the button on the HMI ON until pressed again....or if I press another button which calls for a reset of all other button memory bits.

A true correctly-defined maintained-contact switch cannot be reset by any other instruction. It must turn itself off (open its own contact), otherwise it stays at "1". "Maintained" means exactly and only that the state is maintained or held, until a user operates the same switch again.

Someone has mis-labeled these HMI buttons if they think it can be reset by other means, and still be called a "maintained-contact" pushbutton. This error is not surprising because often the meaning of words is lost when technical instructions are translated from language-to-language.

 

[kamenges]

Originally posted by Lancie1:

A true correctly-defined maintained-contact switch cannot be reset by any other instruction.

You've been playing the game long enough to know that truth and convention are two very different things. What mitureg is describing is the way that any of the peer communication non-I/O HMIs that I have ever used work.

What the HMI is doing is looking at the state of the memory location when the button is pressed and changing it to the other state. It is maintained in the sense that releasing the button will not change the memory location value back to the value it was prior to the button press, as a momentary button would. There is nothing preventing another source from changing the value of the memory location in the plc, be that a programming station, another HMI or plc logic. If you need to have the HMI truly hold the value of the bit you will likely need to use one of the I/O-type drivers such as the implicit drivers in AB. With most of those an internal copy of the data is held in the HMI and that is what is used by the HMI to make decisions.

Keith

 

[Lancie1]

Yes, you are right. There are people working every day to corrupt the little bit of logic and reason left in the English language. Eventually when every word has 1 million meanings for 1 million different people, no one will be able to communicate. Civilization will fall back into chaos.

 

[kamenges]

What do you mean "back into"?

 

[jdbrandt]

Hi all, thank you for reading this post. it's been a while since I posted a thread. I hope you are well.

I have this new project requirement for naval sound signal with a horn in case of restricted visibility.

We need to alternate short-short-long or long-long-short values. These must then be spaced with a delay of about 2 minutes.

The client wants a push button that engage a sequence that will repeat until the switch is disengaged.

We have to use TwidoSuite for the project, but if anybody could explain the concept in Allen-Bradley that would be fine.

Much appreciated,
Mitureg.

Term definition of Restricted Visibility and Naval not withstanding, I certainly hope this is a HomeWork assignment, because it conflicts with both the International and Inland Rules Of The Road.
[Before I was an Automation Engineer, I was a USNavy Petty Officer, and the horn sounds and patterns are very specifically detailed as to their meanings; not to mention the definition of a 'short' and a 'long'.
http://www.navcen.uscg.gov/?pageName=navRulesContent#rule32 $ 33

 

[mitureg]

The messages are one long blast, two long blast and one long blast followed by two shorts. The initial post was just to make things simpler as a starting point.

Thank you for the documentation.

 

[Lancie1]

What mitureg is describing is the way that any of the peer communication non-I/O HMIs that I have ever used work.

The better HMI software packages that I have used have an actual valid Momentary On, as well as the Set On and Set Off that you and Alex are describing. See attached picture. The cheaper packages do not have these extra functions, so get by with a ******* version.