Hassman

Bump!

Hey all, So I took on the task of creating a C# application using the nModBus protocol to communicate between my ClickPLC and my PC. It worked, I am able to read data, write data etc etc. The problem is....I didn't realize that I have to continually "ping" (request read/write) the PLC for data, and I find this very inefficient, especially since it is only when the PLC input signals high that I want to register an event in my C# application. So software talk aside....I want my PLC to act as the master, and my PC to act as the slave. I want my PLC to communicate with my PC and tell it to read its data ONLY when it receives a high input signal. This would be much more efficient, especially in terms of a system process standpoint, and ultimately meets the purposes of my task at hand. Tips, ideas, thoughts? Thanks in advance!

Ok so let me this straight... I approach this set of push buttons and press PB5 (momentary push button) closing the circuit and passing current through. However, since it normally releases the second i let go, i add a normally open contact, which upon being energized closes as a result of the momentary push button being pressed and now in a sense "locks in" the current in the circuit until i choose to press PB6 (normally closed push button) Is that correct? Yeah, I play around with push buttons in my lab every monday , but i don't really get a chance to just play with them since we always have an assignment or something. It would be nice to get some free time just to play around with it and see how it all works. I should drop in next week and see if I can do just that! Thanks again for your help guys, really appreciate it!

Hey okiepc thank you very much for the diagram, and as I'm looking at it I'm wondering, why do i need the relay contact beneath PB5? Im sure i'm missing something but... If PB5 is NO and then i press it, doesn't it just allow current to pass through the circuit? why do i need the symbol for a contact beneath it? What does that do exactly?

Hey crossbow thanks for your reply! They aren't ladder logic symbols?? Sorry...I have been taught to draw ladder diagrams with those symbols, i guess ladder diagrams are different than ladder logic? Ok, so with that in mind, how does a latch work?? Im not sure, how do we draw one out and how do you write a latch around a pushbutton and pilotlight?

Hey all I'm starting right from scratch, and would really appreciate some help. I have a question straight from my textbook that we are taking up tomorrow, ive been rattling my brain but i don't know if i am designing the ladder correctly The question says: use NEMA symbols and design a ladder diagram that has an amber pilot light (PL3) on when NO pushbutton PB5 is momentarily pressed and remains on until NC pushbutton PB6 is pressed. I have attached a word document with my feeble attempt to draw a ladder diagram, if this is correct please let me know, and if not can you explain why and help me out??? ladder diagram PDF.pdf