QuickTanks (Customer) asked a question.
Use Button Value to Compare Pressure and Control PLC Output
I have a EA9 and need some guidance in creating a set of buttons. I need to have 6 or 8 different pressure options for the operator to select from. Once he selects his pressure and pushes his test command button, his test command button will start the pump. I need the PLC to know his pressure selection so it can compare the selected pressure to the analog signal of the pressure transmitter. Once the selected pressure is achieved, the PLC will turn off the pump.
I'm using a Click C0-11DRE-D and a C-more EA9-T10WCL
Thanks in advance for any guidance you can give.
You could use different buttons that are connected to different "C" bits in the PLC to know which pressure is selected.
Or maybe a "Radio Button" in the HMI will do what you want.
Or possibly you can use a numeric entry and then a "go test" button and the PLC just reads the numeric input value and is only triggered to start with the button press.
+1 Pouchesinc,
A radio button on the HMI would be a good option.
Attached is the program for the above.
Regards,
Garry
https://accautomation.ca/series/c-more-hmi-series-panel/
Pressure Select
Thanks for your help. I may have been overthinking it a bit.
I will admit, I pretty much don't know anything about automation, but I am more than willing and it's something I've wanted to learn for a while, so my boss agreed to let me take on this project.
On the PLC, do I need to create a bunch on latch/unlatch rungs to only allow one button to be selected at a time? Or, is there an easier way?
Hi QuickTanks
You would probably just use a COPY instruction to move the value to the active area that you are looking for the pressure.
Here is some additional information on the Click PLC for you.
https://accautomation.ca/series/click-plc/
Typically writing the code is the last step of the program development.
https://accautomation.ca/five-steps-to-plc-program-development/
Even though you are familiar already with the process, I would still write out the sequence of operation that you want. This can also apply to the HMI. How you go between pages etc.
I hope this helps you out.
Regards,
Garry
https://accautomation.ca/programming/plc-beginners-guide/
The radio button does all that work for you. you can set it up that each button has it's own tag or use a 16 bit int and each bit represents a button.
This is all great information. I appreciate everyone's willingness to help out.
I am doing something similar with a Cmore EA3 screen for my train project. The EA9 has the same features. Using the Recipe function you can move a set value into a PLC value with the press of the HMI.
In my case the selections are 1,2,3,4,5,6,7, etc.. but you can make the numbers anything you need.
Thanks again for everyone's help. I'm bringing this back on a related question.
I have the HMI buttons and some PLC logic working. Once the button is pressed, my outputs turn on as should. Once the pressure transmitter reads the programed pressure, I have an output that turns on. I need this output to stay on, but all previous outputs need to be turned off as well as the selected button on the HMI.
My question is, how do you turn off the output coil? I can do it by deselecting the button, but I need it to be automatic at the selected pressure.
Simple answer without knowing much about your program is to make a C bit for Test_done ( I'll call it C100). Probably have to use a set out for this. Then add c100 in the ladder of the outputs you want to turn off. Then use RST c100 when you start your next test to turn c100 back off or before if only need the 1 output to stay on for say 10 secs.