Mike_ (Customer) asked a question.
I'm trying to mimic a classic physical Start/Stop push button (push to start push to stop). I want to have start/stop control of a motor contactor, simple ladder logic is: IF Start_PB OR Coil energized AND NOT Stop_PB then energize coil.
---- Start_PB -------------------------------------( Coil )
| |
----- Coil -------- / Stop_PB ----
However I tried to use an indicator button where each button's indicator was the Coil. The problem is that then the stop button is visually drawn in its pushed (ON) state the same time the start button is pushed because they both use the same indicator variable. My current remedy is to create another variable and put another rung in my ladder to create an inverse of Coil's state like so:
---- / Coil -------------------------------------------( Coil_Off )
Then I make the stop push button's indicator be set to Coil_Off. Ugh, this is alot of extra work since I have a lot of start/stop buttons to program.
What I want to know is if there is a better way to do this? I would like the Stop_PB indicator button to have the inverse state of the Start_PB indicator button but I don't want to have to manage a separate variable for the stop push button's state.
I have also tried to make the stop button a momentary off type but I get the same results in the end.
I hope I have made sense.
You should be able to reverse the colors in the Object Properties box. Start PB (on color green) (off color gray or whatever you like) Stop PB (on color gray) (off color red).
Good point, that is actually what I did at first and what made me realize there was a problem. I have tried many color combinations but to no avail. The ultimate problem is the shading that is automatically drawn by the c-more hmi on the edge of the button to make it look pushed in or not. Any indicator button seems to have its outer edge drawn in a pushed down state visually when its indicator is true and draws the outer edge in an non-pushed state when the indicator variable is false regardless if I modify the ON/OFF colors.
You are right. You could use a Frame of None. But that may be to plain for your project.
Okay. hmm..
What would be nice is if the indicator button operated like Object Visibility Option where you could control its indicator (if it was "pushed") based on true or false selection. That would open up alot of freedom for code.
Would I post another thread for a feature request for that? Or are there other channels for that?
how about use same button press once turn on and green, press again turn off and gray? probably have to do logic in plc. I prefer this over twice as many buttons with limited real estate.
Just a thought
I appreciate that, I wanted both buttons visible at all times for clarity to the operator. Our operators keep getting confused sometimes as to whether a single button is telling them what state they are in now or what state the button will move to so I wanted two buttons.
What you probably want is the Step Switch under the Button pallet. The Step Switch is a little more flexible than the Radio Button.
With the Step Switch you can toggle between two bits (Start and Stop). These can have independent colors (Radio colors are the same for both buttons). You could set the stop color red for both on and off and set the Start color green for on and off. You could provide an indicator light for the start status bit as green for running and red for stopped if additional clarification is needed.
This approach maintains the red stop, green start functionality while allowing the start/stop bits to be toggled.
Edit: I thought this would work but it looks like if one of the buttons is repeatedly pressed, it will toggle to the other state, which is not what you want.
Edit2: You can use the Switch Button to toggle one bit. With this approach, you'll get the start/stop you're looking for but will require PLC logic to toggle between start and stop.
Example:
C102
| |-----------------------(Start)
C102
| \ |-------------------------(Stop)
I did try and I concur with your edit's, I don't so much mind that the start button works as a toggle but the stop button working as a toggle is probably a bit dangerous.
Interesting, I dabbled with the step switch but I admit it didn't push it very hard. I will try what I'm attempting with that button type and let you know. Thanks.
Hi Mike,
Here is a post on the Start, Stop, Jog circuit and programming using the EA9 HMI.
https://accautomation.ca/c-more-ea9-hmi-series-panel-first-program/
YouTube Video:
https://youtu.be/5c8ZsdK5dak
Regards,
Garry
https://accautomation.ca/series/c-more-hmi-series-panel/