adccommunitymod (AutomationDirect) asked a question.
Created Date: October 13,2005
Created By: Tectron
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Hello, I am new to plc's and touch screens so please forgive me if I sound a little ignorant. What I am trying to do is have an on and off switch on my touch screen. I have successfully gotten indicator lights to work with corresponding outputs, but I am having trouble with the switches. For my start switch I have a pushbutton set up as momentary on and the address as X0 to correspond to my ladder program. For my stop button I have a button set to momentary off address X1. Nothing happens in the plc when I press them. I also have physical switches wired to the plc, that’s how I know the indicator lights work on the touch screen. Do I need to program the plc differently when using an Ez-touch screen? Or am I just overlooking something simple. Any help is appreciated. Thanks
Created Date: October 13,2005
Created by: bcarlton
Do not address the buttons on your screen to inputs (X). The state of the actual physical input will overwrite it. Instead addrtess it to bit registers (C). Use that as your contact in the logic.
Created Date: October 13,2005
Created by: Tectron
Thanks, Could you give an example. I havent used bit registers yet.
Created Date: October 13,2005
Created by: bcarlton
In the EZTouch, go to the control you assigned to a tag whose address was X0. Change the tag's address to C0. Now go to your logic. Where you use X0 change it there to C0. Try it out. Then start changing the rest.
Created Date: October 13,2005
Created by: Scott_George
In your easy touch software go to Setup , then tag database , then Add/Edit . Create or modify your switch by giving it a tag name ________ , then select datatype Discrete then put C0 for your plc address. Click Add New Tag , then close .
Now your tag is there. In your PLC program you can put C0 in parallel (OR) with X0 and either (or) will turn on your circuit.
Good Luck!
Created Date: October 13,2005
Created by: Tectron
Cool, Thanks for the help!
I got my start button working now, but for some reason my stop button won't work. I paralleled C0/X0 (start) and C1/X1 (stop) in my ladder, and changed the addresses in easy touch as suggested. I tried changing the actuator type but it didn't make any difference. ???
Created Date: October 13,2005
Created by: Tom Jenkins
You can't directly access I/O from the EZ Touch. Use C (coils) instead.
Created Date: October 13,2005
Created by: bcarlton
Can you post your start/stop logic.
Created Date: October 14,2005
Created by: Scott_George
Tectron:
If you are doing a stop/start circuit then you do not want to parallel your stops. If your starts are C0 (eztouch) and X0 start pushbutton then you will put those in parallel. But, you will want to then put your stop switches in series so that when pressed will open your circuit.
Also, if your stop switch is physically wired NC then you will want your contact in your rung to be NO because it will always be on until pressed.
Your logic should basically be:
C0 OR X0 and X1 and not C1 out Y0.
When :
C0 = start on EZtouch (momentary)
X0 = start PB (momentary
X1 = stop PB (momentary wired NC)
C1 = stop EZtouch (momentary)
Y0 = output
Created Date: October 14,2005
Created by: Tectron
Here is what I have been able to get to work. C0 X0 and Y0 in parallel(all normally open)then X1(normally open)C1(normally closed)and X2 normally open(this is my low level switch)then Y0 out. If I make C1 Normally open it keeps the circit open. Is there a differant way or is this correct? I want it to work but I also want the code to be normal.
Thanks
Created Date: October 13,2005
Created by: Tectron
Hello,
I am new to plc's and touch screens so please forgive me if I sound a little ignorant.
What I am trying to do is have an on and off switch on my touch screen. I have successfully gotten indicator lights to work with corresponding outputs, but I am having trouble with the switches.
For my start switch I have a pushbutton set up as momentary on and the address as X0 to correspond to my ladder program. For my stop button I have a button set to momentary off address X1. Nothing happens in the plc when I press them.
I also have physical switches wired to the plc, that's how I know the indicator lights work on the touch screen. Do I need to program the plc differently when using an Ez-touch screen? Or am I just overlooking something simple. Any help is appreciated.
Thanks