adccommunitymod (AutomationDirect) asked a question.
Created Date: August 08,2012
Created By: marcks
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Hello, I have everything setup but need to link the ladder logic written to the plc to start or stop when the cmore micro touch panel start or stop button I have created is pressed. Would the _PLC_MODE SC11 work to start the start the plc and _PLC_Mode_change_to_stop SC50 work for the stop? I have a time-based ladder logic program built in the click plc software. All it is doing is turning on a valve then counting down a predetermined amount of time. The click PLC is a C0-00AR-D and a 6 " c-more display. Thank you for helping out.
Created Date: August 08,2012
Created by: bcarlton
You have the wrong idea about PLC operation. Once your operation is complete in the PLC then the code should just do nothing else. The display cannot be used to start and stop the actual scanning of the program.
Created Date: August 08,2012
Created by: marcks
Could I use the drum function to start and stop the timer. If I complete the drum function then could I wait for a button on the HMI to be pressed to start the drum again?
Created Date: August 08,2012
Created by: deep6ixed
I'm trying to understand what exactly you want the PLC to do. Do you want to prevent the start button from doing anything for a set amount of time after it is pressed or do you want the output to the valve to open for a set amount of time for each button press?
Created Date: August 08,2012
Created by: bcarlton
So describe what you want the output to the valve to do. Is this in response to an operator input? Detail the steps one by one. For example (and this may not be correct for your application)
1. Operator presses a button
2. The valve is turned on
3. After a certain amount of time the valve is turned off
4. Go back to step 1
Created Date: August 08,2012
Created by: marcks
So describe what you want the output to the valve to do. Is this in response to an operator input? Detail the steps one by one. For example (and this may not be correct for your application)
1. Operator presses a button - Via HMI
2. The valve1 is turned on
3. After a certain amount of time the valve1 is turned off
4. Valve2 is turned on
5. After a certain amount of time the valve2 is turned off
4. Go back to step 1 and wait for next operator press
This is what I want to do but I have several valves however there are a total of 10 valves in the sequence. The main issue is how to reset after everything is finished and wait for the next operator press.
Thank you for your help.
Created Date: August 08,2012
Created by: bcarlton
When the HMI button is presset set a bit (Cxxx). The turning on of this C bit starts the sequence. When the last part of the sequence (valve 10 turning off?) has taken place reset the bit.
If you want to make sure that the sequence does not start automatically even if the PLC was powered down midway through then make sure that the column 'Initial value ' in the Adress Picker says 'Off ' and that the column 'Retentive ' says 'No ' for the C bit chosen.
Created Date: August 08,2012
Created by: marcks
When the HMI button is pressed set a bit (Cxxx). The turning on of this C bit starts the sequence. When the last part of the sequence (valve 10 turning off?) has taken place reset the bit.
Created Date: August 08,2012
Created by: bcarlton
Do not attempt to write to an X or Y reference. Write to a C bit (the one I mentioned) using 'set On ' in the object type. After pressing it you will see the button change to its ON state while the cycle is taking place then turn back off (if you program the Click as I suggested)
And it would be best to get the Click program running as you want it first before worrying about the display.
Created Date: August 08,2012
Created by: marcks
Do not attempt to write to an X or Y reference. Write to a C bit (the one I mentioned) using 'set On ' in the object type. After pressing it you will see the button change to its ON state while the cycle is taking place then turn back off (if you program the Click as I suggested)
Thank you so much!
When I set a C bit in the PLC there is no issue. When I try and reference a C bit in C-more micro if I want to stop the process mid-way I can use another button to set the same C bit to off and the process will exit correct?
Created Date: August 08,2012
Created by: marcks
Or should I use the PLC_MODE_CHANGE_TO_STOP at SC50 for a stop button?