adccommunitymod (AutomationDirect) asked a question.
Created Date: March 02,2012
Created By: montrose
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I need to know how to write a bit of ladder to duplicate the results of pushing a manual push button. I have a Click system working, mostly, that moves a Sureservo drive and motor point to point and can not get the movement from the ladder program like I can from push buttons. I can connect buttons to X001, X002, X003, etc. to corresponding coil outputs of C121, C122, C123, etc. and the drive moves to the correct locations depending on what is in proper memory location. It moves as fast as I can push the buttons. Perfect. Now I need to call those same moves in the ladder program. I'm sure it will be only a one or two rungs but I have no clue. I need to call the moves from timers or C bits I think. If I call the C123 with a timer it just sits there. If I replace the C123 in the rung with Y207 output to a valve the valve works fine. If I replace the timer with the X001 the servo moves as it should. I have six positions to go to in the process and I'm stumped.
Created Date: March 02,2012
Created by: bcarlton
Would you like to post your program for us to help? Just zip it and post it here.
I was a little unsure what triggers the servo move in your description. It may be clearer when we see the program. Make sure that EVERY contact is labeled. Annotate each rung with your purpose.
Then make a not as to what you want to accomplish. Keep the first improvement fairly simple. We can help you with that and that may inspire you as to how to solve your other problems.
Created Date: March 02,2012
Created by: montrose
I appreciate you looking this over.
I have been trying different all sorts of combinations try to get this to work so if what is here is not very conventional then that is why.
thanks
Components;
Sureservo drive SVA-2040, servo motor SVL-204, PLC C008TR relay output , input module C016-ND3, output module C016-TD1, HMI EA7-6SM-R B & W touch screen.
(12) AVS-5212-24D solenoid valves
Created Date: March 13,2012
Created by: montrose
still looking for that inspiration......
No comments on this question? I posted the program as requested and nothing. This is the same response I got from the AD tech that wrote the demo program when I asked how to move to a second position. Was there a problem with the post? Do you need more info? Am I not asking the right question? Or is this actually not doable with a Click and a Sureservo? I have the complete program written with all the discrete inputs and outputs working and all I lack is a way to move the servo two or more times at the right times in the program. HELP please, this seems like it could be so simple.
Created Date: March 13,2012
Created by: bcarlton
I'm sorry, I missed that you had posted your program.
Activating a function using an input from a pushbutton means that the function will be ON for a significant amount of time, from the PLC's point of view.
But in rung 10 you also try to turn on C73 using an edge contact. This means that C73 and subsequent OUT commands will be ON for only one scan. It's fine to use a one shot but you may have to maintain the final OUT commands for more than one scan for the servo to recognize it.
Created Date: March 13,2012
Created by: montrose
I 've tried using a timer for a longer input of up to a second.
Created Date: March 13,2012
Created by: montrose
I understand that the edge contact is only on for one scan. I 've tried many combinations of timers, edge contacts, sub-rutines etc. and have not found a way to write this so it works. for weeks. Ive had countless people tell me that doing it the way I describe it will not work. I know that. The question is what will work? The question is what will make the C123 activate like it does with a switch? If I look at C123 in Data View after turning it on in the program with a 300 ms pulse C123 is on and I can follow the flow of addresses through the same paths the button follows. But the servo does not move. An OFF timer will produce the same pulse as a button, right? Am I using the wrong hardware? Is this even possible? I can not get a straight answer from Automation Direct.
Created Date: March 13,2012
Created by: bcarlton
I haven't used the servo so I can't give you more precise information. Sorry.
Created Date: March 13,2012
Created by: Do-more PE
You say it works with the pushbuttons. Do you have to hold the pushbutton in or is a single press enough?
Created Date: March 13,2012
Created by: montrose
A single press works and if I hold it down it works.
Created Date: March 13,2012
Created by: montrose
If I turn on the C71 with the button it needs a 100 or more ms to work.