adccommunitymod (AutomationDirect) asked a question.
Created Date: April 13,2013
Created By: ironband
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Hi all, I need a little reality check. I 've tried searching out the answers and I think I know, but I need to know for sure before I finish designing and start ordering parts. I'm designing a machine and plan on using a Click PLC to control its operation. It will include a stepper using a STP-DRV-4850 on port 2 as well as a GS1 VFD controlling an inverter duty motor on port 3 (or possibly just using presets and digital control, haven't really decided yet). First question - am I correct in my understanding that if I am using a Click PLC without any interface and I program the Click PLC using the software, and in that program there is a particular instruction which, say, instructs the stepper to move at a particular speed, that changing that speed in execution would require that I alter the program on my PC and then upload it to the PLC again? Assuming that the answer to that question is yes... If I add a Cmore EA1 Micro Panel to port 1, would it be possible, via 'recipes ' or some function, to have the operator of the machine select a function (say, A, B, or C) on the screen which would tell the PLC "when you get to the instruction with the stepper, run it at speed A, B, or C "? I believe the answer is 'yes ', but I just want to be sure that a cmore micro will let me preset some parameters for the stepper and VFD and utilize those based on operator selection. I also want to be sure that a cmore or some such interface is necessary to do this without bringing the computer out to the PLC to upload the program each time a change is needed. Thank you in advance for your expertise! Andre
Created Date: April 13,2013
Created by: bcarlton
If the speeds are known beforehand they could be selected by inputs to the Click, just as in the VFD speeds can be selected from a list via inputs. Simple logic could select from the known settings.
Created Date: April 13,2013
Created by: plcnut
If that is all you need the Cmore for, then use a 3 position selector switch to select each speed. Or, you could use an analog click and a speed pot.
Created Date: April 14,2013
Created by: ironband
Good point, bcarlton. And thanks for the perspective plcnut.
Initially, using a couple of three way selector will probably work, one for the steeper and one for the vfd. But down the road I may wish to add more options for speeds, so would I be able to do that with a cmore? I don't want to have to create a dip switch bank if I get to the point where I need 10 different options.
It might also be nice to display some info on the screen, though that wouldn't be critical. The cost is pretty low.
Created Date: April 14,2013
Created by: bcarlton
But down the road I may wish to add more options for speeds, so would I be able to do that with a cmore? I don't want to have to create a dip switch bank if I get to the point where I need 10 different options.
It might also be nice to display some info on the screen, though that wouldn't be critical. The cost is pretty low.
All are excellent reasons for an HMI. PLCnut and I were just pointing out that in a known, permanently limited application it is better to keep it simple. But the HMI does provide for a lot of flexibility as you point out.
Created Date: April 14,2013
Created by: ironband
Cool, thanks. I may initially build with the selector switch and then upgrade to the cmore later. At least it is all pretty modular. Thanks for confirming that it will do what I need it to do. I can proceed with confidence. Sorry if the questions seen lame, I'm new to this while computer control/plc thing.
Created Date: April 15,2013
Created by: Philip Potts
Ironband,
The answer to question one is "Yes. " You will have to reprogram the PLC to change the speed. However, as Bernie and PLCnut have pointed out, there are ways to accomplish your task with selector switches.
The answer to question two is also "Yes. " You can use the C-More Micro to control the speed of your stepper motor and VFD or whatever else you might need. Within limits of course.
Besides what others have offered in the way of advice, I would like to add the following. You can quickly spend more on switches than the price of the C-More Micro alone.
I completely rewired a machine a few years ago and I control the whole machine with a C-More Micro. Without the C-More I would have needed a start button, a stop button, a jog button and three three-position selector switches. I used the C-More and two E-Stop buttons.
Good luck with you project and let us know if you need any help.
Created Date: April 15,2013
Created by: kewakl
If your motor speed is in a DS, DD, DH, DF memory location, you *could* simply connect your PC and change the value from a Dataview.
Created Date: April 15,2013
Created by: ironband
Besides what others have offered in the way of advice, I would like to add the following. You can quickly spend more on switches than the price of the C-More Micro alone.
Wow, I looked at the selector switches and you 're right! It seems like it might be more economical to just get the Cmore and a single emergency stop button and be done with it. I mean, 2 three way selectors, a start/stop,
Thanks also for directly answering my questions. Now all I have to do is finish my drawings for the machine shop and I can get this project moving.
Andre
Created Date: April 13,2013
Created by: ironband
Hi all,
I need a little reality check. I 've tried searching out the answers and I think I know, but I need to know for sure before I finish designing and start ordering parts.
I'm designing a machine and plan on using a Click PLC to control its operation. It will include a stepper using a STP-DRV-4850 on port 2 as well as a GS1 VFD controlling an inverter duty motor on port 3 (or possibly just using presets and digital control, haven't really decided yet).
First question - am I correct in my understanding that if I am using a Click PLC without any interface and I program the Click PLC using the software, and in that program there is a particular instruction which, say, instructs the stepper to move at a particular speed, that changing that speed in execution would require that I alter the program on my PC and then upload it to the PLC again?
Assuming that the answer to that question is yes...
If I add a Cmore EA1 Micro Panel to port 1, would it be possible, via 'recipes ' or some function, to have the operator of the machine select a function (say, A, B, or C) on the screen which would tell the PLC "when you get to the instruction with the stepper, run it at speed A, B, or C "?
I believe the answer is 'yes ', but I just want to be sure that a cmore micro will let me preset some parameters for the stepper and VFD and utilize those based on operator selection. I also want to be sure that a cmore or some such interface is necessary to do this without bringing the computer out to the PLC to upload the program each time a change is needed.
Thank you in advance for your expertise!
Andre