TL140
Lifetime Supporting Member
So I am doing a project for my PLC networking class. We are using CLICK PLCs by Koyo. I am decently experienced, but my question is more about the control theory.
So I know how to use DFIU, OSR, Rising Edge contacts, etc.., pretty well. But I have never once used a DIFD or falling edge contact. I have always modified my logic to make my contacts be able to trigger an up-pulse, as i have always been taught that it was good practice.
Right now we are just doing a simple GS1 VFD control with the PLC and set-up of a N.O. Start button and a N.C. Stop button. (they are trainers with the equipment already mounted on them) The assignment is basically to let the motor run when the start button is pressed and let go. However, If the start button is pressed while the VFD is in reverse, Only let it run for 5 seconds.
I am one of those over achievers and know I can do this with simple seal-in circuits, but I wanna have a little fun with this thing. I have designed some ladder to basically start the motor with the start button. I can also stop it with the start button, if it is running. I also added safety features including the inavailability to change states of the motor while running.
But there is an unknown factor that I wanted to consult with you guys before I try it out since I have never done this before. It is acceptable to use a falling edge input for a NC contact so that it will pulse when pressed?? I will give you guys a sneek peek at the logic.
Also, with the drive, we are using setup 1 for the wiring.
So I know how to use DFIU, OSR, Rising Edge contacts, etc.., pretty well. But I have never once used a DIFD or falling edge contact. I have always modified my logic to make my contacts be able to trigger an up-pulse, as i have always been taught that it was good practice.
Right now we are just doing a simple GS1 VFD control with the PLC and set-up of a N.O. Start button and a N.C. Stop button. (they are trainers with the equipment already mounted on them) The assignment is basically to let the motor run when the start button is pressed and let go. However, If the start button is pressed while the VFD is in reverse, Only let it run for 5 seconds.
I am one of those over achievers and know I can do this with simple seal-in circuits, but I wanna have a little fun with this thing. I have designed some ladder to basically start the motor with the start button. I can also stop it with the start button, if it is running. I also added safety features including the inavailability to change states of the motor while running.
But there is an unknown factor that I wanted to consult with you guys before I try it out since I have never done this before. It is acceptable to use a falling edge input for a NC contact so that it will pulse when pressed?? I will give you guys a sneek peek at the logic.
Also, with the drive, we are using setup 1 for the wiring.