I am using a DL-250 from Automation Direct. I have figured out how to capture the time and date but am at a loss as to how to capture multiple occurances. I would like to display the last few occurances on a display that is connected to the PLC. I can capture the last occurance and store it in a memory location, but how do I shift this information down and insert the new information when the next occurance happens. My display looks at certain memory addresses for it's information and I think I would have to move the previous information to a new memory address and insert the most recent, so the display would show it. Any help would be appreciated.

 

I have an idea even though I am not to familair with the plc you are working with. reserve a bunch af data registers that can hold the data you want to look at.(make them all sequentail) You will need to have use a timer and an incrent command to move the data registers down. have each occurance activate one common bit and that same bit can increment your data down. Now on your display you can mabee create a screen that has a list of those data registers all in row. this way you can see all the occurances. I have done stuff very simulare to this using a mitsubishi PLC and HMI. Please Email me if you need more info: [email protected].

 

You will have to use a series of LOAD and OUT commands. You will need to set aside 2 more registers than you want to display for each catagory displayed. If you want to display the last 5 events you will need 7 registers, X 2 for the corresponding T&D stamp.At each event change (I assume you are looking at a status or coil)you will write to the first (selected memory location for the value and T&D stamp AND THEN in the same rung, you will LOAD register # 6 and then OUT to 7, THEN, LOAD register 5 and then OUT to 6, THEN, LOAD 4 and OUT to 5, Hope you get the drift. Work your way to 1 and display 2 as the most current.

 

Thanks David,

I was hoping for a shortcut, and to be able to do it without specifying how many occurances ahead of time, but that's probably not available. I understand what you are saying, and I can work with that, I was hoping for a way with less programming.