SD Card Data Logging - Help needed

[russedwards]

Hi everyone

 

I have got myself a problem that I am having trouble figuring out.

 

I am using a V350 as a data logger. The V350 is logging MI's, and ML's to a data table. The logging is working fine.

 

My application requires a result to be logged every 10 or so seconds, therefore I am filling the internal memory of the V350 pretty quickly. I would therefore like to use the SD card as the memory of the logged data.

 

I currently have a net set up in my ladder to copy the data table to the SD card when the memory is 70% full. What I would like to do is to be able to append this Data table stored on the SD card with new data as it is recorded in blocks - for example - I record 1000 lines of data to the SD card, then when the data table reaches 1000 lines again, add this new data to table saved on the SD card. I can write to the SD card each time a result is recorded if it is more appropriate.

 

Is this possible?

 

Also, sometimes, we may need to access this same data via dataXport. Can I download a copy of the data saved on the SD card using dataXport rather than using the SD card suite? The scheduled download function in dataXport makes it desirable for this application. We would like to download a copy of the table and leave the SD card data unchanged. 

 

Thanks

[Alexander]

This is absolutely possible, when saving a full data table to the SD card there is the option to overwrite or append the current information. This will allow you to continually store information to a single file within the controller..

 

DataXport is only for current information within the memory of the controller, it unfortunately cannot access files on the SD card. As you mentioned one option is to use SD Card Suite though this requires the operator to manually connect to the unit. One other option is to send the file via email. All files on the SD card can be added as an attachment. This will allow you to manually trigger a send from the controller, send after a number or writes to the SD  card, or write based upon a time schedule defined within the controller.

 

A helpful example for using the SD card is the V570_SD_Card_Demo which can be found in the Examples folder in VisiLogic under the help menu. Although you will be using a V350 the ladder to accomplish these tasks are the same.