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Maximum number of rows in data tables?

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Hi all, just started using V350. My application is primarily temperature data logging and a simple program to output alarms whenever there are deviations on the temperature. I have not seen in the manual regarding the maximum number of rows that can be created on the data table. However, through trial and error, I was able to set it at 32767. Anything higher, this error 'Rows: numeric characters only.' appears. Some threads say that the max memory for data tables is 120k. I'm just confused since even with a single column set to 'byte', the data table does'nt accept row numbers higher than 32767. I was planning on creating multiple data tables to preserve the data longer before being overwritten. Would appreciate if somebody has something better. Thanks!

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VisiLogic Help clearly stated about 120K reserved for tables.

Max number of columns - up to 32 (when enter 33 - you have message about limit).

Max number of rows limited to 32766.

Better is keep table smallest and use SD card to save data from table.

Use only Data Table in memory, you have a chance to lost data in case of EMI or other disturbance.

You always can check Data Table memory status from Data Table->File->Memory Requirements.


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You do not say what frequency you are wanting to take temperature readings and store the information, but data tables are not the correct place to store large amounts of data. How we handle this situatuon at my company is to use a data table for local decisions and on screen annunciation of short term data only. Every time you record a temperature store this to a data table (just before you store copy the entire data table and then paste it one row down so that you are not overwriting older data in your table). Yes you will eventually lose the oldest data as it gets pushed out the end of the dta table. Then you would have data from the newest to the oldest for the 32,000 + readings to show on screen locally and manipulate as to what was happening now and in the near past. Then after this store, save the same information as a delimited line into a .CSV file on the SD card. In our case we change the file name once per day making the file name of the file to be limited text and the complete date so we can locate data easily for an event based on the day/month the event occured.

When saving files in a .CSV on an SD card you are not bound by the file number limitation that is published in the help files and I have had upwards of a thousand(s) files in a single folder. (PS. I screwed up and made a new file name every 24 minutes and not every 24 hours so this was completely by acident I would not chose to have 1000s of files in the same directory on purpose). At this point the customer can remove and replace SD cards as needed to get their long term storage of data or you can send them the files if you have the communications capabilities (and speed) to get the .CSV files to the custoemr over ethernet or modem.


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