Do not perform historical logging on startup

Hello, I am using an Ewon Flexy 205 to store the results of product testing. I have used the BASIC program to log a new entry every time the Flexy gets new test data. All of the tag values for which I have enabled historical logging have the deadband set to -1 and the interval set to 0. The system is working correctly except that when the Flexy boots up, it adds a new entry to the historical log, which essentially looks like a duplicate of the most recent test. Is there a way to prevent the Flexy from adding this new line when it boots up? Thanks!

How is your BASIC program detecting new test data? Depending on how the data is polled, it might come in as 0 right at startup while it connects to devices on the machine network before updating to the actual value, which would trigger an ONCHANGE command since the data has changed from its previous state. You may want to configure another tag to control whether the test data logging script is running to prevent this.

The Flexy is connected to a CompactLogix PLC, and the BASIC code logs when it sees that the PLC has set a specific bit. I commented out the BASIC code’s LOGGROUPIO instruction, and the Flexy added a duplicate log entry regardless.

ONCHANGE “Send_Data_Trig”, “@send_data()”
// Receive the data sent from the PLC and store it into the EWON’s Log
FUNCTION send_data()
IF Send_Data_Trig@=1 THEN
// write handshake bit to inform PLC that logging has completed
// When the trigger has just changed, and is now low, PLC is indicating
// it knows data has been copied. Clear the handshake bit.

Can you attach a backup with support files so we can see the device’s full setup? You can capture one in eBuddy by checking “include support files” in the backup wizard.

Attached is a backup of the Flexy

Thanks, that was very helpful. I think the issue Q_Pass_Fail_Desc, which is a memory tag with a deadband of 0. Despite the fact that it’s set with topic RET so it retains its value, a mem tag configured the same way on my Flexy logs its value every time the device reboots. Can you try disabling deadband logging on this tag by changing it to -1?

Thanks, that was the problem. In case anybody else needs this, for whatever reason the browser interface didn’t let me set the logging deadband for a Flexy memory tag with topic RET. I needed to change the Flexy’s configuration manually by editing config.txt. In my case I just used FTP to do this.

Thanks again!

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