Trend/Alarm Storage - how many bytes per record?

  • e.kislov

    e.kislov - 2019-12-13

    In Trend/Alarm Storage there is setting Maximum number of records.
    It seems reasanoble to also show how many PLC memory will be occupied by sqlite file in this case.

    Right now I want to know approximate memory space for 1 record in Trend/Alarm storage.

  • e.kislov

    e.kislov - 2020-01-02

    Still interesting in answer.

  • dkugler

    dkugler - 2020-01-03

    Originally created by: D. Kugler

    because it's interesting for me too, I started a test with 1000, 2000 and 3000 alarms max. and checked the file size of the sqlite.db. It looked like if no latch variable is used, one message takes about 164-188 byte. If a DINT as latch variable is included, it took rund about 200 bytes. So, I think it's depending on configuration and there is no fixed size. Maybe codesys stuff has an answer, what's the maximum size/alarm is?!
    If space in ram is a problem I would prefere to set the radiobutton to Maximum storage size. Fill the storage by blinking an alarm and have a look, how many alarms are in the history max.

  • AlexRoss

    AlexRoss - 2020-01-09

    Hello, Gentlemen

    Maybe I can help you with your question. I'm testing the storage functionality on the EPEC 6107 HMI with next trend storage configuration:
    Measure in every n-th cycle : 5 (100ms)Max number of vars: 5, but I use only 3

    Sqlite DB size for period 7-1-2020 17:1:36 - 9-1-2020 9:50:22 is 65974272 bytes


Log in to post a comment.