Mervis IDE date/time

  • My UNIPI Neuron PLC is running Mervis soft, it is not connected to the internet and there is no NTP server in this network.
    PLC is running a scheduler, users are interfacing to controller through modbus TCP.
    Users need to be able to update date and time in PLC.

    Is it posible to achieve thist by Mervis IDE?

  • @xbastek The PLC has a real time clock. You can set them. Right click to PLC -> PLC Operation -> PLC Setup -> Time setup.

  • Hi @David , thanks for your reply. I know this time stetup.
    The problem is that the user claims that this clock is drifting.
    They claim that plc developed already 2 hours of delay in 2 months.
    As far as I know, when RCT is working correctly this is not possible?

    They want to be able to adjust time and I have to solve this problem somehow.

  • @xbastek This is a very strange behavior. I will try to find out what it might be. The RCT has a capacitor and should stand without power for about 9 days so I do not see much opportunitys for any error with time. Doesn't you really have the ability to connect somewhere for the real time?

  • @xbastek To us it seems like the most likely explanation is that the timezone settings in IDE have been changed to users local time. The crystal used within the RTC is of quite high precision, and the time drift we have observed in testing has been on the order of one second in several months. In addition, the particular nature of the time drift (that is, in hours) would point this way as well.

    The Mervis IDE as well as Neuron itself runs on UTC, but this is possible to change in the PLC setup, which will naturally skew the clock. Would it be possible to check that the customer's PLC time corresponds to UTC? If not we would recommend to set it back to UTC and see if the issues persist.

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