Topics created by johni2212

Hi @johni2212,

Despite all the advantages, this variant has one disadvantage, which is that you have to upload the terminal and all programs to all controllers at the same time.
In general, the web interface (either local or external version) should be uploaded last.

If this is a problem and you do not have a lot of shared data, I recommend choosing Modbus TCP or SSCP communication between the controllers and then using a local web server.

Best regards,
Antonin

Hello @johni2212,
which version of MervisIDE and which version of MervisOS image do you use?

Thanks,
Martin

Hi everyone,

In the current version of Mervis OS 2.4.2.4, writes to the card already occur at least, according to the set interval for storing retain variables.
For a similar reason, the history is newly stored in RAM (data is lost after the power is disconnected or restarted), which does not matter in combination with the cloud-based Mervis DB.

If you disable writes to the internal storage (SD card), there are two possibilities of what can happen (depending on how you disable the writes):

Mervis RT always unlocks the storage when writing retain variables, writes and locks the storage again for writing (basically the same behavior as now) Storage will be permanently locked and retain variables will not be writable. Likewise, it will not be possible to upload a new assembly (program) from Mervis IDE.

In general, I recommend purchasing an SLC card with a longer lifespan and resistance to random power outages, etc., for the operation of the controller.
You can read more about this issue in this article.

Best regards,
Antonin, Unipi