Automatic backup SW

[alextu]

Hello

I want to develop a module that performs auto backup for Unitronics PLCs.

Is there any conventional way to perform auto backup?  

[Saragani]

What do you want to backup?

Tags? Project in PLC?

 

 

[alextu]

Hi,

I would like to upload the values of the tags to the existing project and in some cases to upload the project from the PLC,

Is it possible?

[Saragani]

Well, the communication driver does allow reading the tags (Operands), but you'll need to read each type (MI, MB, ML) by itself, or make an array of requests.

Off course they will not all fit into one response from the PLC, so the communication driver will automatically split them to smaller ones.

 

However, you need to take into account that the values will probably change while the PLC is running (since it is not an atomic action), so you should change the work mode of the PLC from Run to Stop, only then read all tags, save it somehow in a format you know, so you can then restore your backup (using write operands request), and only them Run the PLC again.

Some of the System operands are not writable, so you will not be able to set them a value.

 

Uploading a project from the PLC is much more complex, since not always the project was downloaded with an upload option. Furthermore, it involves a lot of communication commands which are not trivial.

 

It have not worked with a Vision controller for a quite some time, but I remember that there is an option to trigger PLC backup to SD from Ladder.

There is an element in Ladder, under the SD ladder elements menu, called Clone.

Once you have a clone of the PLC, then you can restore it on that PLC or on a different PLC. 

If you want to backup the clone to a computer (so it won't only be on the PLC), then you can use the communication driver (using the SD class, plc.SD.ReadFile) in order to read the file,

or manually connect to the PLC with SD Card Explorer and download the file to your computer.

The SD Card explorer is just a UI wrapper for the SD Class, so anything that can be done with the SD Card Explorer, can be also done with the SD class.

[alextu]

Thank you for the answer!

I would like to perform Upload to the project with the current tag values. The most important values for me is the parameters (such as alarm parameters, proccess parameters, setpoints). Those values do not change that frueqent thus i don't really need to stop the program.

Cna please specify the commands for the upload?

[Saragani]

Well, in general, the commands do the following:

* Check if upload exists

* Allow the Switch to "Flash access mode" (where you see the Visilogic Eye icon on the PLC)

* Read the size of the upload file from the PLC (reading binary data)

* Read the binary data of the upload file from the PLC (as byte array) and save it to disk.

* Decompress the binary data

* Connect to the decompressed DB file.

* Read images and fonts headers from the PLC

* For each font and image in the PLC, read the image (Header + Binary data), and update the Data Base with the uploaded font / image.

 

I wouldn't recommend it due to the complexity.... Once you have uploaded a project (even from Visilogic), the project doesn't change unless you download a different project, so there is no need to upload it again.

In my opinion, Cloning the PLC from the Ladder Utility, and then uploading the file to the PC is the best option, since you get a complete backup of the PLC, including the upload data.

I think that the Clone also has the tags value inside (You can confirm that with our support).

You can also contact them regarding this issue, and they will be happy to assist.

[Ofir]

Hi,

If you are using the Enhanced Vision PLCs then basically it comprises SD/Micro SD card slot.

The ladder offer a utility to clone the PLC (program, data tables, operand values) to a file. You can trigger this utility using a schedule or other method.

You can find this utility under Ladder --> SD menu --> clone