I need to read the PLC I/O data through AVEVA Plant SCADA 2020. The issue is that the PLC program does not assign memory addresses for each I/O point

[Dilhan]

I need to read the PLC I/O data through AVEVA Plant SCADA 2020. The issue is that the PLC program does not assign memory addresses for each I/O point. The system uses a Schneider M580 PAC, which is connected to the SCADA via TCP/IP Ethernet.

When I try to add an output like %Q1.1.20 in SCADA, it gives a "Bad I/O" error. I’m not sure how to view the Modbus addresses for each I/O point. Unfortunately, I cannot edit the PLC code because the factory operates 24/7.

Is there a way to connect the I/O directly with SCADA, or any method to monitor or identify the Modbus addresses for each I/O?

[Mnabil · Accepted solution]

Hello

There are different ways to connect, but I prefer to use OFS approach (OPC software delivered with Plant Scada)

What you will do , export the variables from PLC in XVM format and configure the OFS connection parameters and add the variable file into OFS configuration 

[Dilhan]

@Mnabil I connected it through the OFS tool; the connection was successful, but there were errors when importing tags into Plant SCADA Studio.

 

   

[Mnabil · Accepted solution]

Can you follow the setting in the attached print screens and you need to add name in PLC Tags 

[olivier_vallee]

Hi @Dilhan,

As others have mentioned, to communicate with the M580 with unlocated tags, you will need to use OFS (communications gateway) and the OFSOPC driver from Citect.

The easiest method is to export the tag config to XVM file, and have OFS use that file. Please note that if regular changes are made to the PLC code and tags, it is better option to enable "Tag Dictionary" and "Online Changes" capability in OFS. There is a good "TechNote" on the AVEVA website which walks through all the settings.

[Sheshan99]

Dear Sir ,

Can you tell me, How can i add the variable into OFS configuration ,And if you have sample XVM it will helpfull me to development.

[dnordenberg1]

OFS should be able to read topological addresses but I'm not absolutely sure M580 will let you do that since they are trying to move away from topological addressing. Otherwise you can do a online change and add those IOs as variables, that will not stop the program in any way. Just do a build when connected to the PLC and make sure online change is possible (should say "equal" and "built" at the bottom of the screen before you start adding code. Warning if you do a "build" while not connected you loose the ability to do online change and it will say "not equal att the bottom". Then you have to restore a backup or download the project from PLC to get in "sync" again.

[olivier_vallee]

Hi @Sheshan99,

You don't actually add the variable into OFS. But you do specify the variable tag database if "Data Dictionary" is not enabled in the PLC. 

So this is a setting on the PLC side, what this does is place a variable tags (and EDT, DDT) library into memory. This is then accessible by remote applications (like OFS).

If you do not have Data Dictionary enabled in the PLC, you must export from Unity Pro (or what ever PLC programming software you have) the Variable Tag database, to an XVM file. But bear in mind that every time you make a change on the PLC, you might have to export this file and update it on your OFS node. This could cause some communications interruptions. So the best and easiest option is to enable Data Dictionary, that way OFS will automatically get the latest variable tag list.

[dnordenberg1]

I have not used the Plant SCADA OFS (which I understand is built in?) but with the standalone OFS and you can also just type the topological address like %MWxx, %Mxx, %Qxx, %Ixx if the tag list is not fetched via dictionary or imported via XVM.

[olivier_vallee]

Hi @dnordenberg1,

The "OFS standalone" is basically the same version that is included with Plant SCADA, I guess it just depends on the version number. The Product feature set is is sized "Large". Latest version is V3.63SP3. The Plant SCADA installs the same version that is available from SE website, but the installer just uses custom serial number and product code to enable the license to make use Plant SCADA license.

It should in theory be possible to use direct addresses in Plant SCADA / OFS.

The OFSOPC driver in Plant SCADA communicates with OFS via OPC DA protocol.

It is best to use the tag name defined in the PLC (via Data Dictionary or XVM) in the communications definition.