Are there any issues that one needs to keep in mind when programming a PLC that’s supposed to be connected to an existing SCADA server (FIX)?

In this case, a PLC system is bought from one vendor, and the integration with the FIX-server is bought from another. Therefore, I would highly appreciate if you could tell me whether there are any specific requirements, which I should make on the supplier of the PLC system to make the integration easier.

 

The only issues I have encountered with such projects, has not been related to the PLC suppliers but more so on the SCADA suppliers. As you know system/software upgrades happen all the time and the SCADA suppliers, although claim the have all the drivers for all the PLC under the sun, they do not update their drivers all the time.

If the PLC in question is Siemens and it your comunications ptotocol is Ethernet, I encountered only 80% compatibility, granted this was 5 years ago, so they may have resolved the issue by now, but take nothing for granted. Best of luck.

 

You need to specify the protocol you wish to use to connect the SCADA. In my experience specifying a very basic standard protocol such as MODBUS is the only solution guaranteed to work. There are lots of other standard protocols but in many cases the implementation of the protocol is dependent on the PLC or SCADA vendors interpretation of the protocols specification.

I suggest specifying to both PLC and SCADA vendors what protocol you want to use and get them to both guarantee it will work. That way you can at least say to them to make it work if you encounter any problems. I also suggest you choose a protocol that is widely used by many vendors as this is most likely to have been used between different systems.

Hope this helps.
Regards,
Mark Mullins.

 

Thank you for the tips!

Kind Regards,
Farbas