Hi everyone, have a nice day!

I am working on Power management system (PMS) and i met a trouble when i connect gateway to WinCC V7.4. This system has 680 power meters, we use 40 gateways (RTU >>> TCP/IP) to connect with all power meters. And the last gateway connect with WinCC via Modbus TCP/IP. 

In TAG MANAGEMENT in WinCC, we made 680 Modbus TCP/IP connection for 680 power meters (different IP Address). But i don't know why i couldn't connect them, maybe because there are too much connections that winCC can't work  or something else. And when i try to connect less than 500 connections, it was working. 

So, anyone can tell me that HOW MANY LIMITTED CONNECTIONS WE CAN CONNECT in WinCC for Modbus TCP/IP

This is the first time i've worked on PMS. I hope to get more experiences and advises from you

Thank you so much