How many PLC can connect to Compact HMI 800 via Modbus TCP/IP
I want to use Compact HMI 800 for a Power Management System. I have to connect Compact HMI 800 workpalce to 93 multimeter via Modbus TCP/IP protocol.
I use the Wizard Compact 800 6.0 to design this project. And I realize that I cannot add more than 75 multimeter to the control network. Please open the attachment to see it in detail.
Do you have some advice for me?
The best way is to put a PLC in between(e.g AC500) and take the data from this PLC instead rather than connecting so many device on Modbus TCP/IP directly to CHMI.
Since you have 93 meters, the area must be wide and distributed, so consolidate all the multimeter data to these AC500 PLCs (may be you use two ac500's) and then CHMI talks to these AC500 PLCs via either OPC or Modbus TCP/IP.