Is it possible to establish communication between Modbus TCP Master(YokogawaDCS) and Modbus RTU master (Ovation DCS) using modbus gateway…if so what is best gateway converter

 

Yes, you can use ICC's ETH-1000 to do this. Details and pricing can be found on its product page here:
https://www.iccdesigns.com/millennium-series/10-eth-1000.html

You would configure the Ethernet port as a Modbus/TCP Server and configure the RS-485 port as a Modbus RTU Slave. Configuration of the gateway is performed using the ICC Configuration Studio.
https://www.iccdesigns.com/software/40-icc-configuration-studio.html

 

Thanks for the information…!
Can we use moxa Mgate MB3170 as gateway for this

 

Maybe, but you asked for the best gateway.

In the interest of full disclosure, I am one of the product specialists at ICC for the ETH-1000 and one of the engineers that designed it.

 

The ETH-1000 works as described.