My apologies, this set up on the down stream device is modbus RTU, however, it uses a rj45 connection. We would be using a gateway RTU -> TCP into the PLC/HMI combo.
Here is the long and short of it. We currently get this set up from a supplier. It takes them 8+ weeks to get one out to us. I figured if we can get a scalable program set up, delivery times would decrease considerably. Thus, making for a happier customer.