Sensor board with rpi

Greetings all. I’ve got a little Pi based IOT solution that interfaces with pump controllers on modbus & links them to the cloud. Some of the simpler controllers don’t do 3phase electrical current measurement which leaves us looking for a solution independent of the controller. Looks like I’d need 2 sensor cards (only 2 CTs ea?) to do 3 phase? I’m not a big fan of low power local wireless (433MHz or WiFi), is it possible to talk to the sensor cards on modbus or some other serial?