In EM6400 series we have various items with varieties of inbuilt features and cost is also dependent based on upon these features.
To check communication compatibility we have two methods: -

1. The RS485 is printed between D1 & D0 for EM6400 model having communication compatibility.

In item code description RS is mentioned

2. In item code description RS is mentioned with RS485 enabled model.

30001994            EM6436 1.0 (Without communication compatible)
30001999            EM6436 1.0 RS (Communication compatible)

Please see the back side images of 30001994 which not communication compatible. Please see the arrow mark where RS485 is printed with communication enabled meter.
 

Released for:Schneider Electric India