Connecting Power Meters on RS‑485

The power meter must be configured in a daisy chain configuration. Care must be taken to apply a properly placed termination resistor at the end of the daisy chain.

*It is recommended to use shielded twisted pair wire and shield tied to ground.

Why is the EIA485/RS485 connector labelled "+" and "-"? What happened to A and B?

In order to minimize confusion, the power meter is labelled "+" and "-". Typically, "+" is equivalent to B and "-" is equivalent to A.