---
title: "readAttributeRmsExtremeOverVoltagePeriodPhaseB(with:)"
framework: matter
role: symbol
role_heading: Instance Method
path: "matter/mtrclusterelectricalmeasurement/readattributermsextremeovervoltageperiodphaseb(with:)"
---

# readAttributeRmsExtremeOverVoltagePeriodPhaseB(with:)

## Declaration

```swift
func readAttributeRmsExtremeOverVoltagePeriodPhaseB(with params: MTRReadParams?) -> [String : Any]?
```