---
title: "readAttributeRmsVoltageSagPeriodPhaseC(completion:)"
framework: matter
role: symbol
role_heading: Instance Method
path: "matter/mtrbaseclusterelectricalmeasurement/readattributermsvoltagesagperiodphasec(completion:)"
---

# readAttributeRmsVoltageSagPeriodPhaseC(completion:)

## Declaration

```swift
func readAttributeRmsVoltageSagPeriodPhaseC(completion: @escaping @Sendable (NSNumber?, (any Error)?) -> Void)
```

```swift
func readAttributeRmsVoltageSagPeriodPhaseC() async throws -> NSNumber
```