使用react-native-ble-plx，.isReadable用于特征返回false

Question

尝试从GATT服务0x1818的循环功率测量GATT特征（0x2A63）访问数据，尝试读取由Assioma Duo踏板踩踏产生的功率。最初称为

device.monitorCharacteristicForService("00001818-0000-1000-8000-00805F9B34FB", "00002a63-0000-1000-8000-00805f9b34fb", (error, characteristic) => {
            if (error) {
                this.error(error.message)
            return
        }
        this.updateValue(characteristic.uuid, characteristic.value)
        })

但是this.state.value仍然为空。

决定测试该特性是否完全可读。这是相关的代码

import React, { Component } from 'react';
import { BleManager } from 'react-native-ble-plx';
import { StyleSheet, Text, View, Dimensions, Button, TouchableOpacity, TextInput, Alert, Image, Linking, Platform } from 'react-native';

export default class App extends React.Component {
    constructor(){
        super()
        this.manager = new BleManager();
        this.state = {info: "h", values: {}};
    }

    async testChar(device) {
        const characteristics: [Characteristics] = await device.characteristicsForService("00001818-0000-1000-8000-00805F9B34FB");
        for (let k = 0; k<characteristics.length;k++) {
            const char: Characteristics = characteristics[k];
            console.log(`Characteristics for service: ${char.isReadable}`);
        }
    }


    scanAndConnect() {
    this.manager.startDeviceScan(null,
                                 null, (error, device) => {
      this.info("Scanning...")
      console.log(device)

      if (error) {
        this.error(error.message)
        return
      }

      if (device.name === 'ASSIOMA22702U') {
        this.info("Connecting to Assioma")
        this.manager.stopDeviceScan()
        device.connect()
          .then((device) => {
              return this.testChar(device)
          })
      }
    });
  }

登录.isReadable调用-

 LOG  Characteristics for service: false
 LOG  Characteristics for service: true
 LOG  Characteristics for service: false
 LOG  Characteristics for service: true

，特征0x2A63为第一个错误。为什么此特征不可读？