ios - didUpdateNotificationStateForCharacteristic で CBcharacteristics 値を取得できません

Question

正常に接続されている BLE デバイスを使用しています。この場合、文字列「GET DATA」を BLE デバイスに送信すると、デバイスは特定の応答を返すことで応答します。didDiscoverCharacteristicsForService を使用して writeValue ("GET DATA") を実行しています。didUpdateNotificationStateForCharacteristic のデータを期待していますが、毎回応答があります。

 - (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error
{
    if ([service.UUID isEqual:[CBUUID UUIDWithString:@"Some service UUID"]])
    {         
         for (CBCharacteristic *aChar in service.characteristics)
         {
             if ([aChar.UUID isEqual:[CBUUID UUIDWithString:@"Some UUID"]]) 
             {
                 NSString *str = @"GET DATA";
                 NSData *someData = [str dataUsingEncoding:NSUTF8StringEncoding];
                [self.RN2058Peripheral setNotifyValue:YES forCharacteristic:aChar];
                [self.RN2058Peripheral writeValue:someData forCharacteristic:aChar type:CBCharacteristicWriteWithResponse];
             }  
         }
     }
}



- (void)peripheral:(CBPeripheral *)peripheral didUpdateNotificationStateForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error
{
    if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:@"Some UUID"]])
    {
        NSString *value = [[NSString alloc] initWithData:characteristic.value encoding:NSUTF8StringEncoding];
        NSLog(@"Value %@",value);

        NSData *data = characteristic.value;
        NSString *stringFromData = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
        NSLog(@"Data ====== %@", stringFromData);
    }
}