Error Domain=CBATTErrorDomain Code=2 "Reading is not permitted." UserInfo={NSLocalizedDescription=Reading is not permitted.}

I am developing app which manage BLE device. I am trying to write data in didDiscoverCharacteristicsFor method like below.

func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
        if let characteristics = service.characteristics {
                    for characteristic in characteristics {
                        if characteristic.uuid == CBUUID(string: Common.PinUUID) {
            var varInt = 0
            let data = Data.init(bytes: &varInt, count: 1);
            peripheral.writeValue(data, for: characteristic, type: .withResponse)
                        }
        }
    }

When I try to write data on characteristic then I got error like below.

<CBCharacteristic: 0x283b213e0, UUID = 47E9EE30-47E9-11E4-8939-164230D1DF67, properties = 0x8, value = (null), notifying = NO> - Optional("Writing is not permitted.")

My characteristic is Write only type. I don't know why it shows error like this.

Also when I try to read data then I call like below.

  if characteristic.uuid == CBUUID(string: Common.TemperatureDataUUID) {
            print(characteristic)
            peripheral.readValue(for: characteristic)
   }

I got error like below,

<CBCharacteristic: 0x283e77300, UUID = 47E9EE2B-47E9-11E4-8939-164230D1DF67, properties = 0xA, value = (null), notifying = NO> - Optional("Reading is not permitted.")

How to solve it not finding any solution? Please help.

from Error Domain=CBATTErrorDomain Code=2 "Reading is not permitted." UserInfo={NSLocalizedDescription=Reading is not permitted.}