TimeoutException with Sim800 module

[HamidMousavi-git]

Hi
I want to test this library with Sim800 module but it raise timeout exception
i test the module with putty and also with below code and every thigs is ok:

`import serial
import time

ser = serial.Serial(port='COM3', baudrate=9600, timeout=3)
ser.write(b"AT\r\n")
time.sleep(1)
ser.write(b'AT+CMGF=1\n\r')
time.sleep(1)
ser.flushInput()
ser.flushOutput()
command = b'AT+CMGL="ALL"\n\r'#gets incoming sms that has not been read -("REC UNREAD","REC READ","STO UNSENT","STO SENT","ALL")
ser.write(command)
time.sleep(1)
print('ser.inWaiting(): {0}'.format(ser.inWaiting()))
print(ser.read_all())
while ser.inWaiting():
print(ser.read_all())
ser.close() `

but when i run identify-modem.py or other examples it raise timeout exception

python.exe c:/Users/Hamid/Desktop/python-gsmmodem-master/tools/identify-modem.py COM3 -b 9600 -d
args: Namespace(port='COM3', baud='9600', pin=None, debug=True, wait=0)
Connecting to GSM modem on COM3...
Traceback (most recent call last):
File "c:\Users\Hamid\Desktop\python-gsmmodem-master\tools\identify-modem.py", line 90, in
main()
File "c:\Users\Hamid\Desktop\python-gsmmodem-master\tools\identify-modem.py", line 51, in main
modem.connect(args.pin, waitingForModemToStartInSeconds=args.wait)
File "C:\Users\Hamid\AppData\Local\Programs\Python\Python310\lib\site-packages\gsmmodem\modem.py", line 211, in connect
self.write('ATZ') # reset configuration
File "C:\Users\Hamid\AppData\Local\Programs\Python\Python310\lib\site-packages\gsmmodem\modem.py", line 464, in write
responseLines = super(GsmModem, self).write(data + writeTerm, waitForResponse=waitForResponse, timeout=timeout, expectedResponseTermSeq=expectedResponseTermSeq)
File "C:\Users\Hamid\AppData\Local\Programs\Python\Python310\lib\site-packages\gsmmodem\serial_comms.py", line 144, in write
raise TimeoutException()
gsmmodem.exceptions.TimeoutException: None

[t-rekttt]

I found out that change dsrdtr and/or rtscts to false in this line will fix it.
Specifically:
dsrdtr = false, rtscts = false: Working
dsrdtr = true, rtscts = false: Working
dsrdtr = false, rtscts = true: Not working