I am using a pymodbus library to fetch data through modbus protocol. I am using a MOXA Nport 5150 RS485 to Ethernet converter for fetching data through Real COM Mode in Windows Server 2022. For a particular COM port, the data fetching is interrupted for an unpredictable amount of time and throws PermissionError(13, 'Access is denied.') and resumes the data fetching on its own. I made many attempts to resolve this error but to no avail. The version of python I am using is 3.13.0. I even tried catching the error and restarting the python script but an error is thrown which says 'Port is not accessible'. I even tried looking up for the Port in Process Explorer but does not return any results. Can some one please help in resolving this error

I tried the following code for restarting the python script whenever there is a permission error or serial exception:

def restart_program():
    print(" Restarting program ")
    python = r"C:\Program Files\Python313\python.exe"
    subprocess.run([python] + sys.argv)
    sys.exit()

I even checked whether the port is open before starting fetching of data using the below:

port = serial.Serial(port_name,9600,timeout = 1)
        if (port.isOpen() == True):

# data fetch code 

I even installed Windows Process Explorer to see whether any other process is using the COM port but did not find any result

Even the COM port is not available when I tied executing the following command in CMD prompt:

mode COM16

I am unable to find any solution. Can some one please help.