unknown media type

Dear Sir,
Run gurux.dlms.client.example.java with bellow settings.
Modified the GXDLMSSecureClient.java class.......
public GXDLMSSecureClient(final boolean useLogicalNameReferencing) {
this(useLogicalNameReferencing, 32, 1, Authentication.LOW, "************",
InterfaceType.HDLC);
}

output in consol:

GuruxDlmsSample reads data from the DLMS/COSEM device.
GuruxDlmsSample -h [Meter IP Address] -p [Meter Port No] -c 16 -s 1 -r SN
-h host name or IP address.
-p port number or name (Example: 1000).
-S serial port.
-i IEC is a start protocol.
-a Authentication (None, Low, High).
-P Password for authentication.
-c Client address. (Default: 16)
-s Server address. (Default: 1)
-n Server address as serial number.
-r [sn, sn] Short name or Logican Name (default) referencing is used.
-w WRAPPER profile is used. HDLC is default.
-t [Error, Warning, Info, Verbose] Trace messages.
-g "0.0.1.0.0.255:1; 0.0.1.0.0.255:2" Get selected object(s) with given attribute index.
Example:
Read LG device using TCP/IP connection.
GuruxDlmsSample -r SN -c 16 -s 1 -h [Meter IP Address] -p [Meter Port No]
Read LG device using serial port connection.
GuruxDlmsSample -r SN -c 16 -s 1 -sp COM6 -i
Read Indian device using serial port connection.
GuruxDlmsSample -S COM6 -c 16 -s 1 -a Low -P [password]

It's taking media=null;
So kindly suggest me where I will initialize the media ? I have serial com port .
I got the meter data using .net code and GXDLMSDirector with low authentication.

Kindly reply me sir.

Thanks & Regards,
Tanmay Pramanik