SCHC Network Interface

The content of Acklio FullSDK can be described in its simplistic view as an adaptation layer with the SCHC mechanisms, and a set of interfaces: the Management API, the Datagram API, the Network API and the L2A interface.
Refer to the diagram of layers and interfaces for a better understanding.

The "UDP Client" and "DLMS using Gurux" Demo examples both use the following AT commands in their communication sequences.

About the Error Messages

Error messages of the SCHC interfaces use the following format: AT_ERROR,<layer_id>,<status> where:

• The layer ID of the Network API is 3
• The status is the numeric value returned by the library and listed in the header file 'fullsdknet.h'.

For example, the error message AT_Error,3,6 means that the session has been aborted by the sender (error 6) at the level of the network interface (layer 3).

Error codes 2, 4, 8 and 9 are not in the table because they are not returned by the FullSDK library.

Send Raw Data

What	Detail
Command	AT+SCHC=SENDB,<ip_data>
Parameter	<ip_data> - The IPv4/v6 packet to be sent, as an ASCII string containing an hexadecimal value
Result codes	OK
	AT_PARAM_ERROR
	AT_ERROR,3,<status>
	+SENDOK
	+SENDFAIL,<status>,<error>

Transmissions

The OK result code or an error is returned immediately. If OK was returned, a transmission is attempted.

• If the transmission succeeds, +SENDOK and the associated socket ID are returned at the end of the transmission.
• If the transmission fails, +SENDFAIL, a status and an error are returned at the end of the transmission.

The status that can be returned after a transmission failure the following:

Numeric value	Error code	Comment
1	NET_ERROR	Internal error
5	NET_L2_ERR	Error from L2 layer
6	NET_SEND_ABORT_ERR	Session aborted by the sender
7	NET_RECV_ABORT_ERR	Session aborted by the receiver

Error Messages

The errors depend on layer 2.

AT_ERROR,3,<status> reports a network layer error with the following possible values:

Numeric value	Error code	Comment
3	NET_BUFFER_ERR	Buffer error
5	NET_L2_ERR	Not joined yet
10	NET_TPL_PARAMS_ERR	Template parameters are not completely configured
11	NET_BUSY_ERR	Layer is busy, request is ignored

Reception of Data from a Remote Application

What	Detail
Command	—
Parameters	—
Result codes	+RECVOK,<binary_data>

Received data is an ASCII string containing an hexadecimal value.