EtherNet/IP Serial Interface (Class 0x68)

Data is sent and received on the serial port using explicit messaging. The host should send Get_Attribute_Single (0x0E), Set_Attribute_Single (0x10) or vendor-specific service Send_with_Response (0x45) to vendor-specific Object Class 104 (0x68), Instance 1, Attribute 106 (0x6A).

The Set_Attribute_Single and Send_with_Response services include a 16 byte header that specifies parameters for control of the serial interface. However, the Set_Attribute_Single service cannot receive any data in the response so only the Send parameters are valid.

Attribute ID (dec)	Access	Name	Data Type	Description
106	Get/Set/SendResp	Serial Interface	Struct. of:
			UINT	Send length (0-470)
			UINT	Receive length (0-470)
			UINT	Receive timeout [ms]
			USINT	Receive idle timeout (low byte) [ms]
			USINT	Reserved
			USINT	Send flags
			USINT	Receive flags
			USINT	Reserved
			USINT	Frame trailer (Postamble) flags
			USINT [4]	Frame trailer (Postamble) (1-4 bytes)
			USINT [x]	Data

The Get_Attribute_Single service does not supply any data, and so cannot specify any parameters, but will always provide the 16 byte header in the response, along with all the bytes available in the receive queue (maximum 470). The host should insure that adequate space is available for the maximum response data.

The Send_with_Response service is the most flexible, and can supply data in both the command and response. This service is useful for sending a serial command and waiting for a serial response based on a defined protocol.

All UINTs are little-endian, with the least significant byte or USINT sent first, followed by the most significant byte.