Configuring EtherNet/IP Explicit Messaging Using DATA

Configuring the Data_to_Send Parameter

The Data_to_Send parameter varies in size. It consists of contiguous registers that include—in sequence—both the message type and the CIP request:

Variable	Byte Offset	Data Type	Description	Value
DataToSend[0]	0	Bytes	Message type: High byte = size of the request in words: 16#03 hex (3 decimal) Low byte = EtherNet/IP service code: 16#4B (75 decimal)	16#034B
DataToSend[1]	2	Bytes	CIP request class information - Class Segment: High byte = 16#00 hex (0 decimal) Low byte = 16#21 (33 decimal)	16#0021
DataToSend[2]	4	Bytes	CIP request class information - class: High byte = 16#04 hex (4 decimal) Low byte = 16#10 (16 decimal)	16#0410
DataToSend[3]	6	Bytes	CIP request instance information: High byte = instance: 16#01 (1 decimal) Low byte = instance segment: 16#24 (36 decimal)	16#0124
DataToSend[4...n]	8	Bytes	HART request (see below)	–

The HART request consists of the following fields:

Byte Offset	Field	Data Type	Description
8	Delimiter	Byte	Indicates the position of the byte count and frame type.
9 or 9...13	Address	Byte or bytes	Short address or long address.
10 or 14	Command	Bytes	CIP request class information - class: High byte = 16#04 hex (4 decimal) Low byte = 16#10 (16 decimal)
11 or 15	Byte Count	Byte	Represents the number of data bytes in this request.
12...n or 16...n	Data	Byte array1	(Optional) Application layer data.
1. Each array entry presents 2 bytes of data in little endian format, where the least significant byte is stored in the smallest memory address.

Refer to Token-Passing Data Link Layer Specification, Universal Command Specification and Arcom Multiplexer Specification.