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.