Hart pass-through cip message layout details, Pass-through init (service code= 16#4e), Pass-through query (service code= 16#4f) – Rockwell Automation 1756-OF8H ControlLogix HART Analog I/O Modules User Manual

Page 134

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134

Rockwell Automation Publication 1756-UM533C-EN-P - February 2011

Chapter 8

Getting HART Data By Using CIP MSG

HART Pass-through CIP
Message Layout Details

See the following tables for pass-through information.

Pass-through Init (Service Code= 16#4E)

These tables show the request and reply packet structures for the Pass-through
Init service.

Pass-through Query (Service Code= 16#4F)

These tables show the request and reply packet structures for the Pass-through
Query service.

Table 40 - Request Packet

Offset

Field

Data Type

Definition

0

HART Command

USINT

HART Command Number

(1)

(2)

1

HART Data Size

USINT

Number of Data Bytes for Selected HART Command

(1)(2)

2…256

HART Data bytes

As many bytes as in HART Data Size

HART Command Data

(1)

Request Size = 2…257 bytes

(1) See

Appendix C on page 193

for more information.

(2) If this field is displayed as SINT in RSLogix 5000 software, values > 127 appear negative.

Table 41 - Reply Packet

Offset

Field

Data Type

Definition

0

Status

USINT

Command Status
32 = Busy - try again later
33 = Initiated - command started - send Query to get the reply
35 = Dead - Device not online

1

HART Command

USINT

Echo of HART Command

(1)

2

Handle

USINT

Handle Used in Query Operation

(1)

3

Queue Space
Remaining

USINT

Number of Queues Still Available for This Channel

(1)

If status (bit 0) is 35, refer to

Table 44

for the error code description.

Reply Size = 4 bytes

(1) If this field is displayed as SINT in RSLogix 5000 software, values > 127 appear negative.

Table 42 - Request Packet

Offset

Field

Data Type

Definition

0

Handle

USINT

Handle for Query (from Handle Field above)

(1)

Request Size = 1 byte

(1) If this field is displayed as SINT in RSLogix 5000 software, values > 127 appear negative.

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