
PLX51-HART-4I / PLX51-HART-4O
♦
HART Input/Output
Operation
Multidrop Field Devices
User Manual
ProSoft Technology, Inc.
Page 52 of 127
Table 4.3 – Relay HART Message Parameters
Parameter
Value / Description
Message Type
CIP Generic
Service Type
Custom
Service Code
79 Hex (Relay HART Message service)
Class
40F Hex
Instance
Channel value + 1
1 for Channel 0
2 for Channel 1
3 for Channel 2
4 for Channel 3
Attribute
0
Source Element
Tag of type ProsoftHARTRelayMessageRequest
Source Length
48
Destination Element
Tag of type ProsoftHARTRelayMessageResponse
The required Request and Response HART Command structures are defined as
follows:
Table 4.4 – Relay HART Message Request Structure
HART Command Request
Byte
Offset
Data
Type
Description
0
INT
Request Length
2
SINT
Start Character (0x82 for Long Address)
3
SINT
Long Address 0 (0x80 + Manufacturer ID)
4
SINT
Long Address 1 (Device Type Code)
5
SINT
Long Address 2 (Device ID Byte 0)
6
SINT
Long Address 3 (Device ID Byte 1)
7
SINT
Long Address 4 (Device ID Byte 2)
8
SINT
Command Code
9
SINT
Command Data Length (in bytes)
10
SINT[]
Command Data (If required)
Table 4.5 – Relay HART Message Response Structure
HART Command Response
Byte
Offset
Data Type Description
0
INT
Status (See table below)
2
INT
Packet Length
4
SINT
Start Character
5
SINT
Long Address 0
6
SINT
Long Address 1
7
SINT
Long Address 2
8
SINT
Long Address 3
9
SINT
Long Address 4
10
SINT
Command Code (Echoed)
11
SINT
Reply Data Length
12
INT
Status (Same as at byte 0 above).
14
SINT[]
Command Reply Data