MVI56-HART ♦ ControlLogix Platform
Configuring the MVI56-HART Module
HART Multi-drop Master Communication Module
User Manual
ProSoft Technology, Inc.
Page 47 of 171
October 13, 2011
2.3.2 Example of HART Command Function 34
The following example shows how to configure a command function 34 (WRITE
DAMPING VALUE) to write a damping values (seconds) to the HART slave device.
According to the HART specification, this command will write one floating point variables:
Word
High Byte
Low Byte
0
Floating Point Damping Value (Sec)
1
The HART device should also return the floating point value after it processes the
request:
Word
High Byte
Low Byte
0
Floating Point Damping Value (Sec)
1
The HART device also returns an integer status data:
Word
High Byte
Low Byte
1
STATUS WORD
This command will return the following number of words:
Parameter
Data Type
Direction
Number of
Words
Database Address
(this example)
Damping Value Floating Point Written from MVI to slave
2 (4 bytes)
400 (word address)
or 800 (byte
address)
Damping Value Floating Point Read from slave to MVI
2
240 (word address)
Status Word
Integer
Read from slave to MVI
1
290 (word address)
The user can configure the command parameters as described in the following table.
Index
Parameter
Value
Observation
1
Enable
1
The command is sent continuously
2
Float DB
Address
300
The damping value response will be copied to the
internal database starting at word-address 300
(occupies addresses 300 to 301)
3
Poll Interval
0
The command is sent without any delay
4
Word Count
2
The command returns 10 words of floating point
data
5
Swap Code
3
The bytes in each returned floating point word are
swapped
6
Short Address 0
This command is sent to the Hart slave device using
short address 0
7
Function Code 34
The command function 4 (WRITE DAMPING
VALUE) is used in this example
8
Int. DB Address 320
The integer data will copied to the database word-
address 320
9
Word Count
1
The command returns 1 word of integer data
10
Swap Code
3
The bytes in each returned integer data will be
swapped
11
Use Long
1
This command executes using Long Address
