ProSoft Technology MVI69-HART - Manual (Page 33)

MVI69-HART ♦ CompactLogix Platform Module Configuration
HART Multi-drop Master Communication Module User Manual
ProSoft Technology, Inc. Page 33 of 169
March 29, 2012
2.2.3 [HART PORT x COMMANDS]
The [HART PORT x COMMANDS] sections of the configuration file contain the
user-defined HART command lists for each channel. The commands in these
lists are sent to slave devices attached to the HART channels. The module
supports up to 100 commands per channel.
Command List Overview
The MVI69-HART module uses a command list to interface with HART slave
devices. The commands in the list specify
the slave device to be addressed
the function to be performed (read or write)
the registers in the internal database to be associated with the device data.
There is a separate command list for each HART channel, with up to 100
commands allowed per channel. The command list is processed from top
(Command #0) to bottom (Command #99), then the process is repeated.
A poll interval parameter is associated with each command to specify a minimum
delay time in seconds between the issuance of a command. For example, a poll
interval of 10 executes the command no more frequently than every 10 seconds.
Write commands have a special feature, as they can be set to execute only if the
data in the write command changes. If the register data values in the command
have not changed since the command was last issued, the command will not be
executed. If the data in the command has changed since the command was last
issued, the command will be executed. Use of this feature can lighten the load on
the HART network. In order to implement this feature, set the enable code for the
command to a value of 2.
The module supports all the Universal (page 115) and Common Practice (page
128) commands, as well as device specific commands. A Device Specific
command is supported without any translation of the data.