ProLinx-HART ♦ ProLinx Gateway
Functional Overview
HART Master with Analog I/O
Driver Manual
ProSoft Technology, Inc.
Page 21 of 104
October 13, 2011
2.3.2 HART Command List
The HART Command List specifies the commands to be executed to the HART devices
connected to a channel. A HART command can be seen as an outgoing message to the
HART devices that provides Write Data for a specific command or a response message
that carries process data (Read Data) back to the module. The ProLinx module supports
three kinds of data blocks in the Universal and Common Practice commands. These data
blocks are:
Integers
IEEE 754 Floating Point Numbers (32 bits)
Packed ASCII character strings
The Packed ASCII character strings are unpacked and placed with the integers data
block.
For all commands, it is possible to select where the Write Data comes from; it can be in
the module’s internal database or it can be configured as a fixed data block in the
command.
For response messages from HART devices, it is possible to configure where the
Floating Point Data and Integer Data will be placed in the module’s internal database, but
this is only possible for the Universal and Common Practice commands. In the case of
Device Specific commands, all the Read Data is placed in the Integer data section. See
HART Command Support for a listing of supported HART commands.
Burst Mode
If a slave on a network will be placed in burst mode, its data can be placed in the
module's database. For the command to be burst by slave device, enter a command in
the user command list with the appropriate HART command number. Set the type field to
0 to disable the command. The parameters in the command will be used to store the data
received from the bursting slave. There can only be one slave bursting on the network at
any one time. This mode can be used for faster update of data from a slave.
2.3.3 Auto-Polling
This feature is enabled by setting the AUTO-POLL CODE (in the configuration file) to a
value of P (point-to-point). If the value N is entered for the parameter, the auto-poll
feature is disabled. When the feature is disabled, the channel will only execute the
commands enabled in the user command list. When the auto-polling mode is enabled,
the module will automatically acquire data from the HART instruments attached to a
channel without the use of user commands. If user commands are present and enabled
when the feature is enabled, they will also be executed independent of auto-polling.
