Specifications

ProLinx Communication Gateways, Inc. 14
HART Master Protocol Drive Manual
August 17, 2004
1.2.3 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. Look
at Appendix A for all the supported HART commands.
Write
Data
Floating
Point Data
Integer
Data
HEADER WRITE DATA
HEADER READ DATA