Operating Instructions

iTEMP TMT72 System integration
Endress+Hauser 29
There are three different types of command
• Universal commands:
All HART
®
devices support and use universal commands. These are associated with the
following functionalities for example:
– Recognition of HART
®
devices
– Reading digital measured values
• Common practice commands:
Common practice commands offer functions which are supported and can be executed by
many but not all field devices.
• Device-specific commands:
These commands allow access to device-specific functions which are not HART
®
standard. Such commands access individual field device information, among other
things.
Command No. Designation
Universal commands
0, Cmd0 Read unique identifier
1, Cmd001 Read primary variable
2, Cmd002 Read loop current and percent of range
3, Cmd003 Read dynamic variables and loop current
6, Cmd006 Write polling address
7, Cmd007 Read loop configuration
8, Cmd008 Read dynamic variable classifications
9, Cmd009 Read device variables with status
11, Cmd011 Read unique identifier associated with TAG
12, Cmd012 Read message
13, Cmd013 Read TAG, descriptor, date
14, Cmd014 Read primary variable transducer information
15, Cmd015 Read device information
16, Cmd016 Read final assembly number
17, Cmd017 Write message
18, Cmd018 Write TAG, descriptor, date
19, Cmd019 Write final assembly number
20, Cmd020 Read long TAG (32-byte TAG)
21, Cmd021 Read unique identifier associated with long TAG
22, Cmd022 Write long TAG (32-byte TAG)
38, Cmd038 Reset configuration changed flag
48, Cmd048 Read additional device status
Common practice commands
33, Cmd033 Read device variables
34, Cmd034 Write primary variable damping value
35, Cmd035 Write primary variable range values
40, Cmd040 Enter/Exit fixed current mode
42, Cmd042 Perform device reset
44, Cmd044 Write primary variable units
45, Cmd045 Trim loop current zero
46, Cmd046 Trim loop current gain