HART Multiplexer System KFD*-HM*-16
Appendix
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9
Appendix
9.1
Supported commands
The following tables show the HART commands supported by the Multiplexer,
ordered by three groups (see also section 3.2):
•
Universal commands,
•
Common-practice commands and
•
Device specific commands.
The read commands are caracterized by
and the write commands by
.
The Universal and Common-practice commands are described in detail in /1/. In this
section only the functions are explained, not the data structure of the lower layer of
the HART protocol.
9.1.1
Universal commands
Command
Action
Meaning
0
Read unique identifier.
12 Bytes device identifier are given in the response.
1
Read HART variables (process
values).
Commands are only supported for compatibility purposes
and are without any meaning. Used with transmitters (e. g.
SCAN function) they have the following meanings:
1: Read primary variable.
2: Read primary variable as current (in mA) and percent of
range.
3: Read primary variable as current (in mA) and four
(predefined) dynamic variables.
2
3
6
Write polling address.
This command is never accepted and the messages
"Access restricted" or "Busy" will be returned.
11
Read unique identifier associated
with tag.
A response will contain 12 bytes device identifier, if the given
tag complies to the tag of the Multiplexer.
12
Read "Message".
Read the 32 digit message (see also 17).
13
Read tag, description and date.
Read the 8 digit tag, the 16 digit description and the date.
17
Write "Message".
Write the 32 digit message (see also 12).
18
Write tag, description and date.
Write the 8 digit tag, the 16 digit description and the date.
