Siemens SIMATIC ET 200SP Manual page 37

When HART mode is enabled, the AI-DI 16/DQ16x24VDC HART HA sends HART commands
to the connected field devices on its own. For each channel, commands are always sent time
about with any pending external HART commands that are received over the command
interface of the module, see HART command interface (Page 79).
Commissioning a HART field device
Only HART field devices that are set to the short frame address 0 can be operated. If a HART
field device with a different short frame address is connected or a connected field device is
reconfigured to a short frame address other than 0 during operation, the module starts a scan
of all possible short frame addresses at the next re-establishment of HART communication
(command 0 with short frame addresses 1...63). As soon as the connected field device
responds, it is converted to the short frame address 0 (HART command 6) by the module.
During the scan, the module reports a HART communication error.
HART commands
The assignable properties of the HART field devices (HART parameters) can be set with HART
commands and read by means of HART replies. The HART commands and their parameters
are divided into three groups with the following properties:
● Universal
● Common practice
● Device-specific
Universal commands must be supported by all manufacturers of HART field devices and
common practice commands should be supported. There are also device-specific commands
that apply only to the particular field device.
Examples of HART commands
The following two tables show examples of HART commands:
Table 6-1
Command
0
11
1
2
3
13, 18
Input/output module AI-DI 16/DQ16x24VDC HART HA (6DL1133-6EW00-0PH1)
Manual, 05/2017, A5E39294170-AA
Examples of universal commands
Function
Read manufacturer and device type - field devices can only be addressed by
their short frame address with command 0
Reads manufacturer and device type
Reads primary variable and unit
Reads current and percentage of range, digitally as floating-point number
(IEEE 754)
Read up to four predefined dynamic variables (primary variable, secondary var‐
iable, etc.)
Reads or writes process tag name ("tag"), description and date (dates are also
sent)
HART function
6.1 How HART works
37