Siemens SIMATIC 6DL1 136-6AA00-0PH1 - HART Data Management

8.4 Tags
8.4.1 Notes on HART variables
Introduction
HART variables, the properties dialog and address assignment are explained below.
HART variables (Page 86)
8.4.2 HART variables
De󹪝nition
Each HART variable consists of a 4-byte real value and one byte of quality code. A maximum of
four HART variables supported by the connected 󹪝eld device are read cyclically for each channel
with enabled HART functionality. The HART variables are read automatically via the HART
command 3 (for 󹪝eld devices with HART Rev. 5 and 6) or via command 9 (for 󹪝eld devices with
HART Rev. 7 or later).
These four HART variables are always stored in the HART variable data record 121 for each
channel and can be read at any time.
HART variable data record (Page 105)
Description
The following HART variables are available:
• PV (Primary Variable)
• SV (Secondary Variable)
• TV (Tertiary Variable)
• QV (Quaternary Variable)
8.4.3 Quality code
De󹪝nition
The quality code describes the process status of the corresponding HART variable.
HART function
8.4 Tags
F-AI 8xI 2-/4-wire HART HA
86 Equipment Manual, 09/2021, A5E50557845-AA