HES
User Manual
HART to Ethernet Gateway System
226-710-00A
September 2018
www.miinet.com
[10]
Moore Industries-International, Inc.
two types of HART variables that you can retrieve from HART devices – Dynamic Variables and
Device Variables.
All of the HART field device HART Variables are IEEE 754 Floating Point values and are
retrieved by the HES from the field device by utilizing HART Command 03 or Command 09.
Dynamic Variables consist of the Primary Variable (PV), Secondary Variable (SV), Tertiary
Variable (TV) and Quaternary Variable (QV). These variables can be obtained from the field
device using HART Command 03 or 09.
Device Variables may also be used in more sophisticated or multivariable HART field devices to
provide additional process, diagnostic or status related information. Device Variables are only
available in HART 6 and 7 revision field devices and are read using HART Command 09. Each
field device can define up to 240 Device Variables (HART 7) numbered consecutively from 0 to
239. The Device Variable Codes are unique to each field device and may be defined in the
operation manual or obtained from the manufacturer. In addition, the following Device Variable
Codes are defined in the HART specification (see table 1.1).
Table 1.1. HART Additional Device Variables
DV
Description
242
(Optional) Battery Voltage
243
(Optional) Battery life
244
Percent Range
245
Loop Current
246
Primary Variable (PV)
247
Secondary Variable (SV)
248
Tertiary Variable (TV)
249
Quaternary Variable (QV)
NOTE:
On some HART field devices the Dynamic Variables - PV, SV, TV and QV, can
be assigned and represented as any of the Device Variables.
