FCI ST100A Series, Installation, Operation And Maintenance Manual

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OPERATION ST100A Series Flow Meter
54 Fluid Components International LLC
HART Operation
HART (Highway Addressable Remote Transducer) is a communication protocol that superimposes a low level digital data signal on a 4-20 mA
current loop. The primary function of the instrument’s HART interface is to present process data via process data commands 1, 3 and 9.
The ST100A Series does not implement the HART Burst mode. A HART master that supports HART 7.0 and higher is required. If using a
HART communicator, a unit that supports HART 7.0 or higher is required (i.e. Emerson 475 Communicator). Connect the installation
(factory/plant) HART wiring to the instrument as described in HART Connections , page 27 .
Process Data Operation
The ST100A Series implements HART 7.0 while maintaining compatibility with earlier versions of the HART protocol. However, HART
commands 1 and 3 have been simplified to only report the primary variable Flow. Use command 9 to access the full suite of available
dynamic variables including temperature, totalizer, and others.
ST100A Series HART Process Data Organization
This section describes how the instrument process data is organized under the HART command 9. For details on command 9 see the
HART Specification “Universal Commands Specification” HCF_SPEC-127, Revision 7.1 and the command 9 description on page 61 .
ST100A Series Process Variable Slots
Table 10 below lists the instrument’s process variables that are read by HART command 9, with each process variable assigned a slot number.
Not all the variables described in this section are available in all configurations of the flow meter. For example, the Flow Totalizer may be
turned on or off.
The process variables include 3 flow classes or types of which only one class of flow is active at a time.
Table 10 – ST100A Series HART Process Variables
Slot # Process Variable
HART Variable Code
Description
Device Variable
Code
Device Variable
Classification
0 Volumetric Flow
1
Primary Variable 0 66
1 Volume (Totalizer) Secondary Variable 1 68
2 Mass Flow
1
Primary Variable 2 72
3 Mass (Totalizer) Secondary Variable 3 71
4 Velocity Flow
1
Primary Variable 4 67
5 Temperature Tertiary Variable 5 64
6 Pressure Quaternary Variable 6 65
Note: 1. Only one flow class active at a time.
Primary Variable Classifications
The instrument can provide flow data in unit types that span several HART classifications. Commands 50 and 51 are used to read and set,
respectively, which flow variable will be mapped to the primary variable. The PV device variable classification can only be one of the following:
● 0: Volumetric Flow
● 2: Mass Flow
● 4: Velocity Flow
Since only PV is used in this manner, command 50 returns 250 for SV, TV, and QV. The setting of the device variable classification determines
which class of flow-related variables is valid, and therefore displayed as implemented when variable slots are read by command 9.
Device Description Files
A Device Description (DD) file lets the HART handheld or host software application fully configure any HART device for which it has a DD
installed. The ST80/ST80L DD files are available for download (pending) from the FieldComm Group website:
https://fieldcommgroup.org/registered-products/
Search by Manufacturer (Fluid Components International LLC) to find the instrument’s files under the product name: FCI ST80/ST100A
Series. The posted DD files are contained in a zip archive with FCI’s manufacturer ID and product device type hex values embedded in the
filename (e.g., hart.0000a6.a677.zip).