How The Module Automatically Collects Data - Allen-Bradley 1719 Ex I/O User Manual

The module collects the PV, SV, TV, and FV data as described in
Table 3 - Dynamic Variable Assignment
HART HART Device Reports PV,
Version SV, TV, FV Assignments in
Command 50
5 N/A
6 No
Yes
7 or later No
Yes
Command 3 does not provide PVStatus, SVStatus, TVStatus, or FVStatus, so
HART devices that indicate Command 3 as shown in
Dynamic Variable Status values reported based on the communication status
with the HART field device. If the Dynamic Variables are being collected
without communication error, the Status value is 16#C0 (2#11000000), which
means good. Otherwise, it is 0, meaning bad.
Some devices don't have four dynamic variables. In this case, they can report a
NaN value to indicate they have no valid value for that parameter.
The dynamic variables do not update as fast as the analog signal. The actual rate
depends on the number of channels configured for HART, the number of pass-
through message commands, the presence of handheld communicators or other
secondary masters, and the response speed of the field device.
Verify that the actual HART update rate is appropriate for your application.
IMPORTANT
Remember that pass-through message traffic, additional status information,
secondary masters, and communication errors can delay the update rate.
Verify that HART data is valid by checking ChxFault, HARTFault, and values such
IMPORTANT
as PVStatus and SVStatus.

How the Module Automatically Collects Data

The 1719 Ex I/O HART analog module automatically sends HART messages to
characterize the HART field device and collect the dynamic variables. It also
collects additional status information when the device indicates it is available.
When the device indicates its configuration has changed, HART messages are
sent to reread the configuration information so that a current copy is cached in
the modules.
The diagram on page 55
response to a new configuration, and cyclic scanning of dynamic variables. Not
shown are periodic checks of the current and reading the additional status
information.
Rockwell Automation Publication 1719-UM001C-EN-E - August 2018
1719 Ex I/O HART Analog I/O Modules
HART Command Used by Device Variable Codes
1719 Module to Collect Used in Command 9 for
PV, SV, TV, FV PV, SV, TV, FV
3 N/A
3 N/A
9 As Reported in Command 50
9 246, 247, 248, 249
As Reported in Command 50
shows the general flow of the start-up characterization,
Chapter 5
Table 3.
Table 3 will have their
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