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Moore Industries-International, Inc.
- 46 -
User’s Manual
238-760-00K
May 2019
Functional Safety Dual Input Smart HART® Temperature Transmitter
STZ
SECTION 4
Read Additional Device status every 0.5 second if there are any status changes or every
hour if there are no status changes
HART command 48: Read Additional Device Status
Update period: 0.5 seconds;
Maximum update period: 3600 seconds
Trigger Mode: Change
Trigger Level: 1.0
Trigger Units: (250) Not Used
HART Modes
HART communications can be set to Full Access, Read Only and Disable modes.
In Read Only mode, the STZ responds to HART7 commands to access device variables and
diagnostic status but does not allow any changes to be made to the unit configuration. In Disable
mode, all HART messages sent to the unit are ignored and no HART messages are sent from the
unit.
These modes will prevent unauthorized or accidental reconfiguration of the STZ while it’s
performing it’s safety function. HART communications is in Full Access mode by default and the
mode can only be changed using FDT/DTM with the USB communications cable connected to
the STZ. The HART mode cannot be read or changed using HART communication.
Sensor Diagnostics
Sensor Drift Alert using Range Alarms and Sensor Corrosion Detection can also be used for
predictive diagnostics to warn of future problems.
Broken Wire Holdoff Time allows you to add an additional time delay before a sensor broken
wire is reported which provides some noise immunity and prevents false alarms caused by other
factors that may be misinterpreted as Broken Wire.
Please refer to Section 1 for more detailed information on Sensor Diagnostics.
Input Quality Alarms
The STZ also allows the user to determine how certain types of input quality issues are handled
and how they can affect the Device Variables, Dynamic Variables and AO. There are 3 different
quality alarms: Measurement out of Conformance Range, Allow Limited and Allow Dropping. See
Section 6 for more information.