www.miinet.com
Moore Industries-International, Inc.
- 113 -
User’s Manual
238-741-00K
May 2019
Programmable Smart HART Temperature Transmitter
THZ
3
/ TDZ
3
SECTION 6
Section 6 - Operation and Maintenance
Operation
Once calibrated, installed, and supplied with the correct power, the TDZ
3
and THZ
3
begins to
operate immediately. Depending upon environmental conditions, it can be expected to operate
unattended for extended periods of time.
THZ
3
/TDZ
3
Diagnostics
The THZ
3
/TDZ
3
has a high level of diagnostic capability to continually monitor itself and its
inputs. Whenever the unit diagnoses a failure which compromises the unit operation it will enter
failure mode ie.
Set analog output (AO) to fail mode
Send error message to display (TDZ
3
)
Send error message to the HART Handheld/DTM
Set device malfunction status bit in HART and set the relevant HART bits in additional status
The unit will enter failure mode when one of the following occurs:
A device diagnostic error (hardware, software, data, communications)
The Device Variable which is mapped to the PV is marked as BAD
There is a Range Alarm error
There is a configuration error in any Device Variable which has been assigned/ mapped to
HART variables, burst messages or TDZ
3
display
The following provides an overview of the different types of diagnostics. For a full list of status
and diagnostic messages please refer to Status Messages and HART Registers.
Internal diagnostics:
On power up the unit runs through a thorough diagnostic test (RAM,
ROM, CPU etc.) and an initialization process (SYS INIT is displayed on the TDZ
3
). If any errors
are found, the unit will enter failure mode. Once in operation, the unit continues diagnostic tests
in the background.
Configuration diagnostics:
On power up the stored configuration is validated. If it is invalid,
the unit will enter failure mode. To clear the failure, reset to the factory default configuration, then
configure as appropriate for the application. If the configuration is changed, the unit will check
before running and enter failure mode if it is invalid.
Input diagnostics
: The THZ
3
/TDZ
3
has extensive hardware diagnostics of sensor input(s) to
detect broken wire, saturation, out of conformance range and linearization errors. In addition, the
unit can be configured to detect sensor corrosion, sensor drift or in/out of range conditions (see
Section 1, Sensor Diagnostics section for more information).
Every Device & Dynamic Variable in the THZ
3
/TDZ
3
has a quality stamp, per the HART standard.
(See section 1, Tables 1.1 & 1.2 for a list of Device Variables)
