www.miinet.comMoore Industries-International, Inc.
- 61 -
User’s Manual
225-748-00P
August 2024
Programmable RTD, T/C, Ohms, mV and Potentiometer Safety Trip Alarm
STA
TPRG
SECTION 6
Section 6 - Operation and Maintenance
When the STA is used in a SIL rated safety application, please refer to the Safety Instrumented
Systems section of this manual before operating your unit.
Operation
Once calibrated, installed, and supplied with the correct power, the STA begins to operate
immediately. Depending upon environmental conditions, it can be expected to operate
unattended for extended periods of time.
STA Diagnostics & Fault Alarms
The STA has a high level of diagnostic capability to continually monitor itself and its input. This
section outlines these diagnostics and functionality of the alarms. For a full list of diagnostic
messages and corrective actions please refer to Table 6.1.
Internal diagnostics
On power up the unit runs through a thorough diagnostic test (RAM and ROM TEST messages
are displayed), an initialization process (SYS INIT is displayed) and waits the congured amount
set in the Startup Delay Menu before the fault alarm is cleared. If any failure is found during
power up, the fault alarm will not be cleared and an error message will be displayed. Once in
operation, the unit continues diagnostic tests in the background and will set the fault alarm on
any failure.
Note: For STA units with firmware versions 1.5 and earlier, the startup delay cannot be
configured and is set to 0.
All internal diagnostic faults will cause the fault relay to de-energize and remain in a latched
state. Spurious faults that can be caused by external factors such as transients or surges, may
result in a diagnostic failure and trigger the fault alarm. While some faults may be cleared via the
menu system or MR Terminals (if congured), it is recommended that the STA be power cycled
to clear the latched fault alarm. If the error persists, then please record the error message and
contact MII Customer Support for further assistance.
Note: For STA units with firmware versions 1.5 and earlier, the fault alarm has no configuration
options, is always latched and cannot be reset by MR.
Note: The trip alarms and analog output (AO) are independent from the fault alarms and will be
unaected by the fault alarms (however they may be aected by the specic failure in the unit)
Configuration diagnostics
On power up the stored conguration is validated. If it is invalid then the fault alarm will be set.
To clear the alarm, use the menu system, to reset to the factory conguration (FCTRY CONFG
selection in the options menu), then congure as appropriate for the application.
Before saving a new conguration to the unit, it will be checked for validity. If it is invalid, the
fault alarm will be set. Once the conguration is corrected, the fault alarm will be cleared.