www.miinet.com
Moore Industries-International, Inc.
- 119 -
User’s Manual
238-760-00K
May 2019
Functional Safety Dual Input Smart HART® Temperature Transmitter
STZ
SECTION 7
Configuration
The unit can be configured using a HART master, a HART communicator or a PC running an
FDT/DTM program, as described in this manual. Do not attempt to configure the STZ while the
unit is performing its safety function.
After making any configuration changes, the user must validate the operation of the STZ offline
to ensure that the changes work safely, prior to putting it back into operation.
The following considerations and restrictions will apply when using the STZ in a safety
application:
HART mode: Full Access/Read Only/Disable
The STZ provides 3 HART modes: Full Access/Read Only/Disable. This can only be set
using the DTM with MISP cable. It is recommended to operate with HART in Disable or Read
Only mode while the STZ is performing its safety function. This will prevent unauthorized or
unplanned configuration changes during operation.
Input Sensor
The STZ is designed for use with a wide variety of inputs. It is the end user’s responsibility to en-
sure that the chosen sensor is capable of achieving the required loop SIL.
Trimming:
Sensor trimming should be used with extreme care as this facility is allowed
to trim the sensor accuracy by as much as 2% of the trimming point value. It is the user’s
responsibility to ensure that the safety application can tolerate this.
Diagnostics:
The STZ 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).
Broken Wire Detection:
The STZ is provided with the facility to detect check for broken
wiring or a burned out sensor. This broken wire detection must always be enabled (default
setting) and is essential to ensure that dangerous failure of the sensor or signal input is
detected by the STZ and consequently alarmed. If Broken Wire Holdoff Time is set (0-60
seconds) please ensure that the setting does not affect the process safety time.
Input Quality Alarms:
The STZ allows the user to determine how certain types of input
quality issues are handled and how they can affect the Device Variables and their mapped
Dynamic Variables/AO (See Operation and Maintenance section for more details). If these
settings are changed from default values, please ensure that this does not affect the safety
function.
WARNING:
The input quality flags are intended to increase the availability of the system when
using two sensor inputs. However, if SEN1 or SEN2 is directly mapped as the PV and the flags
are set off, a poor accuracy or limited condition will not result in an output fail response. For
SEN1 and/or SEN2, configure a Range Alarm to produce an error or warning when the variable
is outside of its conformance range or upper/lower limit.