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User Functions
At the end of the Output / Input Points there are three User Functions for the Linearization Ta-
ble. These Functions are here to assist the user with the Linearization Table values.
1. BACK UP Table - Selecting this Function will store all of the values in the Linearization
Table to a Back Up file in the Eprom of the MT5000.
2. RELOAD Table - Selecting this Function will reinstall the values of a Linearization Table
that have been stored in the Back Up file of the MT5000.
3. CLEAR Table - Selecting this Function will completely erase all values from the Lineariza-
tion Table.
These functions will only affect the Linearization Table values. They will not affect any other
settings of the MT5000.
4.6.5. SOR (HART VERSION ONLY)
Signal Out of Range: SOR has two selections – SATURATION = Saturation; ALARM = Alarm. This function prevents
the abrupt mA output change that is common in applications of low dielectric constant fluids in EC chambers. To
take advantage of this programming, the module's Failure Alarm jumper should be set HIGH, and SOR Set to
ALARM.
Description: SATURATION (normal operation) and ALARM selections are described below.
A. SATURATION – (Existing transmitter normal operation with a low D.C. fluid): When the chamber level exceeds
the URV, the output will continue to track the level until the output saturates at 20.56mA. Should the level con-
tinue to increase to the point that the level echo is lost, the next echo that the module immediately recognizes is
the centering disc at the end of the antenna. Since the centering disc echo is being detected through the low DC
fluid, it appears significantly below the actual distance and the output drives to 3.85mA (saturated output) caus-
ing significant control problems. This situation is generally not a problem with a high DC fluid application be-
cause when the transmitter loses its echo, it cannot ―see‖ the centering disc through the fluid and therefore en-
ters the transmitter's ―alarm‖ mode (generally set High @ 21 mA).
B. ALARM – As the level increases as described in SATURATION above, when the level increases such that the
transmitter loses the echo from the real level (output is 20.56 mA), the transmitter is prevented from ―seeing‖ the
centering disc below the engineering units entered in LRM. If the transmitter sees no echo, it will enter its alarm
state (21 mA) as programmed by the jumpers on the face of the module. The transmitter's output now simply
increases from 20.56 mA (out of range saturation – high) to 21 mA (Transmitter Failure Alarm – High), prevent-
ing any control upset. When the level drops and the transmitter re-acquires the true level echo, the transmitter's
output will change from 21 mA (Failure Alarm high) to 20.56 mA (measurement out of range –high), and then
track the level downward to 20 mA (URV) and normal operation.
LRM (only if SOR is set to ALARM) – Low Range Margin – the limiting distance below LRV (4.0 mA
value) at which a valid echo will be recognized. This value is displayed and can be changed only when
ALRM is selected. LRM is a positive value and can be up to 50% of sensor trim span. This value is not
critical and is typically set at 4.0‖ (10cm).
MT5000-0200-1 Rev f (10-2010) DCN0528
BACK UP
Table
LVL XX.XX in
XX.XX mA
RELOAD
Table
LVL XX.XX in
XX.XX mA
CLEAR
Table
LVL XX.XX in
XX.XX mA
31
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