WIKA TIF50 Betriebsanleitung Seite 14

6. Commissioning, operation
Freely programmable sensor functionality when 2 sensors have been connected
(dual sensor)
Sensor 1, sensor 2 redundant:
The 4 ... 20 mA output signal delivers the process value of sensor 1. If sensor 1 fails, the
process value of sensor 2 is output (sensor 2 is redundant).
EN
Average value:
The 4 ... 20 mA output signal delivers the average value from sensor 1 and sensor 2. If one
sensor fails, the process value of the working sensor is output.
Minimum value:
The 4 ... 20 mA output signal delivers the lower of the two values from sensor 1 and sensor
2. If one sensor fails, the process value of the working sensor is output.
Maximum value:
The 4 ... 20 mA output signal delivers the higher of the two values from sensor 1 and
sensor 2. If one sensor fails, the process value of the working sensor is output.
Difference:
The 4 ... 20 mA output signal delivers the difference of the two values from sensor 1 and
sensor 2. If one sensor fails, an error signal will be activated.
Configurable monitoring functionality
Monitoring of the measuring range:
If this function is activated, an error is signalled on the current loop (< 3.6 mA) if the
measured value is either below or over the limits of the measuring range.
Configurable monitoring functionality with 2 sensors connected (dual sensors)
The following options are not available in the differential mode!
Redundancy/hot backup:
In the case of a sensor error (sensor-break, wire resistance too high or measured value
outside the measuring range of the sensor) of one of the two sensors, the process value
will be the value from the working sensor only. Once the error is rectified, the process value
will again be based on the two sensors, or on sensor 1.
Ageing control (sensordrift monitoring)
An error signal on the output is activated if the value of the temperature difference between
sensor 1 and sensor 2 is higher than a set value, which can be selected by the user.
This monitoring only generates a signal if two valid sensor values can be determined and
the temperature difference is higher than the selected limit value. (Cannot be selected for
the 'Difference' sensor function, since the output signal already indicates the difference
value).
14 WIKA operating instructions models TIF50, TIF52