5. Introduction
14
The base value and the factor allow for a further scaling of the corrected meas-
ured value of each measuring channel for zero point and slope. The decimal
point position can be set by the exponent. By setting to zero and entering the
nominal value the scaling values can be automatically calculated.
Limit Values and Alarm
Two limit values (1 max and 1 min) can be set for each meas. channel. If a limit
value is exceeded alarm contacts, that can be individually allocated to limit val-
ues, are provided by means of relay output modules. As a standard, the hyste-
resis is set to 10 digits; however, it can also be adjusted between 0 and 99 digits.
Furthermore, limit value exceeding can also be used to start or stop a data log-
ging.
Sensor Locking
All sensor data stored in the EEPROM of the connector can be protected against
undesired access by means of a graded locking function.
5.1.2
Measurement
A total of up to 20 meas. channels are available for 5 transducers, i.e. it is also
possible to evaluate double sensors, individually scaled sensors, or sensors
with function channels. The meas. channels can be successively selected for-
wards or backwards via keypad. By default all measuring points are scanned
continuously at a measuring rate of 10 mops and the data thus obtained is listed
on the display. However, if you want to have the measured values for the se-
lected channel sent to an analog output, it may be an advantage to use semi-
continuous mode instead; the output value will then always be refreshed at half
the measuring rate set - irrespective of the number of measuring points involved.
Measured Values
The measured values of 1 to 20 measuring points can be indicated on the dis-
play in different menus (that can also be configured) in three font sizes, as bar
graph or as line chart. They are automatically acquired with auto zero and self
calibration and can also be arbitrarily corrected and scaled as required. A sensor
breakage condition is, with most sensors, automatically detected.
Analog Output and Scaling
By means of analog start and analog end any measuring point can be scaled so
that the resulting measuring range covers the full range of the bar graph or line
chart or of an analog output (2V, 10V or 20mA). The measured value of any
measuring point as well as a programmed value can be output to the analog
output
Measuring Functions
Special measuring functions are required for some sensors to achieve an opti-
mal data acquisition. The cold junction compensation is available for thermo-
couples, a temperature compensation for dynamic pressure and pH and con-
ductivity probes, and an atmospheric air pressure compensation for humidity
