Burkert Type 8620 - Manual (Page 65)

mxCONTROL Type 8620
Page 65
For displaying and data logging purposes there are adjustable upper and lower warning limits and a
separate warning hysteresis WarnHys
.
The alarm and warning limits are configured in the unit of the process value.
The function scope of the alarm and warning function can be configured as follows:
Alarm mode Description
Alarm & Warn Alarm and warning function enabled.
Alarm Only alarm function enabled. Parameters of the warning function are not indicated.
disable Alarm and warning function not enabled. Parameters are not indicated.
If one of the two alarm limits is not required while the alarm function is enabled, this alarm limit is to be
set to a value outside of the accessible process value range.
Example: Conductivity measurement, process value range: 0 - 1000 µS/cm, no alarm necessary
at lower alarm limit -> set lower alarm limit to -1 µS/cm
User Calibration
The user calibration function of the Type 8620 offers the possibility to adopt the input scaling of the
4-20mA sensor signal for user calibration of sensors.
For the User Calibration procedure proceed as stated below:
→ Scroll in main menu to the menu item “Calibration” (via “arrow” keys),
press key “ENTER”.
(the calibration is password protected: for specialist only)
→ Enter “Inputs” , choose an input and press key “ENTER”
(menu entries are only displayed if the input was configured as enabled and
calibration functionality was set to “YES”).
→ Choose the calibration mode :
- 1-point or
- 2-point or
- Manual
and press key “ENTER”
Alarm activation is equipped with a switching hysteresis (AlarmHys) to prevent excessive
switching. The hysteresis has to be parameterized in percent of input range (i.e. the input
range (Scal- … Scal+) corresponds to 100 %).
Functional impairments due to incorrect calibration
The calibration may only be carried out by qualified personnel.
When downloading a configuration file, the user calibration values are at first internally reset to
the default values before they will be overwritten by the values contained in the configuration
file.
After successful user calibration it is therefore recommended to:
- save the just changed configuration file and
- note the user calibration values for future manual input.