Dräger Polytron 8900 UGLD Instructions For Use Manual page 21

The instrument uses different current values to indicate
various modes of operation. The factory default settings are
user adjustable for application specific requirements. This
follows the NAMUR recommendation NE43.
11.2.1 Full scale deflection
The ultrasonic sensor full scale deflection represents about
110 dB.
WARNING
Sensor malfunction
The default full scale deflection must not be changed.
► Do not change the full scale deflection
► If the full scale deflection was changed by accident within
the menu sensor settings, reset the instrument to default
settings
11.2.2 Settings at the control unit
Alarm thresholds and alarm delays must be set in the control
unit. For further information see: "Alarm threshold", page 9.
11.2.3 Setting fault current
This function defines the current for the fault signal.
1. Select Settings > Communication > Analog interface
>Fault current and confirm.
2. Select the line for editing the current and confirm.
3. Set the current and confirm.
 The setting for the Fault current is displayed.
4. Select Confirm and confirm with [OK].
11.2.4 Information regarding the warning signal
To transmit a warning signal via the analog interface, the
warning signal must be switched on.
The warning signal alternates between the warning current
and the measurement current.
– Warning current (interval T2)
– Measurement current (interval T1-T2)
Time intervals and the warning current are configurable.
[mA]
20
4
3
T
T
1
11.2.5 Switching the warning signal on or off
1. Select Settings > Communication > Analog interface >
Warning and confirm.
2. Select Enable or Disable and confirm.
11.2.6 Setting warning interval
1. Select Settings > Communication > Analog interface >
Warning interval and confirm.
2. Set times for warning intervals T1 and T2 and confirm.
Instructions for use |
Dräger Polytron
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11.2.7 Setting warning current
1. Select Settings > Communication > Analog interface >
Warning current and confirm.
2. Set the current and confirm with [OK].
11.2.8 Setting maintenance signal
1. Select Settings > Communication > Analog interface >
Maint. signal and confirm.
2. Set the signal type and confirm.
static A constant current that can be configured.
dynamic A square wave signal with the following
characteristics:
[mA]
5
3
11.2.9 Setting static maintenance current
The maintenance current can only be set if the maintenance
signal has been set to static.
1. Select Settings > Communication > Analog interface
>Maint. current and confirm.
2. Set the current and confirm.
11.2.10 Setting analog offset
This function adds an offset to the analog output at 4 mA. The
offset adjusts the current at 4 mA without affecting the 20 mA
set point.
1. Select Settings > Communication > Analog interface
>Analog offset and confirm.
2. Select the line for editing the offset (range: -0.5 to 0.5 mA,
SIL: -0.1 to 0.1) and confirm.
3. Set the current and confirm.
 The setting for the Analog offset is displayed.
4. Select Confirm and confirm with [OK].
11.2.11 Setting analog span
This function adjusts the analog output at 20 mA without
affecting the 4 mA set point.
1. Select Settings > Communication > Analog interface >
Analog span and confirm.
2. Select the line for editing the offset (range: -0.5 to 0.5 mA,
SIL: -0.1 to 0.1) and confirm.
3. Set the current and confirm.
 The setting for the Analog span is displayed.
4. Select Confirm and confirm with [OK].
11.2.12 Testing the analog interface
These functions change the current of the analog interface for
test purposes (e.g. to check the programming of the control
unit). It might be necessary to inhibit the alarms at the control
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Interface settings
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