Dräger Polytron 8900 UGLD Instrucciones De Uso página 20

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en Interface settings
2. Select the desired option and confirm.
REGARD SW 2.0
REGARD SW 1.4
11.2 4-20mA interface
The current output of the instrument during normal operation
is between 4 and 20 mA. Between 4.5 and 18 mA the current
changes proportionally to the detected ultrasonic sound
levels. Whereas 4 mA < 55 dB (0 % of measuring range) and
20 mA equals 110 dB (100 % of measuring range).
Alarms are not transmitted via the analog interface. Alarm
thresholds must be set at the control unit.
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 is at 100 %
measuring range which 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 10.
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)
20
Default setting
For REGARD controllers with
SW 1.4
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.
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.
Instructions for use
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Dräger Polytron 8900 UGLD
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