Interface Settings; 4-20Ma Interface; Full Scale Deflection; Setting Fault Current - Dräger PointGard 2000 Series Gebrauchsanweisung

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Interface settings

13 Interface settings

13.1 4-20mA interface

The current output of the instrument during normal operation
is between 4 and 20 mA and is proportional to the detected
gas concentration.
PointGard 2xx0 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.

13.1.1 Full scale deflection

PointGard 2100 EC-specific:
Some sensors offer an adjustable full scale deflection to limit
the measuring range for the 4-20 mA interface.
The full scale deflection (FSD) sets an endpoint within the
measuring range of the sensor. If the gas concentration
reaches this endpoint, the 4-20mA interface transmits 20mA.
Example: Required range 0 to 500 ppm CO (e.g. part number
6809605 default 300 ppm, range min/max = 50/1000
ppm).Select full scale deflection as 500 ppm. The analog
output will be linear between 4 mA = 0 ppm and 20 mA = 500
ppm.

13.1.2 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].

13.1.3 Information regarding the warning signal

To transmit a warning signal via the analog interface, the
warning signal must be switched on.
Default setting for warning signal:
– Warning current for interval T2 (1 second)
– Measurement current for interval T1 (9 seconds)
Time intervals and the warning current can be changed.
[mA]
20
4
3
T
T
1

13.1.4 Switching the warning signal on or off

1. Select Settings > Communication > Analog interface >
Warning and confirm.
2. Select Enable or Disable and confirm.
28
t
[s]
2

13.1.5 Setting warning interval

1. Select Settings > Communication > Analog interface >
Warning interval and confirm.
2. Set times for warning intervals T1 and T2 and confirm.

13.1.6 Setting warning current

1. Select Settings > Communication > Analog interface >
Warning current and confirm.
2. Set the current and confirm with [OK].

13.1.7 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

13.1.8 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.

13.1.9 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 0.5mA)
and confirm.
3. Set the current and confirm.
 The setting for the Analog offset is displayed.
4. Select Confirm and confirm with [OK].

13.1.10 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 0.5mA)
and confirm.
3. Set the current and confirm.
 The setting for the Analog span is displayed.
4. Select Confirm and confirm with [OK].
Instructions for use
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1,1
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Dräger PointGard 2000 Series
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