Testing Alarms/Relays; Interface Settings - Dräger Polytron 8000 Serie Instructions For Use

en

Interface settings

e. Set the hysteresis mode.
The hysteresis function defines an interval where a
triggered relay maintains its status until the gas
concentration is outside the defined interval. Example:
Alarm threshold is set to 40 ppm and hysteresis to
3 ppm The alarm stays active until the value falls
below 37 ppm. This prevents relays from chattering at
an alarm threshold.
 A confirmation screen shows all settings.
f. Select Confirm and confirm with OK.
The new settings are saved.

12.11 Testing alarms/relays

These functions change the status of a relay and LED for test
purposes (e.g. to check the function of alarm devices
connected to the relay) and the symbol
exiting this function, the status of the relay and LED will
automatically return to their previous status.
1. Select Settings > Instrument > Alarm the desired alarm
condition and confirm.
Set Alarm A1 Simulates pre-alarm
Set alarm A2 Simulates main alarm
Set fault Simulates fault signal
2. Select Enable or Disable and confirm.
If the function is activated, the fault relay is de-energized
and the 4 to 20 mA interface is set to the fault current. The
yellow LED is lit, the symbol for maintenance is shown.
13 Interface settings
For further information regarding the configuration of other
interfaces consult the relevant documents.
Interface
®
HART
®
PROFIBUS PA
TM
Foundation Fieldbus FF
Modbus RTU
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.
®
Polytron 8xx0 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
®
Polytron 8100 EC, 87x0 IR and 8200 CAT LC only
is displayed. After
Document
Technical Manual
®
Polytron 8000 series
9033848 / 9033845
9033782
9033783
9033781
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.
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
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.
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.
t
[s]
2
®
Dräger Polytron 8000 Series