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OELD Operating Instructions
5 Configuration
5 Configuration
5.1 General
The OELD has several configurable parameters, which are set using a mobile device running the OELD app. Essentially, these are the
threshold for local alarm indication, mA input level settings, Remove RS485 communication settings, behaviour of the green light
and display settings such as full scale range, measurement unit and gas name.
5.1.1 Threshold for Local Alarm Indication
The gas reading at which the the OELD indicates an alarm (flashing red lights) can be set between 5 and 65 % FSD. The default
setting is 20 % FSD.
Note
This setting is local to the OELD and applies only to the red lights in the OELD backlight. Changing the level will have no effect
on alarm levels configured in the sensor, or in the control room.
Note
Guidance for setting alarm levels appropriate for the application can be found in IEC/EN 60079-29-2 and/or other regional and
local publications.
5.1.2 mA Input Level Settings
The sensor transmits a mA output in relation to the measured gas value. Also the mA output is used to provide an indication of the
status of the sensor which can include warning, fault and inhibit. The mA input to the OELD can be configured to match the mA
output profile of the sensor to control the OELD backlight function and show messages on the OELD display. The factory settings
for Searchpoint Optima Plus and Searchline Excel are given in the table below.
Sensor Status
mA Detection Settings
Searchpoint Optima Plus*
Searchline Excel
Fault
0-1 mA
0 mA
Inhibit
2 mA
2 mA
Warning
3 mA
N/A
Beam Block
N/A
2.5 mA
Low Signal
N/A
3 mA
Gas Reading
4-20 mA
4-20 mA
Over-Range
≥ 21 mA
≥ 21 mA
Note
*Searchpoint Optima Plus with HART® requires a minimum of 1 mA flowing in the current loop for HART® communications to
be maintained. It is possible to set the mA level in the Searchpoint Optima Plus for fault to 1 mA, however this may affect the
reliability of the HART® communications.
To ensure correct reporting of the gas detector status (fault, inhibit, warning and over-range), it is essential that the mA input ranges
are chosen to match those of the connected gas detector. Allow for a separation of at least 0.1 mA between each of the ranges.
