STANDARD OUTPUT
A 4 to 20 mA current loop corresponding to 0 to 5 LFL-
meters is provided for connection to analog input
devices such as gas controllers, logic controllers, or
distributed control systems (DCS). To convert the mA
reading to LFL-meters, use the following formula:
mA Reading –4
X
5
=
LFL-Meters
16
OPTIONAL RELAYS
The Model OPECL can be furnished with a factory
installed relay output board that provides two
programmable alarm relay outputs and one fault relay
output. All relays are sealed and provide form C
(NO/NC) contacts. The high and low alarm relays are
programmable and can be set for latching or non-
latching operation.
When the high alarm relay is
configured for non-latching operation, the detector
must be connected to an auxiliary system that
provides the latching function
. The low alarm
cannot be set above the high alarm threshold. Alarm
configuration can be done with the HART or MODBUS
interface. The onboard multicolor LED indicates a
LOW alarm condition via a flashing red color, and a
HIGH alarm condition via a steady red color. The
OPECL internal magnetic switch or HART Field
Communicator can be used to reset latched alarms.
A short-duration magnetic switch activation of 1
second will reset latched alarms. Holding the
magnetic switch closed for 2 seconds will start the
calibration sequence. The external calibration line will
not reset latched alarm relays.
When the optional relay output board is specified,
OPECL is certified for EEx d operation.
COMMUNICATION
The standard OPECL system provides an analog 4-20
mA signal output, with HART and RS-485 MODBUS
serial communication from the receiver module.
RECORDING CAPABILITY
Non-volatile memory is provided to save the 10 most
recent calibrations, alarm/fault events, and
minimum/maximum operating temperature history. A
real time clock is provided to record operating service
time and to time stamp events. This information is
accessible using HART and MODBUS communication.
DETECTION RANGE
The standard OPECL model can cover a range of 5 to
60 meters. For extended range applications, a long
range model can be ordered to provide coverage from
60 to 120 meters.
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