Spectrex 40/40R - Single IR Flame Detector - Manual (Page 17)

TM 40/40R, Rev (4) November 2010
Principles of Operation 5
1.4.2 Heated Optics
The SharpEye 40/40 Flame Detectors use heated optics. The heater
increases the temperature of the optical surface by 5-8°F (~3-5°C) above
the ambient temperature to improve performance in icing, condensation and
snow conditions.
The heated optics can be set to one of the following:
• Not operated
• On continuously
• Automatic, per temperature change (default): you can define the start
temperature below which the window is heated. (The default is 41°F
(5°C).) This temperature can be defined between 32°F (0°C) to 122°F
(50°C). The heating stops when the temperature is 27°F (15°C) above
the start temperature.
For more information, see Configuring your Detector on page 27.
1.4.3 HART Protocol
The SharpEye40/40 Flame Detectors use the HART protocol.
HART Communication is a bi-directional industrial field communication
protocol used to communicate between intelligent field instruments and host
systems. HART is the global standard for smart process instrumentation and
the majority of smart field devices installed in plants worldwide are HART-
enabled. HART is available in wiring options 2 and 3, see Table 1, page 3.
HART technology is easy to use and very reliable.
Through the HART connection, you are able to perform:
• Detector set-up
• Detector troubleshooting
• Detector health and status
For more details, refer to the HART Manual TM 777030.
1.4.4 RS-485 Modbus
For more advanced communications, the 40/40R detector has an RS 485
Modbus-compatible output that provides data communication from a
network (up to 247 detectors) to a host computer or universal controller for
central monitoring. This feature allows for reduced installation costs, easy
maintenance and local or remote diagnostic tools.