Servomex SERVOTOUGH LaserExact 2950, Operator'S Manual

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SERVOTOUGH LaserExact Monitor, Operator Manual 02950001A_1
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HAPTER
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The measuring mode is defined by input through digital communication (e.g. with
service program see Section 4.2),
a) In normal mode the measured gas concentration is periodically 1) printed on the
LCD, 2) output to the 4-20 mA current loop (PLC) (optional), and 3) output to the
optical fibre cable (optional). Measurements can also be polled through serial cable
(RS232) with the service program, or through an Ethernet cable (optional). The
measured gas concentration is updated every 1-5 seconds depending on factory
settings which are optimised for the application. If the instrument can measure two
gases the LCD might look as follows:
Tr 100 % 6.1a1
CO 21.32 %
CO2 32.64 %
The LCD shows the measured average gas concentration(s) in the chosen unit and
the laser beam transmission, which indicates how much light hits the detector relative
to the maximum value (calibrated by the factory).
In case of a warning, the instrument continues to measure the gas concentration as
usual while displaying the message in the bottom line. In case of an error, the LCD
shows <I
NSTR
. ERROR> instead of the concentration, and displays the message in
the bottom line. If the optional auxiliary board is installed a warning causes the
WARNING relay to deactivate (i.e. open), but it does not affect the PLC output. An
error condition causes both the WARNING and ERROR relays to deactivate, and the
PLC output is optionally set to 2 mA (ref. Section 6.8). An explanation of LCD
messages is given in Section 5.4.
b) and c)
Zero and span check functionality is not applicable for this analyser.
d) In maintenance mode the instrument will continue to measure as normal but relay
3 will indicate a maintenance situation (assuming that relay 3 is configured for
maintenance, see Sections 6.8 and 6.9 for details). This mode is mainly required for
emission monitoring applications regulated by authorities.
3. Fault mode is entered when the instrument has detected a severe failure (e.g.
overheating), which might permanently damage the instrument. In this case the
instrument stops measuring the gas concentration and most instrument functions are
turned off. The WARNING and ERROR relays are deactivated (opened), the GAS
ALARM relay is activated and the PLC output is optionally set to 2 mA (ref. Section
6.8). This operating mode is indicated on the LCD with <I
NSTRUMENT
O
FF
>, no gas
concentration is displayed, and the bottom line of the display indicates the nature of