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LS-MC
Issue: 5.0
Date Of Issue: 10/06/2009
© 2009 Sontay Limited. All rights reserved.
Selecting The Output Current Output On Alarm
Condition (continued) Blocking Unwanted Echoes From False Targets
Lo
The current on the two wire loop will drive down to 3.6mA
and remain there until the correct target echo is recovered.
The display will flash "LE" and the last reading.
To change the action from the default action Hold, enter the
menu using, the blue button to show the current action.
Press blue button to enter edit mode. With the display
flashing use green button to display the required action
and then press blue button to select this action and the
display will stop flashing. Press red button to save and
scroll on to the menu that allows setting of the 4mA and
20mA levels against a known target.
Setting the 4 and 20mA Levels Using Actual
Liquid Levels in Tank (S--4 and S-20)
If you have already programmed the 4 and 20mA levels as
above, you do not need to enter this menu. All the program-
ming is now complete and you should press the green but-
ton to move to the final "Lrn" option in the main menu.
If, however, you wish to set the 4 or 20mA level by ranging
the instrument to a known target - perhaps the level in the
vessel at this time - then press the blue button to enter
this menu.
The first option is to set the 4mA level. Ensure the target is
at the desired 4mA level and, with the display reading the
new value, press the blue button . The display will show
the present value for the 4mA setting. Press the blue button
again to edit the 4mA level, and the display will alter-
nately flash “4” with the current level reading.
Press blue button to confirm the correct value for the
4mA level then press red button to save and exit to the
20mA setting menu.
To set the 20mA level, ensure that the target is at the de-
sired 20mA level and, with the display reading the new
value, press the blue button . The display will show the
present value for the 20mA setting. Press the blue button
again to edit the 20mA level, and the display will alternately
flash “20” with the current level reading.
Press blue button to confirm the correct value for the
20mA level then press red button to save and exit to the
"Lrn" menu.
The LS-MC has an easy to use “Lrn” (Learn) routine which
allows the user to teach the instrument up to 2 false echoes
and then ignore them in future operation.
If the application is straight forward and there are no false
echoes, press the green button now to exit the program-
ming menu and return the instrument to normal operation,
showing the level reading on the display.
If, once the LS-MC is in operation, an echo other than the
true liquid surface echo is detected, and an incorrect level
reading is displayed, the instrument can be taught to ignore
this false echo. This routine may be used at any time, either
during or after set-up or should a problem occur later.
Press blue button to enter the Lrn menu. The display will
show “LrnX”, where X is 0,1 or 2 and is the number of false
target echoes already stored. To store a new false echo,
press the blue button for greater than 5s.
Note : If there are already 2 false echoes stored (Lrn2) then
the LS-MC will not allow the user to store another echo until
the memory is cleared. (see below).
The display will now flash the false target position alternat-
ing with "Lrn". After 4s the false target is stored and the
display shows "LrnX". If for any reason this target is not to
be saved then press the blue button and the "Lrn"
sequence may be repeated or aborted. Otherwise, press the
red button to save the false target echo and return to the
main menu.
To store another false target echo, navigate down the main
menu to "Lrn" and repeat the sequence again.
Note: When a false target echo is stored, the LS-MC
effectively sets up a 'window' around the false target and
will ignore any echo from within that window unless the
echo from the liquid surface is larger than that from the
false target.
The user may therefore see no change in the LS-MC output
current whilst the liquid level moves through this window,
which is equivalent to a distance of around 200mm.
To clear the LS-MC of all false echoes stored, simply press
blue button to enter the Lrn menu then with the display
showing "LrnX" press the green button for 10s to com-
pletely clear the memory. The display will now show "Lrn0".
