Ref: REFLEX/SCANFLEX MANUAL
EDITION 1: JULY ’97 44
3. Check that all transducer extension cables are RG62AU.
4. Check the condition of the transducer face, the aiming, the cable length and
quality and the correct terminations of the extension cable screen. All of these
can cause higher gains to be used.
'LOSS OF ECHO' at long distances from the transducer:-
1. 'LOSS OF ECHO' at long distances is usually due to insufficient gain available
to recover the echo. Check that Pr.65 is set to 100 (maximum gain). At
ranges approaching the maximum specification, poor surface conditions may
prevent the system recovering the echo at all.
2. Poor aiming of the transducer or the quality of the installation may be causing
the system to be unable to identify a true level. Transducer aiming can be
checked by putting the instrument into manual scan (Pr.53) for the relevant
point, and pressing 'TEST' key on the Controller. Carefully move the
transducer until you obtain the correct level reading with the lowest gain
number possible.
3. Check that the value of the empty distance (Pr.4) is sufficient to include the
bottom of the vessel. This is especially important if temperature variations are
experienced and no compensation is applied. The check this set Pr.4 to a
greater value and see if the system recovers. If it does, re-calculate Pr.4
allowing for temperature variations which are 0.17% of measured distance per
deg.C change in temperature.
'LOSS OF ECHO' when empty on a vessel with conical, parabolic or spherical
bottom:-
1. This is a common problem that occurs if the transducer cannot be mounted
over the centre of the vessel, above the lowest point. When the vessel
becomes empty, the pulse from the transducer hits the sloping edge of the
bottom section and the signal is not reflected back to the transducer. Except
by the use of a target plate, this is difficult to solve. It is better to ensure that
the transducer is mounted centrally.
H) Relay 4 l.e.d. on:-
1. The system may be in Manual Scan Mode (Pr.53=1).
Check for a message on the display.
2. Possible power failure on one or more of the system modules.
Check the power supplies and voltage selection (SW4) on each module.
3. Possible communications fault between the Controller and the modules.
Check the external system modules status by pressing '#' key. The number of
boxes displayed is defined by Pr.51 (max. 15), modules 1-8 on the top line,
9-15 on the bottom line. An empty distance box indicates that module is OK.
A blocked-in box indicates a faulty module. To update the box display after
Making corrections, press '#' key. Check the RS485 link and module address
details - refers to Pages 9 and 10. Check that the green l.e.d. is flashing on all
modules.
I) Relay 5 l.e.d. on:-
Used to indicate that the Controller is in programme mode:- This is not a system
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