Users Manual Part 2
Table Of Contents
- Contents
- 1 Preliminary note
- 2 Safety instructions
- 3 Intended use
- 4 Items supplied
- 5 Function
- 6 Mounting
- 7 Electrical connection
- 8 Parameter setting
- 9 Operation
- 10 Troubleshooting
- 10.1 Troubleshooting incorrect level readings
- 10.1.1 Level too high / too low
- 10.1.2 Measured value is stuck
- 10.1.3 Measured value drops when level close to antenna
- 10.1.4 Measured value fluctuates
- 10.1.5 Measured value is occasionally unstable
- 10.1.6 Lagging of measured value during rapid level changes
- 10.1.7 Measured value correct at 0% (4 mA) but incorrect at 100% (20 mA)
- 10.1.8 Incorrect measured value when level is above 50%
- 10.1.9 Measured value drops to zero close to tank bottom
- 10.1.10 Level measurement is lost in an empty tank
- 10.1.11 Alert mode when level close to tank bottom
- 10.1 Troubleshooting incorrect level readings
- 11 Maintenance, repair and disposal
- 12 Factory setting
- 13 Appendix
Electronic level sensor LW2720
29
Parameter Options Explanation Access
FOU2 [On] = analogue output switches to a val-
ue >21mA in alert mode.
Switching output switches ON in alert
mode.
[OFF] = analogue output switches to a
value <3.6mA in alert mode.
Switching output switches OFF in alert
mode.
Response of OUT2 in alert mode.
dAP Setting range: 0...600s Damping of the measured signal (filter).
S.Lvl Setting range: 0...10 m Level to be simulated in simulation mode.
The set value is not part of the data storage. It is
not stored in the master.
S.Tim [60min] fixed setting. Simulation time.
Alert mode delay
time
Setting range: 0...1000s The time delay for transfer to alert mode.
Only effective in case of a fault. Defined state in
the event of a fault (alert mode) (Ò/12)
Detection threshold Setting range: 0...20,000mV
Level detection threshold (Ò Fig. Detection
threshold).
*
)
According to VDMA, the switch-on delay always has an effect on set point1 (e.g. [SSC1 Param.
SP1]), the switch-off delay always on the hysteresis or reset point2 (e.g. [SSC1 Param. SP2])
irrespective of whether the normally open or normally closed function is used.
Reference height:
A
B
C
Fig.14: Reference height
A: device reference point (lower edge/sealing edge of the process connection)
B: reference height (measuring range)
C: zero point (tank bottom or lower end of the measuring range)
The measuring range ends at the zero point (C).
• Levels below zero are not detected; [0.0 m] is provided as process value.
• If the level drops below zero, the unit briefly sends the process value [NoData] and the error
message [No reflection signal].
If this behaviour is not desired:
u Ensure that the level does not fall below the minimum (position C), e.g. by selecting suitable switch
points (or by throttling the outlet).
Or alternatively:
u Enter a tank offset (Ò Fig. Tank offset)
Tank offset:
GB