IFM Electronic LR2759 User manual

Operating instructions
Electronic level sensor
LR2759
UK
80257883/ 01 02 / 2018

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Contents
1 Preliminary note...................................................................................................5
1.1 Symbols used ...............................................................................................5
2 Safety instructions ...............................................................................................5
3 Items supplied......................................................................................................6
4 Getting started .....................................................................................................6
5 Functions and features ........................................................................................6
5.1 Applications ...................................................................................................7
5.1.1 Restriction of the application area ........................................................7
6 Function...............................................................................................................8
6.1 Measuring principle .......................................................................................8
6.2 Outputs ..........................................................................................................8
6.3 Other features of the unit...............................................................................9
6.3.1 Display functions ..................................................................................9
6.3.2 Analogue function ................................................................................9
6.3.3 Switching functions............................................................................. 11
6.3.4 Damping function................................................................................12
6.3.5 Probes for different tank heights.........................................................12
6.3.6 Defined state in case of a fault ...........................................................12
6.3.7 IO-Link ................................................................................................13
6.3.8 Simulation functions ...........................................................................13
7 Installation..........................................................................................................13
7.1 Installation location / environment ...............................................................13
7.1.1 Minimum distances and connection piece diameter ..........................13
7.1.2 Installation in pipes .............................................................................14
7.1.3 Applications with viscous and fast flowing media ...............................15
7.1.4 Fill openings .......................................................................................15
7.1.5 Heavy soiling ......................................................................................16
7.1.6 Heavy foam build-up and turbulence..................................................16
7.1.7 Notes on tank adjustment...................................................................17
7.2 Probe installation .........................................................................................18
7.2.1 Attaching the probe.............................................................................18
7.3 Probe length ................................................................................................19
7.3.1 Shorten the probe ..............................................................................19

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7.3.2 Determine probe length ......................................................................20
7.4 Installation of the unit in the tank .................................................................20
7.4.1 Installation in open metal tanks ..........................................................21
7.4.2 Installation in plastic tanks..................................................................22
7.4.3 Note on the use according to EHEDG................................................23
7.4.4 Notes on the use according to 3-A .....................................................23
8 Electrical connection..........................................................................................24
9 Operating and display elements ........................................................................25
10 Menu................................................................................................................26
10.1 Menu structure...........................................................................................26
10.2 Explanation of the menu............................................................................28
10.2.1 Main menu........................................................................................28
10.2.2 Level EF (extended functions)..........................................................28
10.2.3 Level CFG (configuration) ................................................................29
10.2.4 EN level (environment) .....................................................................29
10.2.5 Level SIM (simulation) ......................................................................29
11 Parameter setting.............................................................................................30
11.1 Parameter setting in general......................................................................30
11.2 Basic settings (set-up) ...............................................................................32
11.2.1 Enter probe length ............................................................................32
11.2.2 Carry out tank adjustment.................................................................32
11.3 Configure display (optional) .......................................................................33
11.4 Set output signals ......................................................................................33
11.4.1 Set output function for OUT 1 ...........................................................33
11.4.2 Set switching limits (hysteresis function) ..........................................33
11.4.3 Set switching limits (window function) ..............................................34
11.4.4 Set switch-on delay for switching outputs.........................................34
11.4.5 Set switch-off delay for switching outputs.........................................34
11.4.6 Set output function for OUT2 ............................................................34
11.4.7 Scale analogue signal.......................................................................35
11.4.8 Set output logic for switching outputs ...............................................35
11.4.9 Set response of the outputs in case of a fault...................................35
11.4.10 Set damping for the measured signal .............................................35
11.4.11 Set delay time in case of a fault ......................................................35
11.5 Reset all parameters to factory setting ......................................................35
11.6 Change basic settings................................................................................36

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11.6.1 Re-enter probe length.......................................................................36
11.6.2 Set to another medium .....................................................................36
11.7 Simulation ..................................................................................................36
11.7.1 Set simulation value..........................................................................36
11.7.2 Set simulation duration .....................................................................37
11.7.3 Switch simulation on / off ..................................................................37
12 Operation.........................................................................................................37
12.1 Operation with single probe.......................................................................37
12.2 Operation with a bypass or still pipe .........................................................38
12.3 Function check ..........................................................................................38
12.4 Operation indication...................................................................................38
12.5 Read the set parameters ...........................................................................39
12.6 Change between length display and percentage ......................................39
12.7 Error indications.........................................................................................39
12.8 Output response in different operating states............................................40
13 Technical data..................................................................................................41
14 Maintenance / Transport..................................................................................42
14.1 Cleaning and maintenance when used in 3-A applications .......................42
14.2 Transport ...................................................................................................43
15 Factory setting .................................................................................................44
16 Notes on parameter setting via IO-Link ...........................................................44
16.1 Application example...................................................................................45
16.2 Unit locking / data storage (as from IO-Link V1.1).....................................46

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1 Preliminary note
1.1 Symbols used
►Instructions
> Reaction, result
[…] Designation of keys, buttons or indications
→Cross-reference
Important note
Non-compliance may result in malfunction or interference.
Information
Supplementary note.
2 Safety instructions
• Read this document before setting up the product and keep it during the entire
service life.
• The product must be suitable for the corresponding applications and
environmental conditions without any restrictions.
• Only use the product for its intended purpose (→ Functions and features).
• Only use the product for permissible media (→ Technical data sheet).
• If the operating instructions or the technical data are not adhered to, personal
injury and/or damage to property may occur.
• The manufacturer assumes no liability or warranty for any consequences
caused by tampering with the product or incorrect use by the operator.
• Installation, electrical connection, set-up, operation and maintenance of the
product must be carried out by qualified personnel authorised by the machine
operator.
• Protect units and cables against damage.

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3 Items supplied
• 1 LR2759 level sensor
• 1 operating instructions
In addition, the following is necessary for installation and operation:
• 1 probe (→ Accessories)
• Mounting material (if necessary, a launching plate (→ 12.1), → Accessories)
►In the event of incomplete or damaged items supplied please contact ifm
electronic.
►Only use accessories from ifm electronic.
Accessories: www.ifm.com
The optimum function is not ensured when using components from other
manufacturers.
4 Getting started
For the most frequent applications the quick set-up described below is possible.
The quick set-up does not replace observance of the other chapters.
►Install the unit correctly:
Installation distances (→ 7.1), Electrical connection (→ 8).
►Set probe length (→ 11.2).
> The unit is ready for operation.
Without changes = factory settings active (→ 15).
Change of the factory settings (→ 11).
►Optional: Carry out tank adjustment (→ 11.2.2).
►If necessary, make more settings for adaptation to the application
(→ 11.3) and (→ 11.4).
►Check whether the unit operates correctly.
5 Functions and features
The unit continuously detects the level in tanks.

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5.1 Applications
• Food and hygienic areas.
• Applications with increased requirements for protection rating and resistance
(→ Technical data sheet).
The unit complies with the standard EN 61000-6-4 and is a class A product. The
unit may cause radio interference in domestic areas. If interference occurs, the
user must take appropriate actions.
The microwave energy radiated by the unit is much below that of mobile
phones.
According to the current state of science the operation of the unit can be
classified to be harmless to human health.
5.1.1 Restriction of the application area
Incorrect measurements may be caused by the following media:
- Highly absorbing surfaces (e.g. foam).
- Intensely bubbling surfaces.
- Media which are very inhomogeneous, separate from each other thus
forming separation layers (e.g. oil layer on water).
►Check the function by performing an application test.
►Installation in a steady area (→ 7.1).
> In case of signal loss, the unit displays [SEnS] and switches the
outputs to a defined state (→ 12.8).
• The unit is not suitable for bulk materials (e.g. plastic granulates) and media
with a very low dielectric constant, e.g. oils.
• The unit is not suitable for applications where the probe is subjected to
permanent and high mechanical stress (e.g. fast moving viscous media or fast
flowing media).
• Use preferably in metal tanks. When used in plastic tanks, deterioration caused
by electromagnetic interference may occur (noise immunity to EN61000-6-2).
Refer to: (→ 7.4.2).

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6 Function
6.1 Measuring principle
Fig. 6-1 Fig. 6-2
D
The unit operates on the principle of guided wave radar. It measures the level
using electromagnetic pulses in the nanosecond range.
The pulses are transmitted by the sensor head and guided along the probe (Fig.
6-1). When they hit the medium to be detected they are reflected and guided back
to the sensor (Fig. 6-2). The time between transmitting and receiving the pulse
directly relates to the travelled distance (D) and the current level. The reference for
distance measurement is the lower edge of the process connection.
6.2 Outputs
The unit generates output signals according to the parameter setting. 2 outputs
are available. They can be set separately.
OUT1 switching signal for level limit / IO-Link (→ 6.3.7)
OUT2 • analogue signal proportional to the level 4...20 mA / 20...4 mA
or
• switching signal for level limit

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6.3 Other features of the unit
• Hygienic approvals / conformities (→ Technical data sheet)
• For CIP / SIP applications (→ Technical data sheet)
• Special operating mode for media with increased foam build-up (→ 11.6.2
• Tank adjustment enables suppression of undesired interference
(e.g. caused by structures in the tank or when mounted in a connection piece
(→ 11.2.2))
• Display of the level and the switching status via display / LEDs
• IO-Link function (→ 6.3.7)
6.3.1 Display functions
The unit displays the current level, either in mm or in percent of the scaled
measuring range. Factory setting: mm.
The display unit is defined by programming (→ 11.3).
In the operating mode, the user can switch between mm and percentage (→ 12.6).
The set unit of measurement and the switching status of the outputs are indicated
by LEDs (→ 9).
6.3.2 Analogue function
The unit provides an analogue signal proportional to level. The analogue output
(OUT2) can be set ((→ 11.4.6) and the following illustrations).
• [ou2] defines the output function of the analogue output:
current output rising [ou2] = [I] or
current output falling [ou2] = [InEG].
• The analogue start point [ASP2] defines at which measured value the analogue
start value*)is provided (→ 11.4.7).
• The analogue end point [AEP2] defines at which measured value the analogue
end value*)is provided (→ 11.4.7).
*) The analogue start value is 4 mA with [ou2] = [I] or 20 mA with [ou2] =
[InEG].
The analogue end value is 20 mA with [ou2] = [I] or 4 mA with [ou2] = [InEG].
Minimum distance between [ASP2] and [AEP2] = 20 % of the active zone.

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Curve of the analogue signal (factory setting):
I [mA]
L
20
4
A
I2 I1
Curve of the analogue signal (measuring range scaled):
I [mA]
L
20
4
A
ASP2 AEP2
I1I2
L: level
①:
[ou2] = I (factory setting)
A: active zone = L - (I1 + I2)
②:
[ou2] = [InEG]
I1: inactive zone 1 ASP2: analogue start point
I2: inactive zone 2 (→ Technical data sheet) AEP2: analogue end point
Additional information about the analogue output: (→ 12.8)
Note the tolerances and accuracies during the evaluation of the analogue signal
(→ Technical data sheet).

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6.3.3 Switching functions
Via switching output OUT1 (factory setting) or additionally via OUT2 (can be set)
the unit signals that a set limit level has been reached or that the level is below the
limit. The following switching functions can be selected:
• Hysteresis function / normally open (Fig. 6-3): [oux] = [Hno]
• Hysteresis function / normally closed (Fig. 6-3): [oux] = [Hnc]
First the set point (SPx) is set, then the reset point (rPx) with the requested
difference.
• Window function / normally open (Fig. 6-4): [oux] = [Fno]
• Window function / normally closed (Fig. 6-4): [oux] = [Fnc]
The width of the window can be set by means of the difference between
[FHx] and [FLx]. [FHx] = upper value, [FLx] = lower value.
Fig. 6-3 Fig. 6-4
SP
rP
t
L
FH
FL
1
0
1
0
FE
Fno
Fnc
L :
HY:
FE:
level
hysteresis
window
• The adjustable limits (e.g. [SP1] / [rP1]) always refer to the lower edge of the
probe.
• For the switching output a switch-on and switch-off delay of max. 60 s can be
set (e.g. for especially long pump cycles) (→ 11.4.4).

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6.3.4 Damping function
With unsteady level (e.g. turbulence, wave movements) display and output
response can be damped. During damping the determined level values are
"smoothed" by means of a mean filter; the result is a steady curve.
Damping can be set by means of the parameter [dAP] (→ 11.4.10).
[dAP] indicates in seconds after what time 63 % of the final value is reached in the
event of a sudden jump. After 5 x [dAP] almost 100 % has been reached.
6.3.5 Probes for different tank heights
The unit can be installed in tanks of different sizes. Probes in different lengths are
available. To adapt to the tank height, each probe can be shortened. The minimum
probe length is 150 mm, the maximum probe length 2000 mm.
6.3.6 Defined state in case of a fault
• In case of a fault a state can be defined for each output.
• If a fault is detected or if the signal quality is below a minimum value, the
outputs pass into a defined state. Applies to the analogue output according to
Namur recommendation (NE43). For this case the response of the outputs can
be set via the parameters [FOU1], [FOU2] (→ 11.4.9).
• Temporary loss of signal caused e.g. by turbulence or foam build-up can be
suppressed by a delay time (parameter [dFo] → 11.4.11). During the delay time
the last measured value is frozen. If the measured signal is received again in
sufficient strength within the delay time, the unit continues to work in normal
operation. If, however, it is not received again in sufficient strength within the
delay time, the outputs pass into the defined state.
In case of heavy foam build-up and turbulence, note the examples of how
to create a steady area (→ 7.1.6)

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6.3.7 IO-Link
This unit has an IO-Link communication interface which requires an IO-Link
capable module (IO-Link master) for operation.
The IO-Link interface enables direct access to the process and diagnostic data
and provides the possibility to set the parameters of the unit during operation.
In addition, communication is possible via a point-to-point connection with a USB
adapter cable.
The IODDs necessary for the configuration of the unit, detailed information about
process data structure, diagnostic information, parameter addresses and the
necessary information about required IO-Link hardware and software can be
found at www.ifm.com.
6.3.8 Simulation functions
Various levels and errors can be simulated for set-up, maintenance or interference
reduction. The duration of the simulation can be selected (1 min...1 h). The
simulation can be started manually and runs until it is stopped manually or the
set time elapses. During the simulation the outputs respond according to the
simulated process values (→ 11.7).
7 Installation
7.1 Installation location / environment
• Vertical installation from the top is preferred.
►Observe the notes on tank adjustment (→ 7.1.7)
• Installation preferably in closed, metal tanks or bypass pipes.
• For installation in open tanks (→ 7.4.1)
• For installation in plastic tanks (→ 7.4.2).
7.1.1 Minimum distances and connection piece diameter
►Select a connection piece height that is smaller than the connection piece
diameter.

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Fig. 7-1 Fig. 7-2
without adjustment
A1
BA2A3
D
Installation distances with adjustment (→
7.1.7)
Installation distances without adjustment
A1: 10 mm A1: 10 mm
A2: 20 mm A2: 50 mm
A3: 20 mm to structures in the tank (B)
50 mm to other sensors type LR
A3: 50 mm to structures in the tank (B)
50 mm to other sensors type LR
D: ø 30 mm if installed in a connection
piece
D: No connection piece allowed
according to Fig. 7-2
7.1.2 Installation in pipes
►Installation only if hygienic requirements are met.
►Only install the unit in metal pipes.
►The internal pipe diameter d must at least have the following value:
With adjustment(→ 7.1.7) Without adjustment
dø 30 mm
ø100 mm with [MEdI] = [HIGH]
ø250 mm with [MEdI] = [MId] (→
11.6.2)

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7.1.3 Applications with viscous and fast flowing media
For applications with viscous or flowing media and / or agitators in which the probe
is exposed to lateral load:
►Probe must not be in contact with tank
wall / structures.
►Increase lateral minimum distances
according to the probe length and the
lateral deflection to be expected.
►If possible, fix the probe at the
tank bottom so that it is electrically
conductive. This can be done by means
of a sleeve or similar devices (Fig. 7-3).
►Check the correct function (in particular
with empty tank).
Fig. 7-3
7.1.4 Fill openings
Do not install the unit in the immediate vicinity of a fill opening (Fig. 7-4).
Fig. 7-4

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7.1.5 Heavy soiling
If the medium is highly polluted, there is the risk that a bridge forms between the
probe and the tank wall or structures in the tank.
►Increase minimum distances depending on the pollution intensity.
7.1.6 Heavy foam build-up and turbulence
Heavy foam build-up and turbulence may lead to incorrect measurements.
To avoid this
►install the sensor in a steady area by meeting the hygienic requirements.
Examples how to create a steady area:
• Installation in metal bypass or metal still pipe (Fig. 7-5).
• Separation of the installation location by metal sheets / perforated
sheets (without figure).
Fig. 7-5
d
d
AB
CD
d: minimum diameter (→ 7.1.2)
The upper access to the steady area (A, B) must be above the max. level.
The lower access (C, D) or the area with perforated sheet must be below
the min. level. This ensures that neither foam nor turbulence impact the
sensor zone. When perforated sheets or similar are used, soiling (e.g.
solids in the medium) can also be avoided.

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With increased foam build-up the setting [MEdI] = [MId] (→ 11.6.2) is
recommended.
7.1.7 Notes on tank adjustment
Tank adjustment (parameter [tREF]) reduces the effect of interference and
ensures a higher excess gain in difficult application conditions.
Carry out the tank adjustment only when the unit is installed.
For the tank adjustment it is necessary to enter an "adjustment distance" first.
Within this distance, starting from the process connection, interfering reflections
are compensated.
►Select an adjustment distance (a) so that the connection piece (S) and
structures in the tank (B) are completely detected.
►Observe safety distance (b ≥250 mm) to the level or the end of the probe.
b
a
B
S
a:
b:
S:
B:
adjustment distance (min: 10 mm; max: L - 250 mm)
safety distance to the level or end of the probe: b ≥ 250 mm
connection piece
structures in the tank
For probe lengths L < 260 mm no tank adjustment is possible. The
parameter [tREF] is then not available. In this case:
►Adhere to all indicated installation distances (→ 7.1).

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No tank adjustment is necessary if all installation distances (→ 7.1) are
adhered to. The unit is then ready for operation without adjustment.
►In case of doubt carry out a tank adjustment (recommended!).
Carry out a tank adjustment with empty tank, if possible, to detect any
possible sources of interference. In this case:
►Select the max. adjustment distance (L - 250 mm).
Only if data storage is required in an IO-Link application:
The tank adjustment is not saved via IO-Link!
After a replacement it must be carried out again.
More information about data storage (→ 16.2)
7.2 Probe installation
The probe is not supplied, but one of the optional items must be ordered
separately (→ 3 Items supplied).
7.2.1 Attaching the probe
Do not damage the surfaces of the process connection and the probe.
►Use suitable tools with plastic surfaces.
Fixing of the probe:
►Remove the protective cover / protective devices
from the unit and the probe.
►Slip the supplied O-ring onto the probe connection
of the unit or check its position.
►Screw the probe to the unit and tighten it.
Recommended tightening torque: 6.5 Nm.
►Check the O-ring for correct position.
Replace if damaged.
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In case of high mechanical stress (strong vibration, moving viscous media) it
may be necessary to secure the screw connection, e.g. by a screw retaining
compound.
Substances such as screw retaining compounds may migrate into the
medium.
►Make sure that they are harmless.

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7.3 Probe length
7.3.1 Shorten the probe
The probe can be shortened to adapt to different tank heights.
Ensure that the probe length is not below the minimum permissible probe
length (Lmin) of 150 mm. The unit does not support probe lengths below
150 mm.
With probe lengths < 260 mm no tank adjustment is possible (→ 7.1.7).
Proceed as follows:
►Screw the pobe to the unit.
►Mark the desired length (L) on the probe. The
reference point is the lower edge of the process
connection.
►Remove the probe from the unit. Make sure that the
O-ring between the probe attachment piece and the
probe does not get lost.
►Shorten the probe at the mark.
►Remove all burrs and sharp edges. For hygienic
requirements: Restore the required surface quality.
If necessary, repolish.
Lmin
L
►Check the position of the O-ring / insert the O-ring again.
►Screw the probe to the unit again and tighten it. Recommended tightening
torque: 6.5 Nm.
In case of high mechanical stress (strong vibration, moving viscous media) it
may be necessary to secure the screw connection, e.g. by a screw retaining
compound.
Substances such as screw retaining compounds may migrate into the
medium.
►Make sure that they are harmless.

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7.3.2 Determine probe length
►Precisely measure the probe length L. The reference point is the lower edge of
the process connection (figure above).
► Note the value. It is needed for setting the device parameters (→ 11.2.1).
7.4 Installation of the unit in the tank
Before installing and removing the unit: Make sure that no pressure is
applied to the system and that there is no medium in the tank that could
leak. Also always take into account the potential dangers related to extreme
machine and medium temperatures.
The unit can be fixed to different process connections (→ Accessories). Options
are as follows:
1 Fitting by means of a mounting or welding adapter with a sealing ring (hygienic)
The adapter is supplied with an EPDM O-ring. Further sealing rings (e.g. FKM O-ring)
are available as accessories.
Concerning installation → Installation instructions of the adapter.
2 Installation on G1 flange (non hygienic)
The sealing ring on the sensor is used as process seal.
The upper sealing area on the process connection must be flush with the tapped hole
and have a surface characteristic of min. Rz 6.3.
The sensor housing cannot be aligned. With non alignable process
connections (e.g. welding adapters) note the desired position of the sensor
housing (readability of the display, cable entry). Observe marks at adapters.
If necessary, screw in the unit and mark the required orientation.
If no other installation instructions apply, proceed as follows:
►Lightly grease the thread of the sensor using a lubricating paste which is
suitable and approved for the application.
►Insert the unit into the process connection.
►Tighten it using a spanner. Tightening torque: 35 Nm