LT8924 - Temperature Controller IFM - Free user manual and instructions

USER MANUAL LT8924 IFM

Operating instructions

Electronic sensor for level and temperature

LT89xx

Contents

1 Preliminary note 4

1.1 Symbols used 4
1.2 Warnings used 4

2 Safety instructions.... 5

3 Intended use.... 6

3.1 Application area 6

3.1.1 Restriction of the application area 6

4 Function 7

4.1 Features of the unit 7
4.2 Measuring principle level.... 7
4.3 Measuring principle temperature.... 7
4.4 Operating modes 8
4.5 Notes on the integrated overflow prevention 8
4.6 Display function.... 8
4.7 Switching function 9
4.8 Offset for indicating the real level in the tank.... 9
4.9 Defined state in case of a fault 10
4.10 Extreme value memory 10

5 Installation.... 11

5.1 Notes on installation instructions for the operation with overflow prevention ..... 11
5.2 Installation instructions for the operation without overflow prevention 12

5.2.1 Installation in the inactive zone 12
5.2.2 Installation in the active zone 12

5.3 Other installation notes 13

5.3.1 Marking of the installation height.... 13

6 Electrical connection.... 15
7 Operating and display elements 17
8 Menu.... 18

8.1 Menu structure: 18

9 Parameter setting 20

9.1 IO-Link 20
9.2 Notes on parameter setting via IO-Link 20
9.3 Parameter setting in general 21
9.4 Getting started 23

9.4.1 Example configuration 1 23
9.4.2 Example configuration 2 23

9.5 Basic settings 24

9.5.1 Assign process values to the outputs 24
9.5.2 Assign process values to the display.... 24
9.5.3 Offset setting.... 24
9.5.4 Set medium.... 25
9.5.5 Set overflow prevention.... 25
9.5.6 ▶ Adjust overflow prevention 25

9.6 Setting of output signals 26

9.6.1 Setting the output function.... 26
9.6.2 Setting the switching limits (hysteresis function) 26
9.6.3 Setting the switching limits (window function) 27
9.6.4 Defining the switching delay for the switching output. 27
9.6.5 Defining the switch-off delay for the switching output 27
9.6.6 Setting the switching logic for the output 27
9.6.7 Response of the outputs in case of a fault. 27
9.6.8 Configuration of the display.... 27
9.6.9 Resetting all parameters to factory setting 28

9.7 Setting values / setting ranges 28

9.7.1 Setting values [OFS] 28
9.7.2 Setting ranges switching limits for level.... 28

9.7.3 Setting ranges switching limits for temperature 28
9.7.4 Setting values for [OP] 28
9.7.5 Calculation aids [OP] 29

9.7.5.1 Definition"from the cover" 30

9.7.5.2 Definition"from the bottom" 30

10 Operation 31

10.1 Operating indicators 31
10.2 Display the set parameters 31
10.3 Read / reset extreme value memory temperature 31
10.4 Fast selection level / temperature 31
10.5 Error indications 32
10.6 Output response in different operating states 32

11 Maintenance, cleaning, change of medium 33

11.1 Maintenance information for the operation without overflow prevention 33

12 Applications 34

12.1 Storage tank 34
12.2 Pumping station 34

13 Factory setting 36

1 Preliminary note

You will find instructions, technical data, approvals and further information using the QR code on the unit / packaging or at www.ifm.com.

1.1 Symbols used

√ Requirement
Instructions
Reaction, result

[...] Designation of keys, buttons or indications

→ Cross-reference

Important note

Non-compliance may result in malfunction or interference.

Information

Supplementary note

1.2 Warnings used

CAUTION

Warning of personal injury

▷ Slight reversible injuries may result.

2 Safety instructions

• The unit described is a subcomponent for integration into a system.
• The system architect is responsible for the safety of the system.
• The system architect undertakes to perform a risk assessment and to create documentation in accordance with legal and normative requirements to be provided to the operator and user of the system. This documentation must contain all necessary information and safety instructions for the operator, the user and, if applicable, for any service personnel authorised by the architect of the system.
• 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 (→ Intended use).
• 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.
• Only use the product for permissible media (→ Technical data).
• 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.

CAUTION

The surface of the unit may get hot if the switching outputs are operated at maximum load.

▷ Risk of burns

▶ Do not touch the unit.

▶ Protect the housing against contact with flammable substances and unintentional contact.

3 Intended use

3.1 Application area

The unit was especially designed to meet the requirements of machine tool building. It is particularly suitable for monitoring coolant emulsions (also dirty) as well as cutting and hydraulic oils.

The unit monitors 2 process values: level and temperature.

3.1.1 Restriction of the application area

• The unit is not suitable for:

– acids and alkalis.
– hygienic and electroplating applications.
– highly conductive and adhesive media (e.g. glue, shampoo).
– granulates, bulk material.
– use in grinders (increased risk of formation of deposits).

- It is possible that foam of good conductivity is detected as level.

▶ Check the correct function by performing an application test.
- For water and hydrous media with temperatures > 35 °C, install the unit in a climatic tube (→ Accessories).
• For automatic medium detection:

For media which are very inhomogeneous, separate from each other thus forming separation layers (e.g. oil layer on water) the following applies:

▶ Check the correct function by performing an application test.

4 Function

This unit has an IO-Link communication interface which enables direct access to process and diagnostic data. In addition it is possible to set the parameters of the unit while it is in operation. Operation of the unit via the IO-Link interface requires an IO-Link master.

With a PC, suitable IO-Link software and an IO-Link adapter cable, communication is possible while the system is not in operation.

The IODDs necessary for the configuration of the unit, detailed information about process data structure, diagnostic information, parameter addresses and the necessary information about the required IO-Link hardware and software can be found at www.ifm.com.

4.1 Features of the unit

The unit can be installed in tanks of different sizes.

▶ Observe the notes on installation!

4 outputs are available. They can be set separately.

OUT1:	• Switching signal for level limit value / IO-Link
OUT2:	• Switching signal for level limit value
OUT3:	• Switching signal for level limit value
OUT4:	or• Switching signal for temperature limit

4.2 Measuring principle level

The sensor determines the level according to the capacitive measuring principle.

An electrical field (E) is generated and influenced by the medium to be detected. This change to the field causes a measurement signal that is electronically evaluated.

The dielectric constant of a medium is important for its detection. Media with a high dielectric constant (e.g. water) generate a strong measurement signal, media with a low dielectric constant (e.g. oils) a correspondingly lower signal.

The active measurement zone of the sensor probe is composed of 16 capacitive measuring segments. They generate measurement signals depending on the degree of coverage.

I: Inactive zone

A: Active zone (16 active segments)

E: Electrical field

Dimensions: www.ifm.com, → Data sheet

4.3 Measuring principle temperature

The temperature is detected by a Pt element at the lower end of the probe and electronically evaluated.

• Media without water content (e.g. oils) are detected directly (in contact with the medium).
• Water-based media can also be detected directly up to temperatures of 35\ °C .

For temperatures > 35 °C a climatic tube has to be installed for use in water-based media. That means that temperature detection is indirect (not in contact with the medium).

4.4 Operating modes

For adjustment to existing application:

▶ Select the required operating mode.

- Manual media selection with overflow prevention (factory setting):

Recommended! Highest operational reliability!

The medium to be detected is set manually [MEdI]. In addition, an integrated, independently functioning overflow prevention is available.

- Manual media selection without overflow prevention:

Medium operational reliability!

The medium to be detected is set manually as described under 1. However, the overflow prevention is deactivated. For this reason, no adjustment is required.

• Automatic medium detection:

Lowest operational reliability!

Each time the operating voltage is switched on, the unit adjusts itself to the medium and the installation environment.

For automatic media detection, no overflow prevention is available!

Automatic media detection can only function properly under certain conditions (e.g. compliance with special mounting specifications, restrictions for operation and maintenance).

4.5 Notes on the integrated overflow prevention

With the parameter [OP] (OP = overflow prevention), one of the upper measuring segments is defined as integrated overflow prevention OP.

If the overflow prevention OP is activated, an adjustment to the installation situation has to be made [cOP]. Otherwise, the unit is not ready for operation; during this time, [ ] is shown in the display.

The overflow prevention OP can be deactivated ([OP] = [OFF]).

Deactivating the overflow prevention OP can impair the operational reliability. For optimum operation and maximum operational reliability, we therefore recommend to not deactivate the overflow prevention OP.

The overflow prevention OP is the maximum limit of the measuring range. The switch point [SP1] / [FH1] is always below [OP]!

The overflow prevention OP is not assigned to a separate output! It offers additional protection and only switches if, as the level rises, the switching output has not switched even though the corresponding switch point has been exceeded (e.g. due to application-related malfunctions).

Typically the overflow prevention OP reacts when the selected measuring segment has been reached (a few mm before the set OP value).

The overflow prevention OP reacts immediately and without delay. The set delay times (e.g. of a switch point directly below) have no effect on the overflow prevention OP.

The response of the overflow prevention OP is indicated on the display ("Full" and indication of the current level change every second).

4.6 Display function

The device displays the current level / the current temperature. The switching status of the switching output is indicated by an LED.

The process value (level / temperature) can be changed temporarily in the operating mode:

▶ Briefly press [Set].
▷ Display of the other unit of measurement for 30 s; the respective LED is lit.

4.7 Switching function

The unit signals via 4 switching outputs that a set limit level has been reached or that the level is below the limit value.

• Outputs OUT1 / OUT2 are assigned to the process value level.
  • Outputs OUT3 / OUT4 are freely programmable:

Parameter [SEL3] / [SEL4] assigns the process value, level / temperature, to the outputs OUT3 / OUT4.

Selectable switching functions:

• Hysteresis function / normally open: [oux] = [Hno].
• Hysteresis function / normally closed: [oux] = [Hnc].

First the set point (SPx) is set, then the reset point (rPx) with the requested difference.

The hysteresis for the overflow prevention OP is fixed.

• Window function / normally open: [oux] = [Fno].
• Window function / normally closed: [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. 1: Hysteresis function normally open / normally closed

Fig. 2: Window function normally open / normally closed

L: Level

T: Temperature

HY: Hysteresis

FE: Window

4.8 Offset for indicating the real level in the tank

The zone between tank bottom and lower edge of the probe can be entered as offset value [OFS]. So display and switch points refer to the actual level (point of reference = tank bottom).

For [OFS] = [0]: The reference point is the lower edge of the measuring probe.

The set offset only refers to the display on the unit. It has no effect on the analogue output and the process value transmitted via IO-Link. The OFS parameter, however, is correctly transmitted via IO-Link and can therefore be taken into account.

4.9 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. For this case the response of the outputs can be set via the parameters [FOU1] ... [FOU4].

4.10 Extreme value memory

The minimum and maximum values of the temperatures occurred since the last memory reset can be retrieved via the menu items [Lo. T] and [Hi. T].

5 Installation

CAUTION

The surface of the unit may get hot if the switching outputs are operated at maximum load.

▷ Risk of burns
▶ Do not touch the unit.
▶ Protect the housing against contact with flammable substances and unintentional contact.

L: Probe length

M: Zone for mounting element

c: Max. outside length

u...y: Minimum distances

OP: Overflow prevention

B: Metal object inside the tank

	LT8922	LT8923	LT8924
	[cm]	[cm]	[cm]
L (rod length)	26.4	47.2	72.8
M (mounting zone)	14.0	23.0	36.0
c (max. outside length)*

* Applies to the installation as shown (the wall thickness of the tank lid was neglected; the mounting element does not protrude inside the tank).
▶ Otherwise: note mounting zone M.

5.1 Notes on installation instructions for the operation with overflow prevention

▶ [MEdI] = [CLW..] or [OIL..]
▶ [OP] = [value ...] (Overflow prevention OP activated!)

It is permitted to fix the mounting elements within the mounting zone (M) ( → Installation).

▶ Adhere to the maximum permitted outside length (c) ( → Installation).
▶ Observe minimum distances ( → Installation).
▶ Observe the notes on the integrated overflow prevention OP.

The overflow prevention OP must:

1. be below the mounting element
2. be set at a minimum distance (y) to it. The minimum distance is measured between the lower edge of the mounting element and the OP value.

	MEdl = CLW.1	MEdl = CLW.2, OIL.1	MEdl = OIL.2
	[cm]	[cm]	[cm]
x	2.0	3.0	4.0
u	1.0	1.0	1.0
y (LTx922)	2.5	3.5	4.5
y (LTx923)	4.5	5.5	6.5
y (LTx924)	6.0	7.0	8.0
v	4.5	4.5	4.5
w	4.0	5.0	6.0

More information [OP]: → calculation aids [OP]

5.2 Installation instructions for the operation without overflow prevention

▶ [MEdI] = [Auto] or [OP] = [OFF] (overflow prevention OP deactivated!)

5.2.1 Installation in the inactive zone

Between the maximum level (b1) and the inactive zone (l1), the minimum distance (a1) has to be adhered to!

▶ Fix the unit using mounting elements in the inactive zone (I1). The outside length (c) must not exceed (I1) ( → Table).
▶ Ensure that the maximum level (b1) is not exceeded after completed installation ( → Table).
▶ Further minimum distances must be adhered to: Installation in the active zone ( → ☐ 12)

I1 / I2: Inactive zones

A: Active zone
a1: Minimum distance between the inactive zone (I1) and the maximum level (b1)
b1: Max. level from the lower edge of the sensor (without offset)
c: Outside length

	LTx922	LTx923	LTx924
	[cm]	[cm]	[cm]
I1	5.3	6.0	10.4
A	19.5	39.0	58.5
a1	1.0	1.5	2.5
b1	20.0	39.5	59.5

5.2.2 Installation in the active zone

Between the maximum level (b2) and the mounting element a minimum distance (a2) has to be observed!

c: Outside length
a2: Minimum distance between mounting element and maximum level (b2).
b2: Max. level from the lower edge of the sensor.

	MEdI = CLW.1	MEdI = CLW.2, OIL.1	MEdI = OIL.2/ Auto
	[cm]	[cm]	[cm]
x:	2.0	3.0	4.0
u:	1.0	1.0	1.0
a2 (LTx922):	2.0	2.5	3.0
a2 (LTx923):	4.0	4.5	5.0
a2 (LTx924):	6.0	7.0	8.0
v *)	4.5	4.5	4.5
w *)	4.0	5.0	6.0

*) → Installation

In case of automatic medium detection [MEdl] = [Auto] or deactivated overflow prevention [OP] = [OFF], the sensor reinitialises itself each time it is switched on and makes adjustments to the medium and the installation environment. The active zone / measuring range must not be completely covered by the medium. The indicated minimum distances ensure this. Too short a distance may lead to maladjustments and malfunctions.

5.3 Other installation notes

▶ For mounting in plastic pipes/plastic tanks the inside (pipe) diameter must be min. 12 cm. Install sensor in the centre.
▶ For mounting in metal pipes the inside pipe diameter (d) must be at least:

	MEdI = CLW.1	MEdI = CLW.2, OIL.1	MEdI = OIL.2 / Auto
	[cm]	[cm]	[cm]
d:	4.0	6.0	10.0

5.3.1 Marking of the installation height

▶ Fix the set installation height with the supplied stainless steel tube clip.

If the sensor is removed from the fixture for maintenance reasons, the clip serves as a limit stop when remounting the sensor. Thus an inadvertent maladjustment of the sensor is excluded. This is particularly necessary for the correct function of the overflow prevention OP.

▶ Fit the stainless steel tube clip using pliers.
▶ Ensure a safe fit.
▶ To remove the clip it has to be destroyed.

6 Electrical connection

The unit must be connected by a qualified electrician.

The national and international regulations for the installation of electrical equipment must be adhered to.

Supply voltage SELV, PELV according to the technical data sheet.

▶ Disconnect power.
▶ Connect the unit as follows:

When the unit is supplied with operating voltage for the first time, the probe length, the medium to be detected and the type of probe used must be entered. Only then is the unit ready for operation.

Pin	Core colour
1:	BN	Brown
2:	WH	White
3:	BU	Blue
4:	BK	Black
5:	GY	Grey
6:	PK	Pink
7: not used	VT	Violet
OUT1:Switching output (level)IO-Link
OUT2:Switching output (level)
OUT3:Switching output (level / temperature)
OUT4:Switching output (level / temperature)
Colours to DIN EN 60947-5-2

▶ For safe function, the sensor housing must be electrically connected to the counter-electrode (grounding).
▶ Use the housing connection (see drawing) and a short piece of cable with a wire cross-section of at least 1.5 mm² .
▶ For plastic tanks, a counter-electrode must be provided, e.g. a metal plate inside the tank in parallel with the probe. Adhere to minimum distances to the probe.

Circuit examples:

1: 4 x positive switching

2: 4 x negative switching

7 Operating and display elements

1 to 8: Indicator LEDs
LED 1	Indication in centimetres.
LED 2	not used.
LED 3	Indication in °C.
LED 4	not used.
LED 5	Switching status OUT4 (lights when output 4 is switched)
LED 6	Switching status OUT3 (lights when output 3 is switched)
LED 7	Switching status OUT2 (lights when output 2 is switched)
LED 8	Switching status OUT1 (lights when output 1 is switched)
9: Mode/Enter button
• Selection of the parameters and acknowledgement of the parameter values.
10: Set button
• Setting of the parameter values (scrolling by holding pressed, incrementally by pressing once).
11: Alphanumeric display, 4 digits
• Display of the current level / the current temperature.• Display of the operating and fault indication.• Indication of the parameters and parameter values.

8 Menu

8.1 Menu structure:

Menu items highlighted in grey are active depending on the configuration of the output.

9 Parameter setting

CAUTION

The surface of the unit may get hot if the switching outputs are operated at maximum load.

▷ Risk of burns
▶ Do not touch the unit.
▶ Protect the housing against contact with flammable substances and unintentional contact.

The parameters can be set via the buttons on the device or the IO-Link interface.

During parameter setting the unit remains in the operating mode internally. It continues its monitoring functions with the existing parameters until the parameter setting has been completed.

9.1 IO-Link

IO-Link is an internationally standardised IO technology (IEC 61131-9) for communicating with sensors and actuators.

Further information about IO-Link at: www.io-link.com

IO-Link offers the following advantages:

• Noise-immune transmission of several process values.
  • Parameter setting during operation as well as point-to-point at the desk.
  • Device diagnostics (events)
  • Data storage: Automatic new parameter setting in case of replacement.
  • Detection of connected units.
  • Freely definable parameters to identify the units in the plant.

Information and documentation on the IO-Link interface at: www.io-link.ifm

9.2 Notes on parameter setting via IO-Link

On delivery the unit is not operational.

First, the integrated overflow prevention OP has to be adjusted.

Depending on the application, OP adjustment can be carried out in different ways:

▶ Directly on the display.
▶ Via an IO-Link tool (e.g. LR DEVICE), button "Teach_OP [cOP]".
▶ Via the controller: write the value 208 to the IO-Link index 2 (length: 1 byte).

The OP adjustment is not part of the data storage.

Therefore, a simple replacement (e.g. in case of a unit failure) is only possible with reservations: On the new unit, the OP adjustment has to be carried out manually (optionally via the operating keys or via IO-Link). Only when the OP adjustment has been carried out successfully does the unit revert to the cyclical process data transmission.

After a factory reset (button "Restore Factory Settings"), the device reboots and the factory settings are restored.

9.3 Parameter setting in general

3 steps must be taken for each parameter setting:

1: Select Parameter

▶ Press [Mode/Enter] until the requested parameter is displayed.

2: Set parameter value

▶ Press [SET] and keep it pressed.
▷ Current setting value of the parameter flashes for 5 s.
▷ After 5 s: The Setting value is changed. Incrementally by pressing the button once or continuously by keeping the button pressed.
▷ The numerical values are incremented continuously:

For reducing the value:

▶ Let the display move to the maximum setting value. Then the cycle starts again at the minimum setting value.

3: Acknowledge parameter value

▶ Briefly press [Mode/Enter].
▷ The parameter is displayed again. The new setting value is saved.

Setting of other parameters:

▶ Start again with step 1.

Finishing the parameter setting:

▶ Press [Mode/Enter] several times until the current measured value is displayed, or wait for 30 s.
▷ The sensor returns to the process value display.

If [C. Loc] is displayed when you try to change a parameter value, a parameter setting process is active via the IO-Link communication (temporary locking).

If [S. Loc] is displayed, the sensor is permanently locked via software. This locking can only be removed with a parameter setting software.

Change from menu level 1 to menu level 2:

▶ Press [Mode/Enter] until [EF] is displayed.

▶ Briefly press [Set].
▷ The first parameter of the submenu is displayed (here: [rES]).

Lock / unlock

The unit can be locked electronically to prevent unintentional settings.

Locking:

▶ Make sure that the unit is in normal operating mode.
▶ Press [Mode/Enter] + [Set] simultaneously for 10 s.
▷ [Loc] is displayed.

[Loc] is briefly displayed if you try to change parameter values.

Unlocking:

▶ Press [Mode/Enter] + [Set] simultaneously for 10 s.
▷ [uLoc] is displayed.

Timeout:

If no button is pressed for 30 s during parameter setting, the unit returns to the operating mode with unchanged values. (Exception cOP)

The unit can be configured before or after installation. Exception: To adjust the overflow prevention [cOP], the unit must be installed in the tank.

9.4 Getting started

For fast set-up, the example configurations described in the following can be used for most applications. The indicated minimum distances apply exclusively to each separately described case.

9.4.1 Example configuration 1

Unit:	LTx922 (probe length L= 264 mm)
Medium to be detected:	Mineral oil
Operating mode:	Manual media selection with overflow prevention (factory setting)
Installation environment:	Metal tank

x: min. 4.0 cm
u: min. 1.0 cm
c: max. 14.0 cm

▶ Install unit.
▶ Observe the distances (x), (u) and (c):
▶ Ground sensor and tank via an electrical connection.
▶ Observe the parameter setting sequence:

• [MEdl] = [OIL.2]
• [OFS] = (u); e. g. (u) = 2.0 cm
- [OP] = Set the overflow prevention OP at a distance (y) greater than 4.5 cm below the mounting element.

For distances (y) smaller than 4.5 cm there may be malfunctioning and error messages during the adjustment process [cOP].

Step increment and setting range: → Setting values [OP] Calculation aids for [OP]: → Calculation aids [OP]

▶ Adjust overflow prevention OP to [cOP].
▷ The unit is ready for operation.
▶ Make further settings if necessary.
▶ Check whether the unit operates correctly.

9.4.2 Example configuration 2

Unit:	LTx923 (probe length L= 472 mm)
Medium to be detected:	Coolant emulsion
Operating mode:	Automatic medium detection
Installation environment:	Metal tank.

x: min. 4.0 cm
u: min. 1.0 cm
c: max. 23.0 cm

▶ Install unit.
▶ Observe the distances (x), (u) and (c):
▶ Ground sensor and tank via an electrical connection.
▶ Observe the maximum permitted level (b).
▶ Observe the parameter setting sequence:

• [MEdl] = [Auto]
• [OFS] = (u), e.g. (u) = 1.0 cm
- [SP1] = Set the switch point at a distance (a2) greater than 5.0 cm below the mounting element.

A distance (a2) greater than 5.0 cm has to be observed between maximum level (b) and mounting element.

Switch points [SP3] and [SP4] can be used to control the medium temperature and to set limit values for early warning / alarm.

If the unit must be reinitialised:

▶ Switch the operating voltage off and on again.
▷ The unit is ready for operation.
▶ Make further settings if necessary.
▶ Check whether the unit operates correctly.

9.5 Basic settings

9.5.1 Assign process values to the outputs

Outputs OUT1 and OUT2: Assigned to the process value level.

Outputs OUT3 and OUT4: Programmable.

▶ Select [SEL3] / [SEL2]:	[SEL3]
▶ Assign process value to the output OUT3 / OUT4.	[SEL4]
[LEVL] = the process value level is assigned to the output.
[TEMP] = the process value temperature is assigned to the output.

9.5.2 Assign process values to the display

▶ Select [SELd]:▶ Select the process value to be displayed. [LEVL] = level is displayed. [TEMP] = temperature is displayed.

[SELd]

9.5.3 Offset setting

The distance between tank bottom and lower edge of the measuring probe can be entered as offset value.

Set [OFS] before entering the values for SPx, rPx and OP. This avoids accidental incorrect settings!

▶ Select [OFS]:▶ Set the value for the offset.

[OFS]

9.5.4 Set medium

▶ Select [Medl]:▶ Set sensitivity matching the medium to be detected:	[Medl]
[CLW.1] = Water, water-based media, coolant emulsions.
[CLW.2] = Water, water-based media, coolant emulsions for temperatures > 35 °C (installation in climatic tube).
[OIL.1] = Oils with an increased dielectric constant (e.g. some synthetic oils).
[OIL.2] = Oils with a low dielectric constant (e.g. mineral oils).
[Auto] = Automatic medium detection.

▶ In case of doubt, select [OIL.2] for oils.
▶ Check proper function by performing an application test!

The settings [CLW.1] and [CLW.2] suppress deposits (e.g. metal swarf).

The settings [OIL.1] and [OIL.2] suppress a bottom layer of higher dielectric water or swarf which is a few cm high. If no oil layer is present (or if it is very thin), the bottom layer is detected.

With the setting [MEdl] = [Auto], no overflow prevention OP is available. In that case, the menu items [OP] and [cOP] are not available.

9.5.5 Set overflow prevention

▶ Comply with minimum distances and installation instructions. ▶ Select [OP]. ▶ Define the position of the overflow prevention OP. The option [OP] = [OFF] deactivates the overflow prevention OP.

[OP]

▶ Set [OP] before [SPx] or [FHx].
▷ [SPx] / [FHx] decreases if [OP] is set to a value ≤ [SPx] / [FHx] after setting [SPx] / [FHx].
▷ If [OP] and [SPx] / [FHx] are close to each other (1 x step increment), [SPx] / [FHx] increases if [OP] increases.

If the overflow prevention is deactivated, [OP] = [OFF] or [MEdl] = [Auto] , the reliable function of the sensor must be verified with particular care. Switch-on and switch-off processes and special operating states such as very full tanks, possible maintenance and cleaning operations are to be considered in the verification.

With the setting [OP] = [OFF] , the parameter [cOP] is not available.

9.5.6 Adjust overflow prevention

Only adjust the overflow prevention OP when the unit is installed.

If possible, carry out the adjustment when the tank is empty. The tank may be partly filled.

▶ Make sure that the overflow prevention OP is not covered by the medium! Observe the minimum distance between the overflow prevention OP and the level.

▶ Select [cOP]. ▶ Press [SET] and keep it pressed. ▷ [cOP] flashes for some seconds; then the continuous display indicates that the adjustment is being made. ▷ If the adjustment is successful, [donE] is displayed. ▶ Confirm with [Mode/Enter]. ▷ If the adjustment is not successful, [FAIL] is displayed. ▶ If necessary, lower the level or correct the position of the overflow prevention [OP] and repeat the adjustment operation.

[cOP]

Minimum distance between the overflow prevention OP and the level during adjustment:

	[cm]
LTx922	2.0
LTx923	3.5
LTx924	5.0

The position of the overflow prevention OP can be determined by calling up the parameter [OP]. Note the offset if necessary.

The current level is to be determined manually since the unit is not yet ready for operation before the adjustment.

When the overflow prevention is activated ([OP] = [value...]), an adjustment [cOP] must be carried out each time:

• [MEdl] or [OP] was changed. In this case [≡≡≡] is displayed.
• The installation position (height, orientation) was changed.
• The connection between the sensor and the tank ground (e.g. cable length) was changed.

With deactivated overflow prevention [MEdl] = [Auto] or [OP] = [OFF] it is necessary for the unit for applying the basic settings and adaptation to the medium and installation environment:

- to be installed in the application

- to be reinitialised.

▶ Switch the operating voltage off and on again.

9.6 Setting of output signals

9.6.1 Setting the output function

▶ Select [OU1]... [OU4] and set the switching function:• [Hno] = hysteresis function/normally open• [Hnc] = hysteresis function/normally closed• [Fno] = window function/normally open• [Fnc] = window function/normally closed Note: if the switch point is used as an overflow prevention, the setting OUx = Hnc (NC function) is recommended. The principle of normally closed operation ensures that wire break or cable break is also detected.

[OU1]... [OU4]

9.6.2 Setting the switching limits (hysteresis function)

▶ Make sure that for the corresponding output [OUx] the function [Hno] or [Hnc] is set. Select [SP1]... [SP4] and set the value at which the output switches.	[SP1]... [SP4]
▶ Select [rP1]... [rP4] and set the value at which the output is reset.	[rP1]
rPx is always smaller than SPx. The device only accepts values which are lower than the value for SPx.	...
	[rP4]

9.6.3 Setting the switching limits (window function)

▶ Make sure that for the corresponding output [OUx] the function [Fno] or [Fnc] is set. Select [FH1]... [FH4] and set the upper limit of the acceptable range.	[FH1]... [FH4]
Select [FL1]... [FL4] and set the lower limit of the acceptable range. FLx is always lower than FHx. The device only accepts values which are lower than the value for FHx.	[FL1]... [FL4]

9.6.4 Defining the switching delay for the switching output

▶ Select [dSx] and set the value between 0.0 and 60 s. At 0.0 (= factory setting) the delay time is not active. The switching delay reacts according to VDMA.

[dS1]... [dS4]

9.6.5 Defining the switch-off delay for the switching output

▶ Select [drx] and set the value between 0.0 and 60 s. At 0.0 (= factory setting) the delay time is not active. The switch-off delay reacts according to VDMA.

[dr1]... [dr1]

9.6.6 Setting the switching logic for the output

▶ Select [P-n] and set [PnP] or [nPn].

[P-n]

9.6.7 Response of the outputs in case of a fault

▶ Select [FOUx] and set the value:[on] = the switching output switches ON in case of a fault. In case of a fault, the analogue output switches to: > 21 mA / 10 V[OFF] = The switching output switches OFF in case of a fault. In case of a fault, the analogue output switches to: < 3.6 mA / 0 V[OU] = The output reacts according to process value (if possible). Faults: faulty hardware, too low a signal quality, untypical level curve. Overflow is not considered to be a fault!

[FOU1]... [FOU4]

9.6.8 Configuration of the display

▶ Select [diS] and set type of indication:• [On] = The display is switched on in the operating mode. (Update of the measured values 500 ms).• [OFF] = The display is switched off in the operating mode. When one of the buttons is pressed, the current measured value is displayed for 30 s. The indicator LEDs remain active even if the display is deactivated.

[diS]

9.6.9 Resetting all parameters to factory setting

► ▶ Select [rES], then press [Set] and keep it pressed until [----] is displayed.► ▶ Briefly press [Mode/Enter]. ▷ The device reboots and then the factory settings are restored. Note: on delivery the device is not operational. First, the basic settings must be entered.

[rES]

9.7 Setting values / setting ranges

9.7.1 Setting values [OFS]

	[cm]
Setting range	0...200.0
	LTx922 / LTx923	LTx924
Step increment	0.5	1

If values for [OFS] are entered, the "Setting ranges switching limits for level" and "Setting values for [OP]" increase by this OFS value!

9.7.2 Setting ranges switching limits for level

The values in the table apply to [OFS] = [0]. If [OFS] > [0], they increase by the set OFS value.

	LT8922	LT8923	LT8924
	[cm]	[cm]	[cm]
[SPx] / [FHx]	2.5...20.0	3.5...39.0	6...59
[rPx] / [FLx]	2.0...19.5	3.0...38.5	5...58
Step increment	0.5	0.5	1

9.7.3 Setting ranges switching limits for temperature

	[°C]
[SPx] / [FHx]	-19.5...90
[rPx] / [FLx]	-20...89.5
Step increment	0.5

9.7.4 Setting values for [OP]

The values in the table apply to [OFS] = [0]. If [OFS] > [0], they increase by the set OFS value.

LTx922	LTx923	LTx924
[cm]	[cm]	[cm]
20.4 (1)	40.7 (1)	61 (1)
19.1	38.3	57
17.9	35.8	53
16.7	33.4	50
15.5	31.0	46
14.3	28.5	42
13.0	26.1	39
11.8	23.6	35
10.6	21.2	31
9.4	18.8	28
8.2	16.3	24
6.9 (2)	13.9 (2)	20 (2)

Fig. 3: OPx: Setting range [OP]

The indicated values for [OP] refer to the distance between OP and the lower edge of the probe.

The values apply if [OFS] = [0]!

With [OFS] > [0] the values increase by the set OFS value!

Example LTx922:

OP setting should be set to the segment 20.4 cm.

[OFS] = 7.0 cm

▶ [OP] is to be set to 20.4 cm + 7.0 cm = 27.4 cm.

9.7.5 Calculation aids [OP]

For proper functioning of the overflow prevention OP the minimum distance (y) must be observed: Notes on installation instructions for the operation with overflow prevention ( → 11)

The following correlations apply:

B + c = L + u and B = z + y	B: Tank height	L: Probe length
	c: Outside length	u: Distance between probe and tank bottom
	y: Required response level OP from above. Minimum: Notes on installation instructions for the operation with overflow prevention (→ ☐ 11) Maximum: Setting values for [OP] (→ ☐ 28)	z: Required response level OP from the bottom (maximum: z < L - c - y or z < B - y).

9.7.5.1 Definition"from the cover"

Required distance (y) of the overflow prevention OP "from the cover" is defined.

• Without offset ([OFS] = [0]): [OP] = L - c - y
- With offset ([OFS] = u): [OP] = L - c - y + u or [OP] = B - y

Example LTx922:

c = 3.0 cm, y = 5.0 cm, u = 1.0 cm

Without offset:

[OP] = 26.4 cm - 3.0 cm - 5.0 cm = 18.4 cm

With offset:

[OP] = 26.4 cm - 3.0 cm - 5.0 cm + 1.0 cm = 19.4 cm

9.7.5.2 Definition"from the bottom"

Response level (z) of the overflow prevention OP from the tank bottom is defined.

• Without offset ([OFS] = [0]): [OP] = z - u
• With offset ([OFS] = u): [OP] = z

Example LTx922:

z = 18.0 cm (from the tank bottom), u = 1.0 cm

Without offset: [OP] = 18.0 cm - 1.0 cm = 17.0 cm

With offset: [OP] = 18.0 cm

▶ Round the calculated value to the next lower adjustable value: → Setting values for [OP].

10 Operation

After power on, the unit is in the RUN mode (= normal operating mode). It carries out its measurement and evaluation functions and generates output signals according to the set parameters.

▶ Check whether the unit operates correctly.

10.1 Operating indicators

[---] continuous	Initialisation phase after power on
Numerical value + LED 1	Current level in cm.
Numerical value + LED 3	Current temperature in °C
LED 5...8	Switching status OUT1... OUT4 (lights when the respective output is switched).
[UL]	Warning: temperature below approx. -30 °C.
[OL]	Warning: temperature exceeding approx. +100 °C.
[----]	Level below the active zone.
[FULL] + [numerical value] alternately	The overflow prevention OP is reached (overflow warning) or the level is above the active zone.
[≡≡≡]	Adjustment [cOP] of the overflow prevention OP necessary.
[Loc]	Unit locked via operating keys; parameter setting impossible. For unlocking press the two setting buttons for 10 s.
[uLoc]	Unit is unlocked / parameter setting is possible again.
[C. Loc]	The unit is temporarily locked. Parameter setting via IO-Link is active (temporary locking).
[S. Loc]	Unit is permanently locked via software. This locking can only be removed with a parameter setting software.

10.2 Display the set parameters

▶ Briefly press [Mode/Enter] (if required, repeat several times).
▷ Menu structure is scrolled until the required parameter has been reached.
▶ Briefly press [Set].
▷ Respective parameter value is displayed for 30 s.

10.3 Read / reset extreme value memory temperature

▶ Select parameter [Lo. T] or [Hi. T]
▶ Briefly press [Set] for reading.
▷ Device displays the stored maximum or minimum value for 30 s.
▶ To delete the memory keep [Set] pressed until [----] is displayed.
▶ Briefly press [Mode/Enter].

10.4 Fast selection level / temperature

In the operating mode:

▶ Briefly press [Set].
▷ Display of the other process value for 30 s, the respective LED is lit.

10.5 Error indications

Indication	Possible cause	Recommended actions
[Err]	Fault in the electronics.	► Replace the unit.
[SEnS]	Interfering sources (e.g. EMC)Faulty wiring Supply voltage disturbed	► Check electrical connection.► Check connection between the sensor and the tank ground.
[FAIL]	Error during adjustment of the overflow prevention OP:Overflow prevention covered by the medium during adjustment. Overflow prevention soiled. Minimum distances too small. Mounting element detected below the overflow prevention. Measured value not constant.	► Lower the level, if possible. Clean the probe. Observe the notes on installation. ▶ Correct the position of the overflow prevention OP. Repeat the adjustment. Deactivate OP.
[cr. UL]	Error: temperature below approx. -40 °C.	► Check process temperature and correct, if necessary.
[cr. OL]	Error: temperature exceeding approx. +125 °C.	► Check process temperature and correct, if necessary.
[SCx] + LED 5...8	Flashing: short circuit in switching output x.	► Remove the short circuit.
[SC] + LED 5...8	Flashing: short circuit in all switching outputs.	► Remove the short circuit.
[PARA]	Faulty data set.	► Reset to factory settings [rES].

10.6 Output response in different operating states

	OUT1/2	OUT3/4*
Initialisation phase	OFF	Off
Overflow prevention OP not adjusted.	OFF	Off
Overflow prevention OP adjusted or deactivated, normal operation,	according to process value and setting [oux]
Fault	According to setting [FOUx]

11 Maintenance, cleaning, change of medium

When removing or installing the unit for maintenance and cleaning:

▶ Make sure that the stainless steel tube clip is fixed to the sensor.
▷ It must be possible to exactly reproduce the installation height and position.

▶ Remove the sensor and clean it / carry out maintenance

▶ Install sensor exactly in the same position as before. Otherwise check the parameter [OP] and carry out [cOP] once again.

11.1 Maintenance information for the operation without overflow prevention

[MEdl] = [Auto] or [OP] = [OFF] (overflow prevention OP deactivated!)

The unit must be reinitialised in the following cases (switch the operating voltage briefly off and on again):

• After all maintenance operations.
• After cleaning operations (e.g. water jet cleaning of the sensor probe).
- If the sensor was removed from the tank and then installed again during operation.
- If the active zone of the sensor was touched with the hand or grounded objects (e.g. a screwdriver, a cleaning lance).
- If the connection between the sensor and the tank wall / counter-electrode was changed.
- After a change of the medium with considerably differing dielectric constants. For manual selection of media, first the [MEdI] setting needs to be adjusted.

12 Applications

12.1 Storage tank

Level control and min / max monitoring with 4 switching outputs.

(No temperature monitoring; [SEL3] and [SEL4] = [LEVL]).

Replaces 4 float switches.

Configuration of the switching outputs 1...4.
SP1	Maximum value exceeded → Alarm.
OU1	Hysteresis function, normally closed (Hnc).
SP2	Upper preset value exceeded, finish → Refilling.
OU2	Hysteresis function, normally open (Hno).
SP3	Below lower preset value, start → Refilling.
OU3	Hysteresis function, normally closed (Hnc).
SP4	Below min. value → Alarm.
OU4	Hysteresis function, normally open (Hno).
rP1...rP4	Each slightly below SPx to suppress wave movements (factory setting).

XX. X: Display value

• If the level is below SP1, the output is switched. If the level is above SP1 or if there is a wire break, output 1 switches OFF (alarm message "overflow / wire break").
• If the level reaches SP2, output 2 signals (upper preset value reached; finish refilling).
• If the level is below SP3, output 3 signals (below lower preset value; start refilling).
• If the level is above SP4, the output is switched. If the level is below SP4 or if there is a wire break, output 4 switches OFF (alarm message "below min. value / wire break").

12.2 Pumping station

Empty the tank / overflow prevention with 3 switching outputs.

Output OUT4 can be used for temperature monitoring:

[SEL3] = [LEVL], [SEL4] = [TEMP]

Replaces 3 float switches and 1 temperature switch.

Configuration of the switching outputs 1...3.

SP1	Maximum value exceeded → Alarm.
OU1	Hysteresis function, normally closed (Hnc).
SP2	Upper value exceeded → Submersible pump ON.
OU2	Hysteresis function, normally open (Hno).
SP3	Lower value reached → Submersible pump OFF.
OU3	Hysteresis function, normally closed (Hnc).
rP1...rP3	Each slightly below SPx to suppress wave movements (= factory setting).

XX. X: Display value

A: Empty the tank.

B: Overflow prevention

• If the level is below SP1, the output is switched. If the level is above SP1 or if there is a wire break, output 1 switches OFF (alarm message "overflow / wire break").
• If the level exceeds SP2, output 2 signals (upper value exceeded; submersible pump ON).
• If the level is below SP3, output 3 signals (lower value reached; submersible pump OFF).
• Suggestion for temperature monitoring:

ou4 = Hnc

SP 4 = 4 5 (^ ° C)

rP4 = 4 0 (^ ° C)

As long as the temperature is below SP4, the output is switched. If the level is above SP4 or if there is a wire break, output 4 switches OFF (alarm message "overtemperature / wire break").

13 Factory setting

	Factory setting			User settings
	LT8922	LT8923	LT8924
SP1	10.0 (cm)	19.5 (cm)	29 (cm)
rP1	9.5 (cm)	19.0 (cm)	28 (cm)
SP2	6.0 (cm)	10.0 (cm)	15 (cm)
rP2	5.5 (cm)	9.5 (cm)	14 (cm)
OP	20.4 (cm)	40.7 (cm)	61 (cm)
SP3	65 (°C)
rP3	62 (°C)
SP4	70 (°C)
rP4	67 (°C)
MEdI	OIL.2
cOP	----
rES	----
ou1...4	Hno
dS1...4	0.0
dr1...4	0.0
P-n	PnP
Lo. T	----
Hi. T	----
OFS	0
FOU1...4	OFF
SEL3	TEMP
SEL4	TEMP
SELd	LEVL
diS	O