Definition and purpose of the sensor

High-precision fuel level sensors (FLS, also meters or sensors) of the Escort brand are designed to determine the filling level of petroleum products in fuel tanks, reservoirs and storage tanks. The TD-150 meter (sensor) is used in transport technology as a fuel level meter, in industry - as a level meter for any light petroleum products. Escort FLS measurement type is capacitive. Its readings are based on the dielectric constant of the medium in which it operates; in this case, the medium is various types of light petroleum products (gasoline, diesel, kerosene, motor oil).

More detailed technical characteristics are presented in the technical data sheet of the device.

Basic terms and concepts

Fuel level sensor (FLS) - device which is used for measuring fuel level.

Serial number - code consisting of letters and numbers assigned to a device (sensor).

CNT - an oscillatory circuit, thanks to which the basic level of filling of the sensor measuring tubes with fuel is calculated. This level is converted to a final value determined by the data interface.

Data transfer protocol - a set of specific logical-level rules or conventions that govern the exchange of data between different programs or devices. For TD-150, the main transmission protocol is LLS via the RS-485 interface.

Data transfer mode - this is a type of boundary between two objects or nodes, which are regulated by a special accepted standard and implemented using established methods, tools and rules. TD-150 has the following operating modes:

RS-485 (Passive and Active)
Analog
Frequency

Interface - a physical connection method and/or a set of software tools that allows data to be transferred between two or more devices.

RS-485 - digital data transmission mode. The sensor waits for a corresponding request from the receiving device. Works using the LLS protocol. Based on CNT, a value is generated in conventional units of the selected range (1-1023 units or 1-4095 units)

Converter - digital converter RS-485 to USB (С200М или С200М2) for configuring wired sensors.

Active (periodic) RS-485 - operating mode in which the sensor, without waiting for a request from the receiver, itself transmits packets with command data within 2 seconds.

Analog - mode in which a corresponding voltage is generated based on the CNT in the approximate range of 0.2-9V.

Frequency - mode in which the corresponding frequency in Hz is generated based on the CNT (301-1323 Hz with a value range of 1-1023; 301-4395 Hz with a value range of 1-4095).

Navigation terminal - the main element of the system for monitoring the operation of transportation carried out by means of satellite communication. Without it, it is impossible to control transportation, to determine the coordinates of the vehicle location. It collects information from sensors and on-board system of the vehicle, and then transmits it to the device/server, which belong to the controlling specialist.

Preparation

Preparing the Tank

To prepare the tank you should:

Empty the tank, clean and dry if necessary
Remove fuel vapors and air from the tank (especially for a gasoline tank, but in the case of a diesel engine, this procedure should not be neglected, since gasoline could be added to the diesel); to do this, you can heat water to boiling point and direct the resulting steam into the tank or use carbon dioxide so that it displaces fuel vapors and air; ensure that any open flame sources are sufficiently far away from the fuel tank
Find the geometric center of the tank and drill a hole in it using a ø3mm drill bit. Then, using a piece of stiff wire, examine the tank for the presence of partitions in it
Choosing a location for installing the FLS
Drilling the tank and subsequent examination of the tank for the presence of partitions
Drilling a hole at an angle
Removing a Drilled Disc
If the space inside the tank in the selected location is free, drill a ø 35 mm hole using a bimetallic bit; When drilling, keep the bit tilted slightly to prevent the cut section from falling into the tank. Use a magnet to catch chips and prevent them from getting into the tank.
If it is impossible to install the sensor in the geometric center of the tank, try choosing another location as close as possible to the geometric center of the tank; this point should coincide with the place where the height of the tank is maximum. This way you reduce the risk and amplitude of level fluctuations associated with fuel movement while driving.

Why should the sensor be mounted in the geometric center of the tank?

The highest point must be chosen so that the sensor can measure the level of all the fuel inside the tank without any blind spots.

The fuel level readings from a sensor installed in the center of the tank will be least affected by movement and fuel overflow in the tank.

If it is not possible to install the sensor in the center of the tank, consider installing two sensors diagonally at two corners. When fuel flows to one side of the tank, the level on the corresponding sensor will rise, and on the opposite side, the level will correspondingly decrease, while the average level will remain unchanged.

Video example of the importance of installing the sensor at the geometric center of the tank.

Attention: Before starting the calibration, the vehicle/fuel tank must be positioned flat in relation to the horizon, i.e. on a level surface without a slope.

If the tank has an irregular geometric shape, the sensor must be installed at the maximum depth of the tank, closer to the geometric center.

When installation in the center is impossible - two or more FLS.

To increase accuracy and reduce level fluctuations, install two sensors in one tank. This solution is mainly used in tanks with a capacity of more than 600 liters and having a length of 1500 mm. Sensors must not be installed close to the walls of the tank.

Also, two or more sensors should be installed if it is not possible to install the sensor in the center of the tank and (or) the tank has an elongated shape, i.e. The length of the tank is significantly greater than its height.

Note. Installing a single sensor in an elongated tank will allow you to detect drains and refills. But increased level fluctuations while driving may not allow the monitoring platform to correctly read fuel consumption. Therefore, installing two sensors is preferable.

Preparing the sensor

Preparing the sensor tubes

Before calibrating the sensor, you should determine the future length of the measuring tubes in accordance with the height of the tank and cut or extend them. The length of the tubes should be calculated according to the following formula:

L = H - 15 mm,

where L - tubes length after changing the length

and

H - height of the tank at the installation point.

ATTENTION!!! The minimum length of the tubes should not be less than 15 cm (150 mm). Otherwise, it will most likely not be possible to obtain adequate graphics. The maximum length of the tubes can reach 6m.

Use a hacksaw to cut the tubes. When sawing, be careful not to damage the connection of the tubes to the circuit board inside the sensor head and to prevent metal shavings from falling into the tubes.

Avoid getting shavings inside the tubes - this may lead to a short circuit in the sensor; if this happens, blow the tubes with compressed air through the drainage holes under the sensor flange. Sand the edges of the tubes with sandpaper to remove any burrs or irregularities.

To extend sensor tubing, use a collet extension and an additional tube.

Inner nuts (yellow elements) are used to connect the inner tubes. Once they are installed and the studs are screwed into them, the tubes do not have to touch each other, but try to get them as close to each other as possible.

**Internal connection of the collet connection**

The outer coupling and the corresponding nuts must be securely tightened. The outer tubes should touch each other.

Watch this video on our YouTube channel for a real-time overview of the connection.

Connection dimensions

Connection to the sensor, setup, calibration and calibration via the configurator on a PC

Installation of the configurator and connection to the sensor

The sensor can be configured using the configurator on a PC (From here onwards- "configurator").

Connect the sensor to the USB-RS-485 converter using a 6-pin MOLEX connector or using cable clamps if a cable route is connected to the sensor. Orange wire is line A of the RS-485 sensor interface, white wire is line B of the RS-485 sensor interface, black wire is GND, red is PWR.

We recommend using our Escort C200M/C200M2 USB-RS-485 converter, since we cannot guarantee 100% compatibility of our devices with converters from other brands.

When working with a laptop, we recommend connecting it to the power supply and/or connecting an additional USB cable to the ADD connector of the PWR C200M. Otherwise, there may not be enough power to operate the sensor and transmitter.

Along with installing the configurator 1.0.2.38, the drivers for the C200M will be installed automatically.

If you use C200M2 on Windows 10 and 11 operating systems, drivers should be installed automatically from Windows Update, on the Windows 7 operating system and below, you may need to disable the electronic signature of drivers and manually install drivers for the С200M2.

If the driver was installed correctly, then after connecting the converter to your PC/laptop, you will see the STMicroelectronics Virtual COM Port (1)(C200M) or USB-SERIAL CH341A (2)(C200M2) device in the COM and LPT ports section of the Windows device manager " to enter this menu, press win+r and enter devmgmt.msc and press OK (3) and then expand the com ports submenu (4)"

The com port number displayed in this menu is also needed to connect the sensor.

After connecting the converter, sensor to it and checking the installation of drivers by checking the com port number of the converter, you need to open the configurator, select the desired com port which we could find in the device manager (1) and press the FLS button (2).

The connection to the FLS should be made within 15 seconds after the sensor has been connected to power, if the sensor operating mode has been changed from RS-485 to any other.

After connecting the sensor you should see this menu:

Sensor serial number
Sensor firmware version (FW)
Sensor temperature
Current sensor level
Current CNT level (raw level value) of the sensor
LLS network addresses connected to this converter (if there is more than one address in this list, it means either more than one sensor is connected to the line at the same time or there is interference on the line, in this case it is necessary to check the connection to the FLS for the presence of other conflicting devices and it is necessary to close other programs using the com ports for example tracker configurator)
Network address of the polled sensor (This address is used when connecting in RS485 mode)
Current sensor operating mode
Current range of output values (1-1023 or 1-4095)
Current filtration type and degree
Connected sensor model

Sensor calibration

After you have lengthened or shortened the sensor tubes, you need to carry out the sensor calibration procedure.

To do this you need:

Go to menu "Sensor calibration"

Insert the centralizer into the tubes
Fill the tubes with fuel (by sealing the drain holes with duct tape and filling the tubes, turning the sensor upside down, or submerging the sensor tubes completely in fuel)
Wait for the CNT level to stabilize (1)
Deselect the "Calibration without fuel" slider (2)
Click "Full" (3)
The value "Full" (4) should change to a value close to the value of the current CNT (1), but not equal to it, since this value is set according to the temperature compensation of the sensor

Closing the drain holes, inverting the sensor and filling the tubes with fuel
Filling the tubes by immersing the sensor in fuel (drain holes open)

Empty the pipes of fuel, leave the centralizer in the pipes
Wait for CNT to stabilize (1)
Click "Empty" (2)
The value "Empty" (3) should change to a value close to the value of the current CNT (1), but not equal to it, since this value is set according to the temperature compensation of the sensor
Click "OK"

The sensor level should display as 1, the sensor calibration process is complete.

Thus, CNT should increase as the sensor tubes fill with fuel. It should change from a value close to the Empty calibration value to the Full calibration value.

ATTENTION! UNBLOCK THE DRAINAGE HOLES AFTER CALIBRATION!!!

Calibration without fuel

An alternative calibration option is calibration without fuel.

In this case, make sure that the sensor tubes are empty and free of fuel, but the centralizer must be inserted into the tubes. Leave the "Calibrate without fuel" switch (1) active (green) and press "Calibrate" (2) . The values above the Empty and Full buttons will change automatically.

If you calibrate the sensor without fuel, the operating range may change slightly.

Initially there are two measurement ranges:

From 1 to1023
From 1 to 4095

The sensor never sends a value of 0. If there is no fuel, level 1 is displayed.

When calibrating without fuel, since the sensor does not know what fuel will be used, the "Empty" value is set based on the current (CNT), the "Full" value is set by a formula and, depending on the length of the tubes and the final fuel used, the range may change .

For example, when the tank is full, the sensor will show 3843 instead of 4095, or it is possible that when the tank is 98% full, the sensor will already display the value 4095.

We recommend, if possible, calibration with fuel.

Setting the calibration value Full and Empty manually

We do not recommend using this functionality, but you can set the Full and Empty calibration values manually to save time when you are using sensors of the same length in the same tanks.

Attention!!! Setting calibration values manually will most likely increase the sensor error! We do not recommend doing this!

To do this, enter the Full and Empty calibration values of the previously calibrated sensor into the appropriate fields in the configurator.

Setting the mode, range and network address

Setting the mode

In the main menu, you can change the operating mode of the sensor. The name of the mode coincides with the interface that is used to physically connect the sensor to the GPS terminal

Select the mode you need(1) and click “Save parameters to device”(2)

- Passive RS485 should be selected when you plan to connect to line A and B of the terminal's RS-485 interface. The terminal must have the function of polling sensors, for example, requesting information from them. The terminal must be able to interrogate sensors in accordance with the LLS protocol.

- Frequency mode is used when connecting to a GPS terminal to inputs that can receive and read signals in the range 300 Hz … 1323 Hz or 300 Hz … 4395 Hz.

- Active RS485 mode should be used if the terminal has an RS-485 connection interface, but cannot independently poll the sensor, for example, request information from it; the sensor will send its readings independently every 2 seconds.

Note: The analog output of the TD-150 is always active on the green wire in the 0.2-9V range, there is no need to turn it on separately

Setting the range

If you are configuring the sensor to operate in RS-485, Active RS-485, or Frequency modes, you can select the range 1-1023 or 1-4095 (1) . In frequency mode, the range will be from 300Hz to 1323Hz or 300Hz to 4395Hz.

After changing the range, click “Save the parameters to device” (2).

The range 1-1023 is most often used for sensors that are shorter than 1 meter. However, if we are talking about a stationary tank, the height of which is small, but the length and width are more than 2-3 m, it is better to choose the range 1-4095.

Setting the network address

The default network address of the sensor is 1; if more than one unit is installed or other LLS devices are added, the network address on the sensor may need to be changed. The network address of each sensor must also be specified in the settings of the receiving device (navigation terminal).

Attention!!! There cannot be two devices with the same network address on the same line; this will cause a conflict.

To change the network address, enter a new address in the range 0-255 in the “Change network address” field (1) and click “Save the parameters to device” (2), after which the configurator should switch to the new sensor address and display the new sensor address in the field "Available units" (3) and "Poll network address" (4).

Tank calibration

Once the length sensor has been adjusted to the height of the tank and the sensor has been calibrated, you need to install it in the tank.

Install the sensor into the tank of the installed tube in the previously drilled hole ø 30-35 mm. Make sure the gasket is installed between the sensor and the tank. After this, screw the screws from the installation kit into the previously drilled ø 3mm holes.

Installing the sensor inside the tank
Screwing the self-tapping screws

Proceed to tank calibration. This procedure will result in a "level-liters" (or "level-gallons") table that will allow your monitoring platform to convert the level values that the sensor provides into liters/gallons that are displayed in the monitoring platform reports.

In order to create such a table, you need to fill the tank by step by step adding fuel to the tank batch by batch and recording level-liter(/gallon) pairs after each batch using the Tare menu in the application.

Suppose you need to tare a 100L tank in ten 10L portions.

To do this you should:

Connect sensor
Make sure that the filtration is set to “No” (1). Filtration slows down the level calculation and can increase the tank calibration time.
Create an Excel table. Save it in .csv format. The first row of the table should look like this:
You can also create a text file on your PC/Phone or manually record calibration
Select whether calibration is performed by filling or draining. The Filling method is recommended as it is more accurate. If you select the Drain method, you cannot be sure what exact amount of fuel is in the tank and whether the tank is full or not.
Select portion size

ATTENTION! Portion volume is not the number of portions! This is the number of liters/gallons in each portion! In the example below, the tank supposedly contains 100 liters and this volume can be divided into 10 portions of 10 liters. If the volume of the tank was 300L and it needed to be divided into 10 portions, the portion size would be 30L.

Start calibrating the tank by pouring portions into the tank or emptying the tank for a given portion and recording the level in the table after it has stabilized

An example of calibration by filling in portions of 10 liters and imagine that in this case there are 10 liters in the tank that cannot be removed and when the sensor is placed in the tank it immediately shows the value 115 instead of 1.

You add the first portion of fuel to the tank. The level should change from 115 to some other value. If the level does not change, check the sensor drain holes. They may be blocked by electrical tape, which must be removed after the sensor has been calibrated. If the holes are blocked, the air inside the tubes will prevent fuel from getting inside the tubes.

Next, add the following row to your table.

Continue this until the tank is full.

However, if there are bends or other irregularities in the shape of the tank, the volume of fuel portions should be reduced until the fuel level is above the irregularly shaped section of the tank. After overcoming such a section, you should return to the original portion volume.

Assume that you do the tank calibration in portions of 10 liters as before. The level rises to an area with a complex shape.

You reduce the serving size from 10 to 5 liters. And continue adding portions until you overcome the area with a complex shape.

When the level is above the problem area, you can return to the original serving volume of 10 liters.

Once the tank is full, you will have a calibration chart like the following example.

**Table for a tank that cannot be filled 100%**

If in your case the level does not reach 1023 or 4095 because the tank cannot be filled completely, do not worry about it. It is acceptable that your table would end up like the following example, even though the sensor range is 1-1023.

The number of servings depends on the capacity of the tank. See the table with our recommendations below.

Recommended number and portion size for calibrating the tank
Tank volume	Number of portions	Volume of each portion (Tank Volume / Number of portions)
0-60	10-20	3-4
61-100	12-20	5
101-500	10-50	10
501-1000	20-50	20
Over1000	As per your capabilities. The rule of thumb is that the larger the portions and smaller the volume, the more accurate the data will be

The rule of thumb: more portions means more accurate reports on the monitoring platform.

You can create a table on your platform by loading it from a file or by entering values manually.

Tilted tank calibration with 2 FLSs

If it is not possible to level the car/tank with respect to the horizon, you can calibrate it in the tilted position of the tank.

Technically, this kind of calibration is no different from the usual one: you pour a portion of fuel into the tank, wait for the level to stabilize, fix it, and fill in the next portion.

However, the details of such calibration are much more important, so the algorithm of actions should be as follows:

Pour portions of fuel into the tank until the fuel level reaches the measuring tubes of the second FLS, which is located higher due to the inclination.
When the second sensor reaches the fuel level, reduce the size of the poured portion by half. IMPORTANT: it is necessary to reduce the portion only in the calibration tables for both FLS; the actual volume of the portion being filled remains unchanged.
Once the tubes of the sensor located lower down are completely immersed in fuel, the calibration of this FLS is considered complete.
However, before continuing calibration of the second FLS, it is necessary to return the nominal portion volume to the original (i.e. double it). IMPORTANT: The actual portion size still remains unchanged until the tank is finally filled and the calibration process is completed.

Thus, the resulting calculation tables (calibration tables) will be adequately accepted by the monitoring platform if a third FLS (virtual) is created in it, which is the sum of two real FLS.

Calibration of a tank whose height varies along its length

This method of calibration is in many ways similar to that presented in the previous part.

The algorithm of actions is as follows:

Pour portions of fuel into the tank until the fuel level reaches the measuring tubes of the second FLS, which is located higher due to the difference in height.
When the second sensor reaches the fuel level, reduce the size of the poured portion by half. IMPORTANT: it is necessary to reduce the portion only in the calibration tables for both FLS; the actual volume of the portion being filled remains unchanged.
Continue calibrating in this manner until the tank is full.

Thus, the resulting calculation tables (calibration tables) will be adequately accepted by the monitoring platform if a third FLS (virtual) is created in it, which is the sum of two real FLS.

Filtration

After tank calibration is completed, select the required “Filtration level” and click “Save the parameters to device”

Below are recommendations for choosing the filtration level for different types of vehicles:

Recommended filtration level for wired FLS

0-1	Stationary units
2-6	Vehicles on high or medium quality roads
7-12	Agricultural machinery units
13-15	Heavy-duty machinery

General tips for installing filtration:

If the length of the tubes is less than 30 cm, the filtration level must be set higher than usual
The closer the sensor is to the tank walls, the higher the filtration is
The worse the road surface, the higher the filtration
You only need to set the median filter type
Example before enabling filtering and after.

Setting and removing a password

If necessary, you can set a password on the sensor to change settings.

To do this:

Click on the "Service" button (1) and then "Security" (2)
In the menu that opens, you can enter a password consisting of numbers and then click set password. Also note that the password cannot start with 0.
After successfully setting the password, a red lock should appear next to the FLS icon

PLEASE NOTE THAT THE PASSWORD RESET PROCEDURE CAN BE VERY TIME-CONSUMING. WE RECOMMEND THAT YOU TAKE A RESPONSIBLE APPROACH IN SETTING YOUR PASSWORD AND SAVING IT.

To change the settings of a password-protected sensor or remove a password, you need to perform the password removal procedure

Click on the "Service" button (1) and then "Security" (2)
In the menu that opens, enter your password (or if you have lost your password, the master password provided by technical support) and click "Remove password"
If the password was successfully removed, the lock should turn green

Attention! By default, there is no password set on the sensor! If you connected the sensor and a password was already set on it, contact technical support.

Connection to the sensor, setup, calibration and calibration via a mobile application on Android

Connection to the sensor

Wired sensors can be connected to a smartphone to the Escort Configurator app. For this you will need:

Smartphone running Android operating system with OTG technology support
RS-485 - USB converter, for example, Escort C200m2
USB-OTG adapter for connecting the converter to a smartphone

Attention! You cannot update the FW of the sensor through an application on a smartphone; this can only be done using a computer and the Bootloader program

By connecting the sensor to your smartphone you can:

calibrate the sensor
change filtering level
change network address
select the sensor operating mode
select measurement range (1023 or 4095)
set or change password
calibrate the tank

Connect the sensor to your smartphone according to the diagram
Check that the converter is turned on (there is a power indication), on some models the OTG mode must be enabled manually in the phone settings
Example of enabling OTG mode on OPPO smartphones
Select the RS-485 tab (1)
Select Fuel level sensor (2)

When connecting for the first time, the phone should ask for access to the converter, click OK

If such a request does not appear and the sensor is not detected, try connecting additional power to the sensor according to the connection diagram, also check that the power indication on the converter is active and that the OTG mode is enabled on the smartphone
If, after asking for permission, you receive the error “Unable to connect the device,” this is normal. Just select the fuel level sensor again.
Error failed to connect device after requesting permission
If you are using a C200M inverter, you can connect an additional power supply to the inverter. To do this, you need to take a power supply for charging your smartphone with a microUSB connector and connect it to the C200M using the ADD PWR connector
Once connected successfully, you will see the main screen of the sensor.

Sensor serial number
Sensor firmware version (FW)
Sensor temperature
Network address of the polled sensor (This address is used when connecting in RS485 mode)
Current sensor operating mode
Current filtration type and level
Current sensor level
Connected sensor model