UM0526
User manual
STEVAL-IFS007V1 4-channel
proximity sensor board based on TDA0161
Introduction
This user manual explains the STEVAL-IFS007VA which has been designed to be easy to
plug into 24 V operated systems as it is usually implemented in factory automation
environments.
The document shows the STEVAL-IFS007V1 demonstration kit (hereafter also called “proxy
board”) features, its technical characteristics and then, as an optional feature, the
connectivity to the CLT3-4BT6 board (a board hosting a current-limited overvoltage-
protected quad digital termination). Finally, a detailed illustration of an application example is
also given. The STEVAL-IFS007V1 can be considered a system end-board. It could be
placed as a standalone in systems where no processing or control characteristics are
required or it could be integrated as an end board in control systems, in which case an
interface board like the CLT3-4BT6 previously mentioned is necessary to protect the
microcontroller and other application specific devices from high current and voltages out of
their specifications. When the board is used as a standalone, it is possible to connect up to
4 different and independent coils. Each coil acts as the passive element able to sense an
incoming metallic object by sensing variations in high frequency eddy current losses. The
TDA0161 proximity detector changes its output signal as a consequence of a supply current
change. In fact, independently of the supply voltage provided, this current is high (or low)
according to the presence (or absence) of a closely located metallic object, consequently
the output voltage level corresponding to that channel changes coherently. In terms of
output voltage, the variation is between ~8.5 V and 11.5 V in a 24 V supplied system, so the
output span is about 3 V. On-board jumpers are placed in order to enable/disable channels.
Also on-board LEDs are placed to furnish a local alert when an object is close to a coil. At
this end, the circuit parameters are tuned in order to detect metallic objects at a distance up
to 4 mm. For further details on parameter tuning and on the circuit and device functionality,
please refer to the TDA0161 device datasheet.
Figure 1.
The STEVAL-IFS007V1 board
March 2008
Rev 1
1/9
www.st.com
Contents
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Contents
1
The proxy board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1
1.2
The coil support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
The CLT3-4BT6 board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2
Proxy board application example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1
Application description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3
4
Board schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
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List of figures
List of figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
The STEVAL-IFS007V1 board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
STEVAL-IFS007V1 layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Design of the plaque with the physical dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
The CLT3-4BT6 board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
The boards used in the application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Application example using two STEVAL-IFS007V1 boards and the related auxiliary
boards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
The STEVAL-IFS007V1 schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
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The proxy board
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1
The proxy board
This board could be considered the end board of control systems commonly used in factory
automation environments. The board also offers a connector that allows interfacing it with
other 24 V supplied systems or systems like the CLT3-4BT6 board for IO protection in order
to connect it to control boards typically running at 3.3 V or 5 V. A plaque for mounting the
sensing element at distances up to 2 m (look forward for details) can be taken into
consideration in systems using the STEVAL-IFS007V1. The main features are as follows:
●
Four TDA0161 proximity detectors, able to detect the current losses in the passive coils
connected to the STEVAL-IFS007V1 board. They act as oscillators and integrate the
sensing part constituted of the coil (typically 330 µH, 0.54 A standard coil) and an
external conditioning circuitry useful to adjust the detection distance
Each proximity detector is powered by a common 24 V supply
●
The layout of the STEVAL-IFS007V1 board is shown below.
Figure 2.
STEVAL-IFS007V1 layout
1.1
The coil support
Figure 3
shows an example of a physical support able to host the coil. This could be done
for the remote positioning of the sensing elements (the 2 square holes are useful to fix the
plaque to external supports, walls, etc.).
Figure 3.
Design of the plaque with the physical dimensions
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Proxy board application example
1.2
The CLT3-4BT6 board
The current limited termination demonstration board is a quad input/output digital
termination interface designed for 24 Vdc automation applications. It achieves the front-end
circuitry of a digital input module (IO) in industrial automation environments.
This board is made of a parallel input voltage protection, a serial input-output current limiting
circuit, and an opto-coupler driver. Each channel circuit terminates the connection between
the logic input and the associated high side sensor (2-3 wire sensors) or switch.
Figure 4.
The CLT3-4BT6 board
2
Proxy board application example
This chapter describes a system integrating the proxy board, the CLT34BT6 board
previously described, and a control board that allows communication through a CAN
(Controller Area Network) network, for example in industrial environments. The system can
be intended for local and remote alert applications in distributed control environments
needing a robust communication protocol like CAN. The mentioned control board (on the
right side of
Figure 5)
must function as a collector of signals coming from the interface board
CLT3-4BT6, able to perform local alert through LED on/off, and remote alert when
connected to other control boards communicating with the CAN protocol with same
parameters. The board depicted in grey and called power supply board can be optionally
part of the system, especially if only the 24 V power source is present.
Figure 5
below
identifies the four main blocks of the system.
Figure 5.
The boards used in the application
24 V
24 V
up to 4 independent
passive detectors
(coils)
5V
CAN
network
@ 500 KBps
Control board
5V
…
x4
x4
CLT3-4BT6
STEVAL-IFS007V1
24 V input
Power-Supply board
5 V output
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