RU2573391C2 - Control system - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: invention relates to a control system for use in underground operations having two control computers and one network cable which connects control computers. The control computers are designed to transmit data over a first network cable using high-frequency signals. Each control computer is designed to transmit data using low-frequency signals over one network cable.

EFFECT: improved transmission.

10 cl, 11 dwg

Description

The present invention relates to a control system for use in underground mining with at least two control computers and at least one network cable connecting the control computers. Control computers are designed to transmit data on the first wire of a network cable through high-frequency signals.

Control systems of this type are known in principle and are used, for example, in underground mining, in particular in explosive areas. When used in hazardous areas, the currents and voltages used must be selected in such a way as not to generate enough energy for the explosion.

In known control systems, a plurality of control computers for controlling, for example, individual face shields are often installed in long chains. In this case, it is desirable to use network cables, such as Ethernet cables.

The task underlying the invention is such an improvement of the control system so that it is possible to efficiently use network cables.

This problem is solved using a control system with the characteristics of paragraph 1 of the claims and, in particular, due to the fact that each control computer, in addition, is configured to transmit data at least on the first wire of the network cable via low-frequency signals.

Thus, the network cable according to the invention is used repeatedly between control computers, for which data is transmitted via the network cable both in the high-frequency range, that is, for example, over 1 MHz, and in the low-frequency range, that is, for example, less than 1 MHz. Moreover, the data transmitted by means of high-frequency signals are independent of the data transmitted by means of low-frequency signals. Thus, for example, even with the loss of high-frequency signals, data transmission can continue through low-frequency signals.

According to the invention, high-frequency and low-frequency signals are transmitted on the same wire of a network cable. Thus, an improvement in the possibilities of using a network cable is not necessarily accompanied by an increase in the number of wires or, accordingly, the wires of the network cable. This makes it possible to further use the existing network cables.

Preferred embodiments of the invention are given in the description, drawings, as well as in the dependent claims.

According to a first preferred embodiment, high-frequency signals are supplied to a capacitively coupled network cable. For this, in control computers, a capacitive docking device can be provided that modulates high-frequency signals at least for transmission through the first wire of the network cable. For capacitive coupling, for example, a capacitor connected in series with a wire can be used, which can simultaneously serve as a high-pass filter to separate low-frequency signals from high-frequency ones.

According to another preferred embodiment, each control computer includes at least one transceiver and / or receiver for transmitting low-frequency signals connected to a network cable, in particular to resistive coupling. Thanks to the transceiver or receiver, low-frequency signals are modulated for transmission over a network cable and / or are received. Thus, by means of low-frequency signals, bidirectional communication is possible.

Due to the diverse input of high- and low-frequency signals through capacitive and resistive coupling, the mutual influence of high- and low-frequency signals can be prevented or significantly suppressed.

High-frequency signals can be generated according to the One-Pair-EtherNet (OPEN) -Standard standard. OPEN-Standard is a variant of the Ethernet standard that provides bidirectional data transmission at a speed of 100 Mbps using two wires. Using high-frequency signals of the OPEN-Standard standard, large volumes of data can be exchanged between control computers of the control system. In addition, with the help of the OPEN-Standard, the network topology currently being used can be determined (that is, the location of the connections between the control computers is established). If the topology is known, then high-frequency signals using the Virtual Local Area Network (Vlan) network can distribute addresses. Thus, each control computer of the control system can be targeted and provided with its address.

According to another preferred embodiment, an Ethernet switch is provided in each control computer. In this case, the Ethernet switch serves to supply data transmitted by high-frequency signals to the correspondingly correct control computer. The Ethernet switch recognizes whether certain data is intended for the control computer related to the Ethernet switch, and passes it on to the control computer.

According to another preferred embodiment, the low-frequency signals are an emergency-off signal and / or control signals for or from machines, such as, for example, time or position signals. Thus, by means of low-frequency signals, it is possible to realize an emergency shutdown, independent of the control computer software. This, in particular, is possible, since the emergency shutdown signal is not transmitted by means of high-frequency signals and therefore does not need preliminary processing by control computers. Instead, the emergency shutdown signal may be received directly by the transceiver or receiver. Thus, the emergency shutdown signal can be transmitted even if the computing unit of the control computer fails and can shut down machines connected to the control system. Thus, a reliable emergency shutdown is possible.

Similarly, regardless of the control computer software and high-frequency signals, low-frequency signals can transmit time-critical information, such as time or position signals. In this case, the time signals, for example, no longer need to be processed using the control computer software, so that delays depending on the loading of the control computer can be eliminated. Thus, machines connected to the control system can be controlled faster and more directly.

For the correct transmission of high-frequency signals between two control computers by means of low-frequency signals, redundant communication can also be carried out.

In addition, by means of low-frequency signals, for example, a time or position signal, i.e., for example, a roll position, or a plow installation, for example, can be transmitted to all control computers of the control system as a global message. Thus, at least basic information for controlling machines is available to all control computers, and this information can be supplied without using high-frequency signals.

Another possibility of using low-frequency signals is to determine the topology of the control system. For this, all control computers connected to the control system are first registered with low-frequency signals and then assigned addresses. In this case, address allocation can be done using a VLAN.

In addition, the invention relates to a control computer for a control system that has a physical interface that supplies high-frequency signals to the first wire of a capacitively coupled network cable. In addition, at least one transceiver and / or receiver is provided, connected to the first wire of the network cable, in particular with resistive coupling. The physical interface, also referred to as the PHY circuit element of the physical layer or the PHY semiconductor, may include, for example, a capacitor connected in series with the first wire of the network cable. As already mentioned above, in this case, the capacitor serves both for supplying high-frequency signals, and as a filter separating low-frequency signals from high-frequency ones.

In addition, the invention relates to a network cable for a control system containing exactly four wires. The first and second wires, in particular, are twisted together. The third and fourth wires have a correspondingly larger wire cross section than the first and second wires.

Alternatively, the first and / or second wire may also be twisted with the third and / or fourth wire. By twisting the wires, the transmission quality of the low and high frequency signals can be improved. In particular, with longer transmission lines, twisting and / or additionally provided shielding improve the quality of high-frequency signals in the first place.

The first and second wires can, in particular, be used for the simultaneous transmission of high and low frequency signals. They have a smaller wire cross-section and are therefore particularly suitable for data transmission in hazardous areas, since they can conduct only small currents and voltages and thereby fulfill the requirements for such areas.

The third and fourth wires can serve for power supply, for example, control computers, and, for example, the third wire conducts the supply voltage, and the fourth wire is the ground wire. In this case, the cross section of the third and fourth wires can be selected so that the components of the control system can be supplied with energy. The coordination of the power supply of the components of the control system can occur both through high-frequency signals according to the OPEN-Standard (that is, according to the Ethernet standard) and VLAN, as well as through low-frequency signals.

According to one preferred embodiment, the first and second wires are twisted together, the effective cross-sectional surface resulting from twisting approximately corresponds to the cross-section of the third and / or fourth wires. So, the strand from the first and second wires resulting from twisting can be the same thickness as the third and / or fourth wire. Thus, the network cable can be composed of three strands and have an almost identical, or correspondingly similar, thickness.

In addition, the invention relates to a plug for a network cable. The plug connector is characterized in that it is connected to the network cable by means of a single crimp, and, in addition, is made to electrically connect the network cable to the control computer. Typically, two crimps are required to connect the plug to the network cable. Thus, these costs according to the invention are reduced by half.

According to one preferred embodiment, the plug connector comprises one single housing element. Thanks to this, the plug connector can be manufactured and mounted in a simple and cheap way. In addition, the mechanical strength of the plug connector can be improved over conventional plug connectors with multiple enclosures.

Below the invention is purely described as an example based on possible embodiments with reference to the attached drawings, which schematically shows:

Figure 1 - control system according to the invention;

Figure 2 - control computer according to the invention;

Figure 3 is a sectional view of a plug connector in an uncompressed (a) and crimped (b) state according to the invention;

Figure 4 - six variants (a-f) of a network cable according to the invention;

Figure 5 is a cross-sectional view of a network cable in Figure 4e.

Figure 1 shows a control system 10 comprising a first control computer 12 and a second control computer 14 connected by a network cable 16.

The network cable 16 contains four wires, of which the first wire 18 and the second wire 2 0 are made twisted with each other. The third wire 22 conducts a supply voltage of 12 V. The ground wire is the fourth wire 24. The third and fourth wire 22, 24 are made with a larger wire cross section than the first and second wire 18, 20. In the illustrated embodiment, the cross section of the third and fourth wires 22 , 24 approximately twice the cross-section of the first and second wires 18, 20.

The first control computer 12 and the second control computer 114 are identical, and each of them contains one circuit element PHY 26. Each circuit element PHY 26 contains two outgoing wires, each of which is connected to the first output of two capacitors 28. The first wire 18 each control computer 12 is connected to the second output of the capacitors 28. Similarly, the second wire 20 is connected respectively to the remaining second output of the capacitors 28. Thus, the circuit elements PHY 26 first and osredstvom

the second wires 18, 20 can transmit high-frequency signals for which capacitors 2 8 are permeable. Moreover, the transmitted signals are made in the form of differential signals according to the Open-Standard standard.

In addition, each control computer 12, 14 comprises a first transceiver 30, as well as a second transceiver 32. The transceivers 30, 32 are connected through the resistor 34 to the second inputs of the capacitors 28, and thereby to the first wire 18 or the second wire 20. Resistors 34 chosen in such a way that the first and second wires 18, 20 are made with the same impedance, respectively, and thus, the transmission of high-frequency signals is not negatively affected.

The first transceiver 30 is designed as a bi-directional transceiver (BiDi - Transceiver), transmitting time signals and control commands for machines. A second transceiver 32 is provided for transmitting a shutdown alarm and is also configured as a bi-directional transceiver. The shutdown alarm in the illustrated example is transmitted through the first wire 18. A time signal is transmitted through the second wire 20. Thus, a separate wire is allocated for the shutdown alarm.

Figure 2 shows the internal device of the control computer 36, to which two network cables 16 are connected. Due to the possibility of connecting two network cables 16 from the chains of control computers 36 of arbitrary length to the control computer 36, control systems 10 can be assembled.

The control computer 36 inside is essentially symmetrically constructed and contains two PHY circuit elements 26, two first transceivers 30 and two second transceivers 32. The first and second transceivers 30, 32 are connected via resistors 34 to the first wires 18 or to the second wires 20 of the network cables 16 The circuit elements PHY 26 by means of capacitors 28 are connected to the first and second wires 18, 20 with capacitive coupling.

Power supply control computer 36 is carried out on the third wires 22 and the fourth grounded wires 24.

The PHY circuit elements 26 are connected to an Ethernet switch 38 of the network, analyzing the data received from the PHY circuit elements 2 6 and determining whether the received data is intended for the control computer 36. The data intended for the control computer 36 is transmitted further to the computing unit 40 , serving simultaneously as Media Access Control (MAC). In addition, the computing unit 40 is connected to the first transceivers 30 and the emergency shutdown unit 42. The emergency shutdown unit 42 may be activated, for example, by an emergency switch 44 provided in the input unit 46. The input unit 46 serves as a human machine interface (MMI) and is furthermore connected to the computing unit 40.

In addition, the control computer 36 includes a peripheral interface 48 connected to both the computing unit 40 and the emergency shutdown unit 42. Using peripheral interface 48, workflow 50 can be controlled, for example, by appropriately controlling (not shown) machines.

In the process, large amounts of data are transferred from the computing unit 40 to the Ethernet switch 38, which through the PHY 26 circuitry transmits this data in the form of high-frequency signals generated according to the OPEN-Standard, through the first and second wires 18, 20 of the network cable. Similarly, through the PHY 26 circuit elements and the Ethernet switch 38, data transmitted in accordance with the Open-Standard is received by neighboring control computers 36.

In addition, for example, time signals from the computing unit 40 are modulated for the second wire 20 by means of transceivers 30.

If the emergency switch 44 is operated, then this is recognized by the emergency shutdown unit 42, giving the second transceivers 32 a corresponding shutdown alarm. The second transceivers 32 through the first wires 18 transmit a shutdown alarm in the form of a low-frequency signal to neighboring control computers 36, which transmit it further to all control computers 36 of the control system 10.

If, in the opposite case, the shutdown alarm received through the first wire 18 is received and transmitted by the second transceivers 32 to the emergency shutdown unit 42, the latter notifies the computing unit 40 and the peripheral interface 48, as a result of which the machines connected to the peripheral interface 48 can stop immediately. In addition, the received shutdown alarm is transmitted further.

Figure 3a shows the plug connector 60 in an uncompressed state. The plug connector 60 comprises a one-piece metal housing element 62 into which a network cable 16 is inserted at one end (in the shown embodiment, on the right side). The network cable 16 passes through a crimp portion 64 of the housing element 62, in which the cavities 65 are provided.

At the front end of the network cable 16, four wires 18, 20, 22, 24 are provided with contacts, of which the first wire 18 and the second wire 20 are shown. All wires 18, 20, 22, 24 are connected respectively to the terminal 66. The connector 60 has a total of four pins 66, of which two are shown in FIGS. 3a and 3b. Contact pins 66 are located in two adjacent pairs.

Using the pin 66, the connector 60 can electrically connect the wires 18, 20, 22, 24 of the network cable 16 to the control computer.

Fig. 3b shows the plug connector 60 according to Fig. 3a after crimping, and as a result of crimping, the crimping portion 64 is compressed and thereby decreases in volume. As a result of crimping, the hollow spaces 65 are compressed and thus pressure is applied to the network cable 16, whereby the network cable 16 is connected to the plug connector 60 firmly and permanently.

On figa-4g depicts various options for the network cable 16, each of which contains exactly four wires 18, 20, 22, 24 and which can be connected, for example, control computers. All network cables 16 shown in FIGS. 4a-4g have a shield 68 mounted around four wires 18, 20, 22, 24 and formed, for example, by reinforcing network cables 16.

Figure 4a shows a network cable 16 with wires 18, 20, 22, 24 arranged parallel to each other and not twisted together.

The network cable 16 shown in Fig. 4b depicts the so-called stellar twist, in which all four wires 18, 20, 22, 24 are twisted, or twisted. If we consider the network cable 16 along the entire length, then approximately the first half of the length is twisted by rotation to the right, and the second half of the length is twisted by rotation to the left.

Fig. 4c shows another network cable 16, the second wire 20 and the third wire 22, as well as the first wire 22 and the fourth wire 24, respectively, twisted, or twisted, with each other.

The network cable 16 shown in Fig. 4d differs from the network cable 16 in Fig. 4 only in that the pairs of the second and third wires 20, 22, as well as the first and fourth wires 18, 24 are twisted together, respectively surrounded by an additional screen 68.

Network cable 16, already described with reference to FIG. 1, is shown in FIG. It contains twisted with each other, the first and second wire 18, 20, and also not twisted the third and fourth wire 22, 24. The third and fourth wire 22, 24 have a larger cross-section of the wire than the first and second wire 18, 22.

On Figg shows another network cable 16, the first wire 18 and the third wire 22, as well as the second wire 20 and the fourth wire 24, respectively, twisted, or twisted, with each other.

A cross-section perpendicular to the direction of passage of the cable 16 according to FIG. 4e is shown in FIG. 5. The network cable 16 has a circular cross section defined by the shield 68. Inside the shield 68 are the first, second, third and fourth wire 18, 20, 22, 24, the third and fourth wires 22, 24 having a larger one, in the illustrated embodiment, approximately twice as large the cross section of the wire than the first and second wire 18, 20.

The first and second wires 18, 20 are twisted together. As a result of twisting, an effective cross-sectional surface 70 is formed, which is necessary for the first and second wires 18, 20 twisted together. The effective cross-sectional surface 70 approximately corresponds to the cross-section of the third and fourth wires 22, 24.

LIST OF POSITIONS

10 - control system

12 - the first control computer

14 - second control computer

16 - network cable

18 - the first wire

20 - second wire

22 - third wire

24 - fourth wire

26 is a circuit element PHY

28 - capacitor

30 - first transceiver

32 - second transceiver

34 - resistor

36 - control computer

38 Ethernet switch

40 - computing unit

42 - emergency shutdown unit

44 - emergency switch

46 - input unit

48 - peripheral interface

50 - workflow

60 - plug

62 - case element

64 - crimp section

65 - cavity

66 - pin output

68 - screen

70 - effective cross-sectional surface

Claims (10)

1. The control system (10) for use in underground mining with at least two control computers (12, 14, 36) and at least one network cable (16) connecting the control computers (12, 14, 36) moreover, the control computers (12, 14, 36) are made for data transmission on the first wire (18) of the network cable (16) by means of high-frequency signals, characterized in that each control computer (12, 14, 36), in addition, made to transmit data at least on the first wire (18) network cable (16) via low-frequency signals. 2. The control system (10) according to claim 1, characterized in that the high-frequency signals are supplied to the network cable (16) with capacitive coupling. 3. The control system (10) according to claim 1 or 2, characterized in that each control computer (12, 14, 36) contains at least one transceiver (30, 32) and / or a receiver for transmitting low-frequency signals, connected with a network cable (16), in particular with resistive coupling. 4. The control system (10) according to claim 1, characterized in that the high-frequency signals are formed according to the One-Pair-EtherNet (OPEN) standard. 5. The control system (10) according to claim 1, characterized in that an Ethernet switch (18) is provided in each control computer (12, 14, 36). 6. The control system (10) according to claim 1, characterized in that the low-frequency signals are an emergency shutdown signal and / or control signals for or from machines, such as, for example, time or position signals. 7. The control computer for the control system (10) according to claim 1, characterized by a physical interface (26), with capacitive coupling supplying high-frequency signals to the first wire of the network cable, and at least one transceiver (30, 32) and / or receiver connected to the first wire (18) of the network cable (16), in particular with resistive coupling. 8. A network cable (16) for the control system (10) of at least one of the claims. 1-6, characterized by exactly four wires (18, 20, 22, 24), namely, in particular, twisted together, the first and second wires (18, 20), as well as the third and fourth wires (22, 24) having a larger wire cross section than the first and second wire (18, 20). 9. A network cable (16) according to claim 8, characterized in that the first and second wires (18, 20) are twisted together, and the effective cross-sectional surface (70) resulting from twisting corresponds approximately to the cross-section of the third and / or fourth wire (22, 24). 10. A plug connector (60) for a network cable (16) according to claim 8 or 9, characterized in that the plug connector (60) is connected to the network cable (16) by means of a single crimp and is configured to electrically connect the network cable (16) with a control computer (12, 14, 36).

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