GB2423680A

GB2423680A - Data transmission over an existing interface of an electrical power tool

Info

Publication number: GB2423680A
Application number: GB0602649A
Authority: GB
Inventors: Ulrich Single
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2005-02-11
Filing date: 2006-02-09
Publication date: 2006-08-30
Anticipated expiration: 2026-02-09
Also published as: DE102005006358B4; JP2006218621A; GB0602649D0; DE102005006358A1; GB2423680B

Abstract

An existing interface 3 of an electrical device 1, for example an electrical power tool 2 is also used for data transmission. One embodiment describes the transmission of data over the existing AC power line using various techniques including frequency changing. Another embodiment describes transmitting data over an existing signalling LED (for example, by flashing at a rate greater than the human eye is able to detect and being received by a light sensitive detector, preferably through an optocoupler (13)). The data to transmit can be stored on an on-board microcontroller and can include operating data, guarantee information or be used as passive theft protection.

Description

Data transmission facility for an electrical device, particularly an

electrical tool, and corresponding method The invention concerns a data transmission facility for an electrical device, particularly an electrical tool.

Electrical devices, such as in particular electrical tools, are known in different forms for various functions. Such electrical devices are increasingly equipped with electronic components, e.g. microcontrollers. Such equipment makes it possible to increase the number of functions. Such electrical devices often have signalling facilities which signal a specified state of the electrical device. As the signalling facility, for instance, light- emitting diodes which signal a specified state of the electrical tool are used.

In principle, it is desirable to increase the number of functions for such electrical devices.

On the basis of the method according to the invention, that is providing at least one transmission unit and/or at least one reception unit for data transmission, at least one existing interface of the electrical device being also used for data transmission, the range of functions of such an electrical device is considerably increased. Through the transmission unit and/or reception unit of the data transmission facility, data transmission is possible, i.e. the electrical device can output data and, for instance, feed it to an external remote station, and/or an external remote station forms a transmission unit which transmits data to the electrical device. In this case, the electrical device has a reception unit which co-operates with the transmission unit. Obviously, it is also possible to carry out bidirectional data traffic, so that the electrical tool has a transmission unit and a reception unit, and the remote station also has a transmission unit and a reception unit. By using an interface (of the electrical device) which already exists for other purposes, and is also used for data transmission, no additional expense is caused, i.e. the data transmission according to the invention can be implemented with very simple means.

According to the invention, an interface which, for instance, signals states of the electrical device, optionally the above-mentioned lightemitting diode (LED), can carry out a further interface function, that is transmit data simultaneously with signalling the operating state. For instance, it is possible to transmit data which reproduces the serial number of the electrical device, concerns the date of manufacture, gives production parameters or describes operating parameters and/or further operating parameters. Obviously, other interfaces are considered, and are used for data transmission according to the invention. For instance, an electrical tool may have a mains connection which is used for energy supply. This connection can also be used as a data transmission interface. If there is an electrical tool which is operated by battery, interfaces which previously carried out exclusively other functions can be used, for instance those which are used to connect and/or charge the battery or to output information, for instance display information or light-emitting diode information. For instance, in the case of the above-mentioned display it is possible that the display, when required, flashes invisibly for the human eye, i.e. uses such a high flashing frequency that the observer does not notice this flashing frequency, but it can be detected by means of an appropriate remote station and the data content can be captured.

According to an extension of the invention, it is provided that as the interface, a signalling facility of the electrical device is also used to transmit data. As indicated above, a mains connection of the electrical device can be used as the interface. In particular, the mains connection on the electrical device can be in the form of a device socket, and/or a mains cable plug is provided on a mains cable of the electrical device, and simultaneously forms the interface for data transmission.

The above-mentioned signalling facility can form a transmission unit, in which case, in particular, a reception unit co-operates with this transmission unit.

This co-operation can preferably take place without wires.

If the signalling facility is an optical signalling facility, the data transmission is carried out via the optical route. As indicated above, the optical signalling facility can be in the form of a light-emitting diode (LED).

It is also advantageous if the electrical device has the at least one transmission unit and/or reception unit for electrical data transmission. Thus, on the electrical device, the transmission unit or the reception unit or both units can be formed. If the electrical device has the transmission unit, a remote station which has a reception facility is provided. If the electrical device has only the reception unit, the remote station will have a transmission unit. If the electrical device has both a transmission unit and a reception unit, the remote station will also be equipped with a transmission unit and a reception unit.

Thus in total, either data can be transmitted from the remote station to the electrical device or data is transmitted from the electrical device to the remote station. The above-mentioned further variant provides the possibility of a bidirectional data exchange between the electrical device and the remote station.

An extension of the invention provides that a remote station which is not formed on the electrical device is provided, and has at least one transmission and/or reception unit for electrical data transmission.

Accordingly, in this case, the data transmission is carried out via the electrical route not the optical route, and can be carried by cable or not carried by cable.

The remote station can have, in particular, an optical reception unit as the reception unit. Such a reception unit can, for instance, co-operate with a light-emitting diode of the electrical device. It is conceivable that the remote station is connected to the mains connection of the electrical device, and has at least one transmission and/or reception unit as an electrical transmission and/or reception unit. Thus in such a case, the mains connection is not only used for electrical power supply to the electrical device, but also simultaneously as the data transmission path.

To receive optical data from the electrical device, the remote station has, in particular, an optical reception unit, preferably a lightsensitive element.

An extension of the invention provides that between the optical signalling facility and the optical reception unit, to improve the transmission properties, in particular as protection from interfering external influences, an opto- coupler is arranged, or can be arranged between these parts. This can be, for instance, an optical fibre element and/or also a screening element against external light.

It is advantageous if the transmission unit of the electrical device and/or the transmission unit of the remote station, to generate data, have a phase shift facility, a phase angle facility, a mains frequency changing facility, a pulse width modulation facility, a voltage curve changing facility, a current curve changing facility or an amplitude modulation facility. Accordingly, in the case of a phase shift facility, a change of the phase angle represents the generation of data which is transmitted. In the case of a phase angle facility, changes of the phase angle represent state changes which represent the data. This correspondingly applies to the mains frequency changing facility, i.e. frequency changes represent a data stream. A change of the pulse width by means of the pulse width modulation facility is used to represent data. In the case of a voltage curve changing facility, the voltage curve is influenced, and this change is interpreted as data. Finally, a data stream can be generated by amplitude modulation of the amplitude modulation facility. About the above-mentioned options, which can be used singly or in combination, for clarification, it should be noted again here that these measures are used to generate data, and not, or at least not only, to carry out the normal operation of the electrical device or electrical tool.

The invention also concerns a method of data transmission for an electrical device, particularly an electrical tool, in which at least one transmission unit and at least one reception unit are provided, and data transmission is carried out by shared use of at least one existing interface of the electrical device.

The drawings illustrate the invention on the basis of embodiments.

Fig. 1 shows a schematic representation of an electrical device in the form of an electrical tool, with interf ace, Fig. 2 shows a data transmission facility with an electrical device and a remote station, optical data transmission taking place between the elements, Fig. 3 shows the arrangement of Fig. 2 with an opto- coupler, Fig. 4 shows a data transmission facility with an electrical device and a remote station, electrical data transmission being carried out between the elements, Fig. 5 shows a further embodiment of an arrangement according to Fig. 4, Fig. 6 shows an arrangement corresponding to Fig. 3, Fig. 7 shows an arrangement corresponding to Fig. 5, Fig. 8 shows diagrams and an arrangement to change a frequency, to generate a data stream.

Fig. 1 shows schematically an electrical device 1, which is in the form of an electrical tool 2. For instance, this can be a right angle grinder which is equipped with electronics, for instance to set its rotational speed. The electrical device 1 has at least one interface 3, which forms the mains connection 4. This involves a mains cable with a mains cable plug, i.e. the electrical connection contacts of the mains plug form an interface via which electrical energy is transmitted, to drive the drive motor of the right angle grinder and also power the electronics.

According to the invention, this interface 3 is additionally used for another purpose, that is to carry out data transmission. This interface 3 is therefore used as the interface for data transmission, and also - as mentioned above - as the interface for energy transmission.

The interface accordingly has a dual function. Since in this way no separate interface has to be formed for data transmission, but an existing interface undertakes the data transmission function, a very simple implementation of data transmission is created. The interface 3 of the electrical device 1 of Fig. 1 can be used to transmit data out from the electrical device 1, i.e. the data is transmitted by the electrical device 1, so that consequently the electrical device 1 has a transmission unit 5 for the data.

The transmission unit 5 accordingly transmits a data stream to the interface 3. At the interface 3, a remote station (not shown) will receive the data stream and analyse it appropriately. Alternatively, it is also possible that the remote station (not shown) has a transmission unit, and that the electrical device 1 has a reception unit 6 for the data, so that information is fed to the electrical device 1 via the interface 3. A further alternative can be provided, that the electrical device 1 has both the transmission unit 5 and the reception unit 6, and that the abovementioned remote station is also equipped with a transmission unit and a reception unit. In such a case, a bidirectional data exchange takes place via the interface 3.

The embodiment of Fig. 2 shows an electrical device 1, which is also in the form of an electrical tool 2 and has an interface 3 in the form of a signalling facility 7. The signalling facility 7 is an optical signalling facility 8, which is in the form of a light-emitting diode 9 (LED) . For instance, this light-emitting diode signals to the user of the electrical tool 2 a particular operating state, for instance whether voltage is supplied to the electrical tool 2. This light-emitting diode 9 accordingly signals by its lighting the connected state, i.e. that its mains connection is connected to a power source. The light- emitting diode 9 is simultaneously used to generate a data stream, to output specified information via the electrical tool 2. By flashing and/or modulation of the light which is output by the light-emitting diode 9, the data which is fed - according to the arrow 10 - to an optical reception unit 11 of a remote station 12 is generated. In this case, therefore, the data stream is fed, without contact, from the electrical tool 2 to the remote station 12, and can be analysed at the remote station 12.

According to Fig. 3, the optical coupling between the electrical tool 2 and the remote station 12 can be improved by an opto-coupler 13 being between the light-emitting diode 9 and the optical reception unit 11, and being in the form of a screening unit, to screen out interfering light influences caused by daylight or other light sources. The opto-coupler 13 can involve, additionally or alternatively, an optical fibre, which carries out the optical data transmission specially effectively and without interference.

Fig. 4 shows an embodiment in which the electrical device 1 is in the form of an electrical tool 2, and has as the interface 3 a device socket 14, to supply electrical energy to the electrical tool 2 via a mains cable 15 and a mains cable plug 16, which is plugged into the device socket 14.

The interface 3 is also used to carry out a data transmission path via the mains plug 16 and mains cable 15 to a remote station 12. The remote station 12 is used on the one hand for data transmission, and on the other hand provides the energy supply for the electrical device 1.

In the case of the embodiment according to Fig. 5, the electrical device 1 in the form of an electrical tool 2 has a permanently installed mains cable 15, at the free end of which a mains cable plug 16 is arranged, and is connected via a counterpart socket 17 to a remote station 12. Via the electrical connection which is formed in this way, energy is supplied to the electrical device 1 from the remote station 12, and simultaneously a data path is created, so that for instance a bidirectional data exchange can be carried out. This means that the electrical tool 2 has a transmission unit 5 and a reception unit 6. The remote station 12 is accordingly equipped with a transmission unit 18 and a reception unit 19.

Fig. 6 clarifies the arrangement of Fig. 3, the optical transmission elements being shown in detail. The electrical tool 2 is provided - as mentioned above - with the light- emitting diode 9 as the signalling facility 7, which is used as the standardised display unit. According to the invention, it also takes on the function of data transmission, i.e., for instance, light which is modulated corresponding to the data transmission is fed via the opto- coupler 13 to a phototransistor 20 of the optical reception unit 11, which is at the remote station 12, which forms an analysis unit 21 for the data. To receive the data, the analysis unit, with the phototransistor 20 which represents a light-sensitive element, is kept on the outside of the housing of the electrical tool 2, so that it can read and analyse the data. Instead of the above-mentioned phototransistor, a photodiode or another light-sensitive electronic sensor can be used. The above-mentioned opto- coupler 13 provides protection from environmental influences, so that by using it a good optical coupling between the signalling facility 7 of the electrical tool 2 and the optical reception unit 11 is ensured. Interfering inward light couplings by daylight or similar light sources can be reduced by additionally provided screening (not shown) . The electrical tool 2, by means of its transmission unit 5, transmits data in the form of a serial data stream to the analysis unit 21, which has a reception unit 6 which is used as a receiver and analyses this serial data stream.

In the simplest case, it can be provided that a logical one is signalled by the display unit (light-emitting diode 9) as bright light, and a logical zero as "dark", i.e. switched-off light-emitting diode 9. The data is transmitted by a sequence over time of light and dark signals, similarly to Morse code. To be insensitive to interfering environmental influences during data transmission, various standards regarding data transmission protocols and/or modulation methods from telecommunications and optics are available. It is unnecessary to go into this situation as part of this explanation, since it is known to the person skilled in the art who is becoming active here.

Fig. 7 clarifies the version of Fig. 5. It can be seen that the electrical tool 2 is connected to an alternating voltage source 23 via the mains cable 15, the mains cable plug 16, the counterpart socket 17 and the cable 22, and the alternating voltage source 23 is connected to a transmission unit 18 via an electrical connection 24. The alternating voltage source 23, electrical connection 24 and transmission unit 18 belong to the remote station 12. Now, to be able to transmit data from the remote station 12 to the electrical tool 2 without a special interface on the electrical tool 2 being required, use of the energy supply connection, i.e. the cable 22, counterpart socket 17, mains cable plug 16 and mains cable 15, is shared.

In the simplest case, for data transmission it is possible to carry out a deliberate variation of the mains frequency of the alternating voltage source 23. Alternatively, burst control or another kind of influence on the mains waveform is also possible, to transmit data to the electrical tool in this way. As another alternative, deliberate variation of the mains amplitude can be used for data transmission (amplitude modulation).

If data transmission is carried out using deliberate variation of the mains frequency, the following example of it will be explained and presented in more detail on the basis of Figs. 7 and 8. For instance, the electrical tool 2 of Fig. 7 is a right angle grinder, which has electronics to make electronic control of the rotational speed possible. In the following example, all that is considered is that data is transmitted from the remote station 12 to the electrical tool 2. Obviously, it is also possible to carry out reverse data transmission or bidirectional data transmission. Preferably, in the case of the embodiment of Figs. 7 and 8, for data transmission a serial data stream is transmitted to the electrical tool 2. In the upper diagram of Fig. 8, a course of a digital signal with amplitude a over time is shown. t identifies the time. T represents the period duration. The arrow 25 indicates that a modulator 26 is controlled by the digital signal. This is a so-called 2FSK modulator. The digital signal has two states, a logical zero and a logical one. At time t equal to zero, the digital signal is zero until time t1. At time t1, the level of the digital signal then rises to logical one until the end of the period T. By means of the digital signal, an electronic switch 27, depending on the state, logical zero or logical one, is switched in such a way that either the alternating voltage source 23 with frequency f or the alternating voltage source 23' with frequency f2 is fed via the switch 27 to a connection 28.

With reference to Fig. 7, the explained arrangement of Fig. 8 is in the remote station 12, in order to influence the mains frequency in this way, i.e. a corresponding mains voltage, as is shown in the lower diagram of Fig. 8, is made available to the electrical tool 2 via the connection 22, 17, 16, 15. The amplitude pa of the mains voltage is shown depending on the time t. Whenever a logical zero is present on the basis of the digital signal, a lower frequency is fed in than when a logical one is present, since then the higher frequency is used. For instance, if the frequency f1 = 70 Hz and the frequency f2 = 140 Hz, and the time span for which the logical zero is present is msec and the time span of the logical 1 is 40 msec, the result is a mains voltage which varies in mains frequency according to the lower diagram of Fig. 8. In this way, a data stream is generated by a discrete variation of the mains frequency being carried out in the desired fashion.

Obviously, this method is not restricted to the variation of a sinusoidal alternating voltage. Other curve shapes such as rectangular, triangular or a variation or overlaying of these signals can also be used. The analysis is also not restricted to the analysis of the mains frequency. It is obviously also conceivable, additionally or alternatively, that the control takes place by means of phase angle control, and the phase angle is analysed by the receiver, i.e. by the electrical tool. Another or additional possibility is to carry out the control using burst control. The mains half-waves can then be analysed.

It is also conceivable, additionally or alternatively, that the amplitude of the mains voltage is modulated and analysed correspondingly. Combinations or variations of all the possibilities which are presented in this application are also conceivable.

For data transmission, various codings and/or modulation methods can be used. For instance, Manchester coding, Miller coding, differential coding or corresponding methods which are known from telecommunications can be used. These methods are not described in more detail since they are known to the person skilled in the art.

From the foregoing, it becomes clear that parallel to the energy transmission path a data transmission link is created, without the necessity of implementing an additional interface. Conventional rotational speed controllers such as are used, for instance, with the electrical device, in particular right angle grinders, work with the method of phase angle control. Analysis of the mains frequency is inherently required, to generate phase angle control synchronised with the mains. Accordingly, with the technology until now analysis of the mains frequency is inherently present in the rotational speed controller. According to the invention, this analysis can additionally be used so that an analysis of the data stream can be carried out. In this respect, in the case of electrical tools with digital rotational speed control, often only a change to the software is necessary so that data analysis according to the invention can be carried out. Depending on the application case, that results in no or only a very small increase of the unit costs.

According to the invention, data transmission from the electrical device 1, particularly electrical tool 2, to the analysis unit, i.e. to the remote station 12, without the electrical device 1 having as standard a display facility, signalling facility or similar, as was explained in the case of the embodiment of Fig. 6, is nevertheless possible.

For this purpose, as in the case of the previously mentioned data transmission to the electrical tool, the energy transmission path is used as the data transmission link. For instance, a deliberate variation of the phase angle is used. For instance, the serial data stream is then generated by the electrical device 1 outputting a phase angle of, for instance, 500 for a logical zero and a phase angle of, for instance, 130 for a logical one. The phase angles are captured by an external analysis unit and converted into corresponding data. So even if no signalling facility 7 is present as standard, on the basis of this method data transmission can be additionally carried out via the mains connection. The fact that on the basis of the method described above for instance an electric motor of the electrical tool 2 does not rotate under permanent control in particular states, but because of the data transmission even takes uncontrolled states for short periods, is not a disadvantage.

In many application cases, it can be not useful or even interfering if the interface to data transmission is active in all operating cases. For instance, if data transmission from the electrical tool 2 to the remote station 12, i.e. to the analysis unit, is to be implemented, and an operating data memory with the user data can be read out using it, this function could interfere with, for instance, the signalling facility 7, which represents a display unit, in normal operating mode. This can be prevented by different operating modes of the electrical tool 2. In the simplest case, the interface becomes active regarding data transmission only if, for instance, the user deliberately initiates activation using an additional switch.

Alternatively, if no additional switch for activation is provided, for instance abnormal operating states can be used to activate the interface with respect to data transmission. The following is an example: In the case of an electrical tool 2 with restart lockout, the mode to read out the operating data memory, i.e. for data transmission, is activated by the following preconditions: The electrical tool 2 is connected to the supply voltage in the switched- on state. The speed control potentiometer in the handle of the electrical tool is reduced from the "maximum speed" position to "medium speed". The speed is then increased by the speed control potentiometer from "medium speed" to "maximum speed". The electrical tool 2 then sends the operating data from the operating data memory in the form or a serial data stream via the display unit which is present as standard, e.g. via a light-emitting diode.

Because these operating state changes as explained above are not common, it is highly probable that the data transmission is not unintentionally activated by the user.

The data transmission which takes place by means of the invention can be used, for instance, to read out an operating data memory of the electrical device, using which the behaviour of the machine can be analysed, for instance to give special discounts for maintenance and servicing, or to give targeted advice in the choice of a new machine on the basis of the existing operating data. It is also possible to give a guarantee without a sales slip, since the data of the operating data memory makes this possible.

Additionally, passive theft protection can be implemented, or a diagnostic interface can be made available for servicing. Since the electrical devices which are usual today, particularly electrical tools, are provided with digital electronics, e.g. a microcontroller etc., these electronics can additionally be used for data transmission according to the invention.

Using the invention, any data can be transmitted to and from an electrical device, and can also optionally be stored in it. As a further example of the application of the invention, the following should be mentioned: By means of the data transmission according to the invention, activation of one or more special modes of operation of the electrical tool can be simplified, for testing or production of the electrical tool. For instance, in the case of an electrical right angle grinder, the "restart lockout" should be deactivated during production. During the production process of this electrical tool or another electrical device, it is normally switched on and off several times. If the electrical device/electrical tool is equipped with a restart lockout, the electrical device only runs properly if it is first connected to mains voltage and then switched on using the device switch. Switching on the electrical device/electrical tool via the mains switch, after it is connected to mains voltage, is possible in production only at considerable cost. Usually, the mains switch of the electrical tool is locked in the switched-on state, and it is switched on and off by switching the supply voltage on and off at the supply voltage input (mains cable) of the electrical tool. If the restart lockout is active, the electrical tool then does not function. By using the method according to the invention, the restart lockout can be deliberately deactivated during the production process of the machine, so that the production process is simplified and improved regarding the cost structure.

On the basis of the data transmission according to the invention, data canbe stored. Storing and reading out data, e.g. user data such as serial number, purchase date, user name, passive theft protection etc., is also possible.

On the basis of the method according to the invention, contactiess reading out of a memory, particularly an operating data memory of the electrical device, can be carried out. It is also possible to activate supplementary functions. For all electrical tools from a particular batch onward, the same electronics are used. In the production process, particular functions are then activated or deactivated. The software versions to be managed are thus considerably reduced. On the basis of the data transmission according to the invention, storage of production parameters is also possible. Fine adjustment of the electronics can also take place by means of the method according to the invention, so that the electronics and, for instance, the motor of the electrical device can be better adapted to each other. Finally, it is also possible to store service parameters.

Claims

Claims 1. Data transmission facility for an electrical device (1),

particularly an electrical tool (2) characterized by at least one transmission unit (5) and/or at least one reception unit (6) for data transmission, use of at least one existing interface (3) of the electrical tool (1) being shared for data transmission.
2. Data transmission facility in Claim 1, characterized in that as the interface (3) a signalling facility (7) of the electrical device (1) is also used to transmit data.
3. Data transmission facility according to one of the preceding claims, characterized in that as the interface (3), a mains connection (4) of the electrical device (1) is used.
4. Data transmission facility according to one of the preceding claims, characterized in that the mains connection (4) on the electrical device (1) is in the form of a device socket (14) and/or a mains cable plug (16) on a mains cable (15)
5. Data transmission facility according to one of the preceding claims, characterized in that the signalling facility (7) is a transmission unit (5)
6. Data transmission facility according to one of the preceding claims, characterized in that a reception unit (19) co-operates with the transmission unit (5) particularly without wires.
7. Data transmission facility according to one of the preceding claims, characterized in that the signalling facility (7) is an optical signalling facility (8) for optical data transmission.
8. Data transmission facility according to one of the preceding claims, characterized in that the optical signalling facility (8) is a lightemitting diode (9)
9. Data transmission facility according to one of the preceding claims, characterized in that the electrical device (1) has the at least one transmission unit (5) and/or reception unit (6) for electrical data transmission.
10. Data transmission facility according to one of the preceding claims, characterized by a remote station (12) which is not formed on the electrical device (1), and has at least one transmission unit (18) and/or reception unit (19) for electrical data transmission.
11. Data transmission facility according to one of the preceding claims, characterized in that the remote station (12) has an optical reception unit (11) as the reception unit (19)
12. Data transmission facility according to one of the preceding claims, characterized in that the remote station (12) is connected to the mains connection (4) and has the at least one transmission unit (18) and/or reception unit (19) as the electrical transmission unit and/or reception unit.
13. Data transmission facility according to one of the preceding claims, characterized in that the optical reception unit (11) of the remote station (12) has a light-sensitive element.
14. Data transmission facility according to one of the preceding claims, characterized in that between the optical signalling facility (8) and the optical reception unit (11) an opto-coupler (13) is or can be arranged.
15. Data transmission facility according to one of the preceding claims, characterized in that the transmission unit (5) of the electrical device (1) and/or the transmission unit (18) of the remote station (12), to generate data, have a phase shift facility, a phase angle facility, a mains frequency changing facility, a pulse width modulation facility, a voltage curve changing facility, a current curve changing facility and/or an amplitude modulation facility.
16. Method of data transmission for an electrical device (1), particularly an electrical tool (2) , with at least one transmission unit (5) and at least one reception unit (6), characterized by the shared use of at least one existing interface (3) of the electrical tool (1) for data transmission.
17. A data transmission facility substantially as herein described with reference to the accompanying drawings.
18. A method of data transmission substantially as herein described.