JP6467016B2 - Wireless tag and time slot communication system - Google Patents

Description

  The present invention relates to a communication system with a wireless tag.

  For example, DE 4439074A1 is known as the system listed at the beginning. According to this document, at the time of preamble transmission, all wireless tags must be in an active state in order to allow simultaneous data transmission to the wireless tag in a classified period. This procedure is less energy efficient or system efficient. Further, in WO2010 / 004349A1, a system in which wireless tags of individual time slots are classified is known. This sends a preamble to synchronize with the communication station. This preamble includes more data packets that indicate an error relative to the reference time for the synchronization state between the communication station and the wireless tag. The wireless tag goes from sleep state to active state to a time defined by the internal time base and within the appearance of the preamble, where it receives one of the data packets. In order to newly adjust the next wake-up time and thus maintain synchronization with the communication station, the wireless tag uses the data packet received each time and the reference time error encoded in it. The internal time base is corrected. However, the next preamble for use has been found to be disadvantageous because it causes a relatively high amount of data.

DE4439074A1 WO2010 / 004349A1

  The present invention addresses the task of providing a system that avoids the problems discussed at the outset.

The object of the present invention is solved by the wireless tag according to claim 1 and the system according to claim 16 .

  Accordingly, an object of the present invention is a system in which a plurality of time slots are provided for communication per time slot cycle in a repetitive sequence, and each time slot is given a unique time slot symbol. A system including a communication station for communicating with a plurality of wireless tags using a slot communication method, wherein the communication station emits a synchronized data signal including its time slot symbol for the current time slot The wireless tag is switched from the sleep state to the active state at the wake-up time, receives the synchronization data signal in the active state, and the received time slot symbol is the time slot specified in the wireless tag. To display the subsequent time slot cycle Im slot cycle, is configured to define a new wake-up time corresponding to the next occurrence of the time slot that is specified, a system.

  The measures according to the present invention simultaneously have the advantage that the synchronization state between the communication station and the wireless tag is as simple as possible and nevertheless recognized and maintained in the most robust manner and guaranteed during system operation. . Unlike known measures, here it is no longer necessary for all radio tags to be active simultaneously with a specified time in order to remain synchronized with the time scan of the time slot communication method defined by the communication station. Absent. Similarly, with regard to the processing of this data and the total amount of data when communicating with the communication station, it can be seen that the reception and evaluation of data notifying the time error from the reference time, which is very expensive, can be omitted. It was. According to the present invention, each wireless tag participating in the communication with the communication station only needs to make a notification via the time slot symbol indicating the time slot designated for the notification. Therefore, each of the wireless tags individually corresponds to the occurrence of a time slot symbol important for notification, confirms the time slot symbol important for notification, and uses it to determine the next wake-up time. It is defined by the timing of the time slot communication method set by the communication station. Thereby, it is perfectly sufficient for the time slot symbol to uniquely identify each time slot, for example using an individual time slot identification signal for each time slot. In order to synchronize the communication station and the radio tag, no further information encoded in the synchronization data signal and described with respect to the known procedure is necessary. The wireless tag appears alone at the time expected by the wireless tag or during the expected period, depending on the identification status of the time slot symbol indicating the time slot designated for the wireless tag, Check the synchronization status of.

  Time slot communication method in which the next wake-up time is automatically known to the wireless tag when the wireless tag switches to the sleep state again after the wireless tag confirms its synchronization state as described above This is basically sufficient because it is known for time scanning. Therefore, the definition of a new wake-up time is that a radio tag, for example a time manipulation stage (e.g. a timer), is started anew with a timing parameter that has already been used to switch from sleep to active previously. Limited. The wireless tag then switches back to the sleep state, where it is triggered by a time operation, again until the wakeup and switch from the sleep state to the active state are performed at the new wakeup time in the next time slot cycle. . However, the radio tag does not have to stay forced for the rest of the time slot designated for it in the sleep state, and can also handle additional tasks in the active state during the time slot or during the time slot cycle. . Also, the time manipulations described so far operate in the background independently of other activities. The definition of a new wake-up time is realized by specifying an absolute or relative time task, e.g. relative to the time of appearance of the synchronized data signal or after an active state until further to that time Relative to the time at which the state is taken or relative to the time at which the end of the synchronized data signal occurs until that time. However, the definition of a new wake-up time is that the time slot symbol is received, the subsequent sleep state after the active state, or the sum of the sleep and active periods, or various such states. The total duration of the column can also be interpreted to specify a new wake-up time. Each radio tag operates its own time manipulation stage, and the exemplary variability in movement of each electronic component is not excluded, so a new wake-up time definition exists for each radio tag, the time that exists individually. It can also include bass drift. For this purpose, for example, in a radio tag, the time difference between the expected and actual occurrence of a synchronized data signal having a time slot symbol indicating the time slot designated for each radio tag is measured, The appearance timing is evaluated by the time manipulation stage for correction. However, compensation is only used when the synchronized state is confirmed. However, if another time slot symbol is received at the expected time slot symbol location, there is no synchronization state and the radio tag must then perform a new synchronization that is further picked up.

  In the time slot communication method, m time slots, for example, 255 time slots are used within n seconds, for example, 15 seconds. Therefore, in this time slot communication method, m time slots within one time slot cycle for one communication are used using a wireless tag. Each of the wireless tags can be classified into one of the time slots, where more wireless tags can also be classified into designated time slots.

  Basically, one wireless tag has one wireless communication stage, also called a transceiver, and a logic stage that cooperates therewith. The logic stage can be realized, for example, entirely in hardware, or can be realized by a single microcontroller with one microprocessor and storage element or integrated storage element, which storage element Now, the stored software is operational. One tag can receive a wireless signal using its wireless communication stage, can process received data contained in this wireless signal using a logic stage, and in some cases can generate reply data using a logic stage, It is again emitted as a radio signal via the radio communication stage. The wireless communication stage has means for wireless communication and means for converting an analog signal into a digital signal or vice versa.

  Such a wireless tag can have an energy storage element, such as a battery or a solar panel coupled with a rechargeable battery, for its energy supply. In order to operate with maximum energy efficiency, wireless tags have several operating conditions. One wireless tag has a relatively high energy consumption when in an active state. The active state exists when data is transmitted / received, display is updated, or battery voltage is measured. On the other hand, energy consumption is relatively low in the sleep state. Preferably, as many electronic components as possible are operated with the current supply cut or darkened, or at least in the mode of as little energy requirement as possible. The active state mainly has a time slot for communication with the communication station designated for the wireless tag. In the active state, the radio tag has, for example, preparations for reception in order to receive commands and possibly received data from the communication station and to process it using logic stages. In the active state, the logic stage can also be used to generate transmission data and communicate with the communication station. Outside the time slot designated for the wireless tag, the wireless tag is primarily operated in a sleep state that saves energy. In the sleep state, the logic stage or time manipulation stage only performs the activities necessary for the timing for the right time wakeup so that the wireless tag receives the synchronized data signal and / or Alternatively, the next time slot designated for the wireless tag is ready for communication with the communication station. To operate with high energy efficiency and thereby achieve the longest possible lifetime of the RFID tag, keep the synchronized RFID tag in sleep as long as possible and data with the communication station in the shortest active period as possible There is a basic driving strategy of driving only when absolutely necessary for transmission.

  The communication station can be an autonomous device having a server function. Preferably, the communication station couples a disconnection site between, for example, communication that is cable-connected to an information processing device (for example, a server) and communication based on wireless without a cable using a wireless tag.

  In order to freely use communication with the communication station, first, the wireless tag is registered or classified by the communication station.

  Further particularly preferred forms and further configurations of the invention emerge from the dependent claims and the following description.

  Using the measures according to the present invention, not only can the synchronization state between the communication station and the wireless tag be ensured by a simple method, but also the wireless tag that is in the asynchronous state can be re-established in the time slot communication method. You can go back to the time diagram and therefore synchronize again. For this purpose, such an asynchronous RFID tag does not switch periodically as is the case when it is in a synchronized state, for example from its sleep state to its active state once at any time. Switch and stay active in preparation for reception. For example, if nothing is received in a specified period such as a time slot period, the sleep state is again entered, and reception attempts are repeated until another time. As soon as the synchronized data signal is received, the time slot symbol is utilized. Thereby, the received timeslot symbol most likely displays unspecified timeslots, which are autonomously confirmed by the radio tag. The radio tag knows the system of appearance of the time slot symbol, and in accordance with the evaluation of the received time slot symbol, in the existing time slot cycle (1st) or in the next time slot cycle For the first time (second time), it is determined voluntarily whether the designated time slot can be expected. In the first case, the wireless tag is configured to define one up to the next occurrence of a corresponding new wake-up time slot that is specified for it in the currently existing time slot cycle. The radio tag confirms by the evaluation of the received time slot symbol and by knowledge of the system of occurrence of the time slot symbol that the specified time slot will still appear in the currently existing time slot cycle. . In the second case, the radio tag will define one up to the next occurrence of the corresponding new wake-up time slot in the time slot cycle that follows the currently existing time slot cycle. Composed. The radio tag is currently present in the past in this time slot cycle because of the evaluation of the received time slot symbol and by knowledge of the system of occurrence of the time slot symbol. Make sure that it will no longer appear in the timeslot cycle. As described at the beginning of the description of the synchronization state, the above-described time operation is also used for this new wake-up time definition technique, where the time operation is driven by a timing parameter, and that parameter is used to enter the synchronization state. The desired start of is achieved. The timing parameter to be selected is derived from the specific knowledge for the use of the next time slot communication method for the radio tag, and therefore the parameter is specified by the logic stage.

  The definition of the correct wake-up time for each wireless tag is performed by the wireless tag based on knowledge of the parameters of the time slot communication method. This parameter can be looked up by or transmitted to the wireless tag upon its registration of the communication station, or it can already be programmed into the wireless tag in advance. In either case, the wireless tag has a storage stage for storage of parameters of the time slot communication method, and the wireless tag has access to and evaluates this parameter for the definition of a new wake-up time. If configured, it serves its purpose. This parameter can present all the details of the timing of the time slot communication method, for example, parameters relating to the passage of time for communication between the communication station and the radio tag, a predefined time or time interval Parameters related to the basic structure of the time slot communication method, for example, the total number of time slots, the time slot duration, the time slot cycle duration, or the details for confirmation of a single time slot A parameter related to a time slot symbol or an algorithm for calculating the time slot symbol. With this parameter, an asynchronous radio tag can determine whether a specified time slot can still be expected within a currently existing time slot cycle based on the time slot symbol just received, or a specified time slot. It can be easily and autonomously revealed whether the slot is already in the past and therefore the next designated time slot will appear in the next time slot cycle. The associated wireless tag calculates a new wake-up time in the active state, switches to the sleep state, switches to the active state at the calculated wake-up time, receives the time slot symbol of the specified time slot, and then enters the synchronized state again. Become. In order to receive the synchronized data signal in the designated time slot, the radio tag will first be active again in the next time slot cycle, unless further activity is expected from it in the existing time slot. Switch to.

  According to a further aspect of the invention, the wireless tag has a storage stage for storage of presentation of time slot symbols indicating designated time slots.

  Both storage stages (storage stage for parameter storage and storage stage for presentation) can be realized by a single storage chip or by different storage chips. Both storage stages can be integrated into this storage chip on different storage areas and can be subject to different access rights. However, both storage stages can also be realized with different storage elements based on safety technical considerations.

  It is clear that it is advantageous to configure the presentation of the time slot symbols using the wireless tag hardware address that uniquely identifies the wireless tag and to program it unchanged in the second storage stage. As a result, an undesirable false operation of the wireless tag is reliably avoided. Since each wireless tag has a unique hardware address, it is possible to create a strict and non-interfering classification according to the diagram for one time slot.

  Particularly preferably, the presentation of the time slot symbol described above is realized by the least significant bit or least significant byte of the hardware address, where with this group of bits used, at least present in the time slot cycle. The total number of time slots needs to be copyable. Thus, for example, for 256 time slots, only the least significant 8 bits or least significant byte of the hardware address is required, and for 128 time slots, only the least significant 7 bits are required. It is. In this context, it is advantageous if the total number of time slots corresponds to a power of two.

  The presentation of the time slot symbol or the time slot symbol itself can also consist of the hardware address described above and other programmed numbers.

  The radio tag is configured to check whether the known time slot symbols present at the time of receiving the synchronized data signal match each other. The confirmation can be performed, for example, using an algorithm that supplies a confirmation result to the processor of the wireless tag when the software describing the algorithm is activated. The algorithm can, for example, convert from a received time slot symbol to a presentation known to the wireless tag and then make a comparison. However, the radio tag can also translate back from the presentation known to the radio tag to the expected time slot symbol, and then convert the received time slot symbol to the expected time slot symbol. It can also be compared with a slot symbol. However, it is advantageous to make a simple comparison between two or binary coded symbols because this is a very fast and relatively low energy requirement to the processor level with a simple registration comparison. .

  Basically, for each time slot, an unambiguous confirmation for use defined in the system in advance can be made. However, in particular, the communication station is configured to generate time slot symbols as consecutive numbers (also referred to as “slot IDs”) of each time slot in response to the appearance of time slots in the time slot cycle. preferable. Thus, in each time slot cycle, number 1 is classified as the first time slot, number 2 is classified as the second time slot, and so on. By providing minimal data traffic in data transmission from the communication station to the wireless tag, it is possible to avoid time-consuming algorithms and generate time slot symbols in the simplest possible manner. Only one data packet used for synchronization needs to be transmitted. Thus, the amount of data in the transmission of certain time slot symbols for use per time slot or per time slot cycle is also hardly affected. Thus, channel registration is optimized because the total number of data packets per time slot or time slot cycle required for synchronization is as small as possible. The total number of time slots that occur in a time slot cycle is necessary to generate each number of time slots and ultimately determines the total number of bits that make up the data packets required for synchronization. Since each bit represents two states, it is advantageous if the total number of time slots per time slot cycle is a power of two. Therefore, the time period for receiving the time slot symbol can be shortened accordingly, which is advantageous for the energy balance of the wireless tag. In particular, if the part of the hardware address as the presentation of the time slot symbol known to the radio tag is used on the radio tag side, the received time slot symbol matches the stored time slot symbol. Confirmation can be done quickly and easily. The radio tag synchronizes with the communication station or the time scan of the time slot communication method defined thereby in a manner that is as simple as possible based on the number of time slots.

  Basically, the synchronized data signal can be configured exclusively via time slot symbols, e.g. address data for tag address processing or commands for sending commands from the synchronized data signal. Additional communication parameters required for communication between the communication station and the wireless tag, such as data, can be excluded. As explained so far, the time slot symbol is a very compact indicator for communication synchronization in the system, so in addition to the time slot symbol, it is conceivable to embed further information in the synchronized data signal, This will be discussed later.

  Therefore, according to a further aspect of the present invention, a communication station is configured to embed address data in a synchronized data signal, which is used to provide a plurality per time slot specified for the aforementioned radio tag. If the wireless tag is individually addressed, and the received time slot symbol indicates its designated time slot, the wireless tag evaluates the synchronized data signal with respect to the included address data, and It is configured to check whether the wireless tag is individually addressed.

  Similar to the use of the wireless tag hardware address associated with the time slot symbol, the communication station specifically identifies the wireless tag hardware address, omitting the least significant bit or least significant byte, and uniquely identifying the wireless tag. It may also be advantageous to generate address data using one or more of these bits or bytes. Therefore, in existing systems, the hardware address of the wireless tag is used for the unique address processing of each wireless tag. On the other hand, which time slot for the wireless tag is specified is defined by the least significant bit or the least significant byte. Therefore, in order to keep this time slot synchronously and to be individually addressable in this time slot, a relatively large number of radio tags can be placed in a single time slot. Accurately classified. Here, additional bits or bytes of the individual hardware address of the RFID tag are used to perform individual address processing of the special RFID tag. Moreover, the relevant radio tag that is just active in order to receive the time slot symbol does not need to switch to sleep during that time, in the existing time slot to check if address data is present, This treatment represents a significant contribution to system efficiency as it must be switched back to the active state at a later time. More precisely, it will be clear whether the radio tag is addressed for all radio tags that attempt to hear the synchronized data signal simultaneously in this relatively short phase of the active state.

  Similar to the address data embedding, if the communication station is configured to embed command data in the synchronized data signal, there is a further significant contribution to system efficiency, which is used to Commands can be sent on the radio tag of the time slot specified for the tag, and the radio tag is synchronized with respect to the included command data when the received time slot symbol indicates the specified time slot. Configured to evaluate the structured data signal and to execute the command. Thus, for example, a command can be sent to all wireless tags embedded in a specified time slot that are executed by a relatively large group of wireless tags without individually addressing.

  Basically, wireless tags can already perform standardized (pre-defined) tasks by identifying individual address processes without the need to receive explicit commands. However, address data for addressing each wireless tag and command data for command transmission are transmitted by this individual wireless tag so that the wireless tag evaluates the command data and executes the command. It can be seen that it is particularly preferred if the wireless tag is configured and addressed individually using address data. Therefore, sometimes a command for each wireless tag is transmitted in a relatively large group of wireless tags.

  According to a further aspect of the system, the wireless tag executes the command as a single time slot command and terminates the command executed within the single time slot in which the command was received. Advantageously, it is constructed. This allows for a quick and compact handling of requests that are offered to the wireless tag via the communication station. Such a single time slot command can be, for example, a so-called “PING” command, which can be used to determine whether a specified time slot exists or for example from one saved page or site to the other. It is only checked whether there is an internal processing command that causes as little external data traffic as possible, such as a switch command for switching to a saved page or site. The storage page is a logical area (one address area) in which data for one image or the like is arranged or stored in the storage element. Using a single time slot command, data for processing by the wireless tag (for example, data to be displayed using a display) is not transmitted to the wireless tag, but in some cases, internal processing of the data is performed. Only commands or commands that instruct the wireless tag to transmit information to the communication station are transmitted.

  In this connection, at the end of the executed command, the radio tag may be configured to generate confirmation data and to transmit confirmation data in each time slot in which the command is received. It is advantageous. Thus, further, data traffic generated by the confirmation remains limited to each time slot in which the command is transmitted. The next time slot remains unloaded according to the data, which favors system capacity.

  Further, the wireless tag can be configured to transmit confirmation data for a first portion of a time slot (eg, the first of the half or the first of the third), This first part does not touch the second part of the subsequent time slot before the appearance of the synchronized data signal of the next time slot located next in time in the synchronized data signal. This division of the structural or temporal time slot makes sure that the confirmation data often only requires a short transmission, and therefore the remaining part of the relevant time slot, ie the second, for further data traffic. Consider the situation where a part (eg the second of the half or the second and third of the third) is used undisturbed.

  It is here that the duration of each part of the time slot may not be defined by a numerical value set invariably and can be derived from the respective configuration or use of the time slot in a dynamic manner. Generally stated.

  In the system, for example, there are 58.6 milliseconds in 256 time slots in a 15 second time slot cycle, and 2 to 5 problem radio tags can be individually addressed per time slot. Individual tasks with a single timeslot command can be delegated to it. If each wireless tag is expected to communicate a request to several wireless tags per time slot and, therefore, it is expected to communicate all the wireless tags with the confirmation data in the existing time slots. It is advantageous to follow one arrangement principle. For this purpose, the wireless tag was also confirmed to address some wireless tags using address data in addition to its own address, and to evaluate those of other addressed wireless tags. It is configured to transmit confirmation data inside a period designated for transmission of confirmation data at a time determined by the address and corresponding to the order of the group of the addressed wireless tags. Since the communication station as the task requester knows the radio tag to be addressed, the transmission of the confirmation data requires only minimal data traffic, which is the communication station that contains the sequencing principle. Because it knows exactly in what order and therefore further up to which time or during which time period it will transmit the confirmation data contained.

  The wireless tag also has a multi-time slot command over several time slots to transmit a larger amount of data between the communication station and the wireless tag, so that the amount of data transmission is not enough for the time slot period. Is configured to execute commands. Processing of such commands can occur in adjacent time slots side by side or indirectly in adjacent time slots. Thus, for example, the command component can be the total number of used time slots, confirmation of used time slots, or a time slot group. The time slots used can be limited in time slot cycles, but can also be located jumping to several time slot cycles. Such a multi-time slot command relates to, for example, downloading a larger amount of data from the communication station or uploading such a data amount to the communication station from the viewpoint of the wireless tag. As with single time slot commands, multi-time slot commands also do not transmit data for processing by the wireless tag (for example, data for display using a display) to the wireless tag. Only a command for instructing internal processing of data and / or a command for instructing the wireless tag to receive data or transmit data at a later time is transmitted. After receiving the multi-timeslot command, the wireless tag can be switched to the sleep state to save energy again in order to autonomously manipulate the time and switch to the active state at the time when data transmission takes place. Here, in the frame of data transmission, new command communication, in particular, new address processing of the wireless tag is not required. This is because the communication station has already prepared the data up to the wireless tag by transmitting the multi-time slot command. This is because the transmission system is defined. Therefore, for example, in a wireless tag having a display, the address processing time of the wireless tag for receiving the data to be notified is completely separated from the actual transmission time of the data to be notified. The transmission of data to be notified can begin at that time in the current or other time slot. The transmission of data to be notified can be extended over different time slots of a time slot cycle and can be extended over several time slot cycles.

  If the multi-time slot command corresponds to data transmission from the communication station to the radio tag, it is advantageous if the communication station is configured to transmit the entire data distributed in several time slots, Here, one or several data packets as a part of the whole data are transmitted per time slot, and from each time slot, a second time slot part adjacent to the first part of the time slot transmits data. Used for In some cases, similar to the description for the single time slot command, the second part of the time slot (eg, 2 minutes) is used to avoid touching the other or first part of the time slot for other activities. Only the second of the 1's) is used. The same is valid for data transmission from the wireless tag to the communication station, with the necessary changes.

  In order to notify the communication partner that the partial task processing is performed in each time slot in the time slot series required for processing of the multi time slot command, the wireless tag executes each time slot in which the multi time slot command is executed. It is advantageous if it is configured to generate and transmit partial confirmation data.

  In a particularly preferred configuration of the system, the radio tag is configured to transmit partial confirmation data in the aforementioned second part following the received data packet and before the end of each time slot. . Thus, the entire data traffic generated by the multi-timeslot command is integrated into the second portion of the timeslot.

  Corresponding to the configuration of the wireless tag included in the system, the communication station is further configured to receive and process the confirmation data during the specified reception period. Therefore, confirmation data for a single time slot command is received in a period corresponding to the first portion of each time slot, and for a multi time slot command in a period corresponding to the second portion of each time slot. Confirmation data is received.

  In a preferred form of the system, the command processing methods described above are combined, so that the communication station can use the time slot designated for processing the multi-time slot command performed by the first radio tag. The second wireless tag is configured to be addressed using address data, and a single time slot command is transmitted to the second wireless tag using command data. In addition to transmitting a larger amount of data between the communication station and the first wireless tag, it is possible to assign an activity or task to the second wireless tag that generates a smaller amount of data for communication with the communication device. To. In this case, data communication with each wireless tag is processed in various parts of each time slot.

  According to a further aspect of the system, the communication station uses a command to send a wireless tag to a time slot specified for the wireless tag and for further wake-up times that do not correspond to the normal specified time slot of the wireless tag. The wireless tag can be used for data transmission with a communication station in a time slot different from the normal time slot of the wireless tag in the time slot communication method. ing. In addition to this, the wireless tag is configured to process this command and switch to the active state at the wake-up time forced by the communication station. This measure is important when communication with a designated wireless tag is being pushed to the communication station with the (highest) priority. The corresponding wireless tag then synchronizes itself using a time slot symbol indicating a time slot that is not normally specified for the wireless tag. After processing a task received in an unusual time slot, the corresponding wireless tag adapts to the normal time slot of the wireless tag again, synchronizes itself again, and prepares for communication with the communication station in a synchronized state. Is done.

  In order to be able to search for a communication station independently, the RFID tag can receive a synchronized data signal corresponding to a period of a time cycle, in particular in a period partially extended during that period. Confirmation is performed a plurality of times, and if a synchronization data signal does not come, the reception confirmation is performed again after switching the radio channel. Since each communication station occupies a different radio channel, the result of the absence of a synchronized data signal for the tag being searched is that there is no communication station for that radio channel or such communication. The station is out of range of the wireless tag, so other communication stations must look for it. This method may continue until a method of communication with the communication station is found and the wireless tag is registered at that station and can be used in the system.

  The search can be simplified by limiting the search of the synchronized data signal to a preset group of radio channels by the radio tag, and the radio channel is particularly useful when the radio tag is connected to a communication station. The station has transmitted in advance. This procedure is reasonable for newly integrated RFID tags, and for already integrated RFID tags that have been moved and disconnected from the communication station as a result of the move. Especially reasonable. The limitation of known radio channels is an energy saving method, and mainly to prevent collisions of radio channels taken by other machines such as conventional WLAN (Wireless Local Area Network, draughtless locals Network). Useful.

  A communication station can use all available radio channels at the start of the operation, in particular the radio channels previously incorporated into the program for the operation of the communication station, each radio channel being used by another communication station or its radio. Check if the channel is not used, and if there is such an unused radio channel configured to use this radio channel to communicate with the radio tag assigned to or must be assigned to the communication station This is an advantage in installing a new communication station in an existing system as easily and automatically as possible. The wireless channel already shown is known by the appearance of the synchronized data signal of another communication device on that wireless channel.

  The system of the present invention can include, for example, a plurality of communication stations at various spatial locations, each communication station designated by a selection of wireless channels to which a group of wireless tags is assigned to the communication station. it can. Thus, it is possible to manage groups of RFID tags in the system in a simple and robust manner, and for each group of RFID tags, the same time slot communication method is used on channels that are different from group to group.

  In a preferred form of the system, the wireless tag has a display unit for displaying an image, the image is structured from an image plane, each image plane is represented by image plane data, and the wireless tag is an image plane. Configured for individual reception of data and combining images by overlaying image planes, and the communication station is configured for transmission of each image plane data across time slots using radio tags . The advantage with this procedure is that only the image plane where the change occurs needs to be selectively transmitted from the communication station to the radio tag. Since the amount of data that must be transmitted is relatively small compared to the amount of data that must be transmitted in the case of full image content, the above procedure contributes significantly to system efficiency and energy efficiency. Furthermore, the compression of the image data for each image plane that must be transmitted can be optimized, thus minimizing the amount of data that must be transmitted. This is possible because there is usually a large “white” or “transparent” portion in the image plane that must be transmitted, where a very high compression ratio is achieved. Thus, since the amount of data that must be transmitted to perform the image update is reduced to a minimum, this treatment is kept low through activities where the energy requirement or energy consumption of the wireless tag is as low as possible, This has a very advantageous effect on the lifetime of the wireless tag.

  In this situation, the wireless tag is configured to change an existing image by receiving at least one new image plane of the image and replacing the existing image plane of the image with the image plane that was just received. sell. In this case, the above-described command can be used. In this way, for example, the image data of the corresponding image plane is stored in a new memory page in the wireless tag, and the download of the image plane image data is processed from the communication station to the wireless tag using multi-time slot commands. Can be done. After the download is complete, in order to use the image plane to combine the image with other image planes, the new memory page can be single-timed from the other memory pages previously used to create the image plane of the image. It can be switched by a slot command.

  According to a preferred embodiment, the radio tag is configured for processing an image whose image plane has the following meaning: first or second frequency of image content change; first of image content Or second color; first or second information category of image content. Therefore, an implementation suitable for each field of use of the system can be realized, and a combination of plane meanings is also possible here. Also, there can be more than two image planes, for example three, four or five image planes.

  According to such a preferred embodiment, the system realizes an electronic price display system, and the display unit of the wireless tag can be used for displaying product information or price information.

  In each case where a display unit is used, the display unit is realized using, for example, LCD technology, preferably also electronic ink technology (also called E-Ink, which is synonymous with electronic paper). Is possible.

  According to a further aspect of the system, the wireless tag is configured to switch from the sleep state to the active state at a wake-up time having a lead time before the appearance of the synchronized data signal. This measure may be that the entire radio tag, in other words, all parts of that radio tag that are required to receive and process the synchronized data signal are fully operational and therefore may not be significantly evaluated. It is ensured that partial reception of high synchronization data signals is avoided.

  In this case, the lead time period can be selected to be the first small portion of the time slot period of the time slot. The lead time may be, for example, between 0.1% and 10% of the time slot period.

  According to a further aspect of the system, the wireless tag is configured to enter the active state during a reception period that is longer than the transmission period of the synchronized data signal. The advantage with this procedure is that it is guaranteed that the entire synchronized data signal can be received reliably. The reception period that should be used at present can be set to be fixed in a synchronized state with respect to each reception method. However, based on the time-base drift of the RFID tag confirmed based on the appearance of the synchronized data signal, the active period is dynamically adapted to each drift, possibly including the lead time described above. It is also possible. The reception period can also be limited by detecting the loss of the synchronized data signal.

  In order to guarantee optimized reception conditions, in such a system, the RFID tag maintains the active state entered for reception of the synchronized data signal, including the tracking period after reception of the synchronized data signal. It is also possible to be configured as such. This follow-up period is defined, for example, in a predetermined period of the active state, or can be dynamically adjusted depending on the current drift state or reception state.

  In this case, the period of the follow-up period can be selected so that the follow-up period is the second small part of the time slot period. The period of the tracking period may be between 0.1% and 10% of the time slot period, for example. The period of the follow-up period may be the same as or different from the period of the lead time.

  It has proved particularly advantageous that the communication station is configured to transmit a synchronized data signal at the beginning of each time slot. This measure ensures that the start of the time slot can be confirmed very accurately with respect to the radio tag, and that the correction of the internal time base drift of the radio tag can no longer take place at the beginning of the time slot. And therefore that all further tasks of the radio tag can proceed with the best possible synchronization to the time base of the communication station during each time slot, and the remaining length of the time slot To ensure that it can be used.

  The communication station is configured to embed confirmation period data in the synchronized data signal used to allow the confirmation time at which the wireless tag confirmation data is expected to be set during a time slot; It has been found that the fact that the wireless tag is configured to transmit confirmation data at a specified time is advantageous with respect to a communication method that is as systematic and flexible as possible between the communication station and the wireless tag. This is particularly advantageous when a plurality of wireless tags are addressed in one time slot and an individual confirmation time is transmitted to each wireless tag. Thus, for example, each wireless tag can execute a command after receiving a synchronized data signal, switch to an energy-saving sleep state, and switch to an active state again only after a confirmation time determined individually for the wireless tag. The wireless tag confirmation data can be transmitted, and then switched to the sleep state again as soon as possible. Therefore, the determination of the confirmation time performed in the synchronized data signal is a measure for improving the energy efficiency of the wireless tag and a measure for avoiding an impact, and thus has a lasting effect on the life of the wireless tag. Acknowledgment data can indicate the absolute time in the time slot measured from the beginning of the time slot or, for example, the sleep duration for a previous event, for example, The end of the synchronized data signal that can be confirmed in the case of the wireless tag or the end of the active state.

  A further aspect of the present invention relates to assignment of a plurality of wireless tags to a plurality of communication stations. In order to obtain as balanced a distribution as possible with respect to the allocation of radio tags and communication stations, the data processing device, for example a server, is configured to determine which radio tags may be connected to which communication stations. It has been found to be advantageous. The basis for this decision may be an existing distribution of connections in the system, which must be optimized in terms of newly added radio tags. However, there may be a fixed connection pattern defined and realized in advance.

  A data processing device, eg, a server, configured to have a wireless tag to terminate an existing connection with a communication station and connect to another communication station, in order to enable a system that is as dynamic as possible Can be advantageous. In this case, the server reacts to the unbalanced distribution of the wireless tags and positively influences the assignment of the wireless tags and the communication stations in order to realize an optimized load balancing. can do.

  This and further aspects of the invention will be apparent from the drawings described below.

The present invention will be described in detail below again based on the embodiments with reference to the accompanying drawings, but is not limited to the embodiments. Here, the same members are denoted by the same reference numerals in the respective drawings. The following is schematically shown in the drawing:
FIG. 1 shows the system of the present invention; FIG. 2 shows the distribution of the radio channel of the system; FIG. 3 shows a block circuit diagram of an electronic price display board; FIG. 4 shows an assembly of images; FIG. 5 shows a first state diagram; FIG. 6A shows a second state diagram; FIG. 6B shows the first data structure; FIG. 7A shows a second state diagram; FIG. 7B shows a second data structure; FIG. 8A shows a third state diagram; FIG. 8B shows a third data structure. FIG. 8C shows a fourth data structure.

  FIG. 1 shows an electronic price display system installed in a retail company building as the system 1 of the present invention for communication according to the time slot communication method. For the sake of clarity, the drawings of the building and its furniture are omitted from the drawing. The system 1 includes a server 2, first and second communication stations 3 and 4 (hereinafter abbreviated as stations), and eight wireless tags 7-14 (hereinafter abbreviated as ESL, which stands for Electronic Shelf Label). Including. The server is placed in the office and is connected to the stations 3 and 4 via a wired communication circuit (LAN) L. Stations 3 and 4 are connected to ESL 7-13 by radio signals. Stations 3 and 4 are attached to various places on the ceiling of the sales room. The ESL 7-14 is attached to the shelf corresponding to the product for which the price and the product information are displayed using the ESL 7-14. The merchandise information is transmitted from the server 2 to the stations 3 and 4, and is individually transmitted from the stations 3 and 4 to the respective ESLs 7-14.

  Each station 3, 4 spans one radio area, and in FIG. 1, the first radio area boundary of station 3 and the second radio area boundary 6 of station 4 are partially shown schematically. In this radio area, there is an overlapping area where the ESL 9-11 is arranged.

  At the start of system operation, the stations 3 and 4 were first activated one after another. Each station 3 or 4 knows a radio channel with channel numbers 3, 5, 8, 9, 10 that is preferred for the operation of the system 1. This is illustrated in FIG. 2 where the various frequency bands 15-22 are represented by channel number K. Frequency bands 15, 16, and 17 can be used for conventional WLAN operation. The frequency bands 18, 19, and 20-22 that are prioritized for the operation of the system 1 correspond to the channel numbers 3, 5, and 8-10, and do not overlap with the WLAN frequency band 15-17. Since the radio channel having channel number 3 was first verified as to whether it was already used by another station, station 3 automatically selected that radio channel 3. When confirming the free radio channel, it is confirmed that the radio channel having the channel number 3 is already in use, and the next free radio channel having the channel number 5 is identified. The radio channel having the number 5 was automatically selected. However, the radio channel assignment can be fixed.

  As soon as the station 3 or 4 is put into the respective radio area, the ESL 7-14 confirms that the radio signal of the corresponding station 3 or 4 is present on one or more radio channels. ESLs 7 and 8 connect to the first station 3. The ESL 12-14 is connected to the second station 4. For ESL9-11, it is confirmed that each station 3 and 4 is available to them. At this time, each ESL 9-11 determines the station 3 or 4 that has confirmed the best reception quality after confirming the reception quality of the radio signal received by the respective stations 3 and 4. This is for establishing a connection with the station 3 or 4 that has confirmed the best reception quality in each radio channel (channel number 3 or 5). However, this decision-making process may be performed at the stations 3 and 4, in which case the stations 3 and 4 check each reception quality of communication with the ESL 9-11 and communicate with each ESL 9-11. Since the situation is more favorable, it communicates with each other about which of the stations 3 and 4 is connected to which of the ESL 9-11. However, since the server 2 is connected to the stations 3 and 4, the decision making regarding the assignment between the ESL 9-11 and the stations 3 and 4 can be transferred to the server 2. Therefore, a radio channel is first selected (also referred to as “channel scan”) within the frame of establishing a connection between the respective ESLs 7-14, and in some cases, after reception quality in each radio channel is evaluated, The unique hardware address of ESL 7-14 is transmitted to the selected stations 3 and 4 for communication. Thereby, each station 3 and 4 knows ESL7-14 allocated to each. This first assignment between the stations 3, 4 and the ESL 7-14 is transmitted to the server 2.

  Next, a second assignment between each ESL 7-14 and exactly one item is made. As a result, the server knows the location of the item shown using the shelves, so which shelf and where on each shelf each ESL 7-14 is in the sales room. ) Know.

  FIG. 3 shows a block circuit diagram of ESL7 as an alternative to ESL7-14, all of which are used in the system. The ESL 7 is a product information realized by a wireless module 24, a processor 25 for data processing, operation state control and function preparation, a memory 26 for storing data and programs, and an electronic ink technology for power saving. And a display unit 27 for displaying. The wireless module 24 is used for communication based on wireless communication with the station 3 or 4, in which reception data is generated from a received wireless signal and transmitted to the processor 25 or transmitted to the processor 25. The transmitted data is converted into a radio signal. Data stored in the memory 26 can be assigned to either the processor 25 or the display unit 27. In addition, what memory type (ROM, EEPROM, RAM, etc.) the memory 26 is, or how the memory 26 is logically or physically allocated to the processor 25 and / or the display 27 is selected. The drawings are not distinguished. In the selected drawing, the indication of connections such as signal lines or data lines between the functional blocks 24-27 and the indication of the energy store (in the case of the present invention a battery) are omitted.

  The image data BD for generating an image using the display unit 27, the hardware address data HAD for designating the hardware address of the ESL, and the parameter data PD regarding the parameter setting of the time slot communication method are stored in the memory 26. In the image data BD, the first image plane of the image is designated by the first plane data ED2, and the second image plane of the image is designated by the second plane data ED2. It must be mentioned that there can be further image planes here.

  The hardware address data HAD includes four bytes B3, B2, B1, and B0, where B0 is the least significant byte of the hardware address data.

  Using the processor 25, different plane data ED1 and ED2 are assembled into an entire image at ESL7. The first and second plane data ED1 and ED2 correspond to one image information of each pixel. However, “transparent”, “background”, or “background color” is defined as specific image information for both image planes. As a result, a single image plane is overlaid on a pixel-by-pixel basis, so that an entire image can be created by superimposing image content at the same coordinates of pixels on each image plane. The image is a bitmap format, but there are other formats such as JPG.

  This image formation is schematically shown in FIG. The first image plane 28 represented through the first plane data ED1 basically contains static image information 29 about the product, and this static image information is changed only when ESL7 is assigned to another product. Is done. The static image information 29 relates to descriptive text related to a product, for example. All other image parts are defined as “transparent”. The second image plane 30 represented through the second plane data ED2 is basically dynamic image information 31 that changes relatively frequently compared to static image information, for example, daily, several times daily, or weekly. including. The dynamic image information 31 relates to, for example, the price of a product or the validity of a discount, such as a start date and an end date or time or other conditions attached to a discount. All other image parts are defined as “transparent”. The entire image 32 represented through the image data BD, formed by overlapping each pixel of the first image plane 28 and a pixel of the second image plane 30 that completely corresponds to that pixel, is a static and dynamic image. The information 29 and 32 and the part with the mark “transparent” remaining between them are shown.

  In the ESL 7, all the field image data BD can be received in a compressed form, decompressed, and placed in the memory 26. This may be done, for example, for the first transmission of all images. However, this method takes a relatively long time and thus causes a relatively high energy requirement. As long as the image exists in ESL7, the partial update of the image is more efficient because it can be performed with energy saving. To that end, the ESL 7 receives each image plane (eg, the second image plane 30) that must be updated separately from other image planes (eg, the first image plane 28) already placed in the memory 26, It can be decompressed and placed in the memory 26. Next, in order to newly form all the images 32, the newly created second plane data ED2 is accessed inside (switched from one memory side to the other memory side).

  The ESL 7 includes a time control stage 33 that may be implemented as an independent hardware element or at least partially implemented using the processor 25. This time control stage 33 generates a time base that is typical for ESL, and uses this time base to control the state timing (transition and termination) of ESL 7. The timing control is performed, for example, using timing parameters that are known per se and / or provided to the processor.

  Hereinafter, the time slot communication method used in the system 1 will be described with reference to FIGS. Here, only ESL 7-9 assigned to the first stage 3 is taken up, but the same description applies to ESL 11-14 assigned to the second station 4. In the state diagram shown in FIGS. 5-8, time t is written on the abscissa. In the ordinate, the respective state Z is described for the elements of the system 2 considered in the description. Thus, this figure shows the time state progression.

  In each of FIGS. 5-8, the uppermost state progress indicates the state of the stage 3 to which the symbol ST is attached. During one time slot cycle period DC (eg 15 seconds), N time slots Z1... Having the same time slot period DS (eg about 58 milliseconds). . . ZN (for example, 256) can be used. During the time slot cycle period DC, stage 3 is switched between transmission state T and stationary state R. The transmission state T is always the time slot Z1. . . Taken at the beginning of ZN and using the respective synchronized data signal SD, the respective time slot symbols ZS1, ZS2,. . . It is held during the synchronized data signal period DSD (or the synchronized data signal SD transmission period DSD) for transmitting the ZSN. Each time slot symbol ZS1. . . ZSN includes each time slot Z1. . . The consecutive numbers of ZN are time slots Z1. . . Used according to the order of appearance of ZN. Accordingly, in hexadecimal (with the mark “Hex”), the first time slot Z1 has a time slot symbol Hex 00, the second time slot Z2 has a time slot symbol Hex 01, etc. The slot symbol ZN (the 256th time slot Z256 in this example) is marked with a Hex FF symbol.

  In the following, ESL7-9 is described in hexadecimal notation (the most significant byte on the left = the fourth byte B3: the third byte B2: the second byte B1: the least significant byte on the left = the first byte B0). The hardware address is taken up. The hardware address of the ESL 7-9 is unchanged during the actual operation of the system 1. However, in order to describe various aspects of the system 1 using a foreseeable number of ESLs, different hardware addresses are sometimes given to the ESL of the system 1 depending on the drawings, or one or more ESLs are It may not be included in the explanation.

  In the case of FIG. 5, the hardware address of the first ESL7 is Hex B2: 00: 01: 00, that of the second ESL8 is Hex B2: 00: 01: 01, and that of the third ESL9 is Hex B2: 00: 02: 00. . The fourth ESL 10 is not considered.

  In the case of FIG. 6, the hardware address of the first ESL7 is Hex B2: 00: 01: 00, that of the second ESL8 is Hex B2: 00: 02: 00, and that of the third ESL9 is Hex B2: 00: 03: 00. . The fourth ESL 10 is not considered.

  In the case of FIG. 7, the hardware address of the first ESL 7 is Hex B2: 00: 01: 00. The remaining three ESL8-10 are not considered.

  In the case of FIG. 8, the hardware address of the first ESL7 is Hex B2: 0: 01: 00, the second ESL8 is Hex B2: 01: 00: 01, the third ESL9 is Hex B2: 02: 00: 01, The thing of 4ESL10 is. The fourth ESL10 is B2: 00: 03: 01.

  In the system 1, using the least significant byte B0, each ESL 7-9 checks the time slot that appears in the frame of the time slot communication method assigned to each ESL 7-10. The remaining three bytes B1-B3 of the hardware address except the least significant byte B0 are stored in the time slots Z1. . . Used to individually address ESL7-10 in ZN.

  In FIG. 5, the first ESL 7 is in a more synchronized state. The first ESL 7 switches from the sleep state S at the first wake-up time TA1, and switches to the active state E ready for reception before the appearance of the expected synchronized data signal SD with the passage of a relatively short lead time DV. The synchronization data signal SD is received during the reception period DE having one time slot symbol ZS1 (Hex 00), and the least significant byte B0 of its own hardware address (Hex 00) is compared with the received time slot symbol ZS1. To confirm that the first time slot Z1 allocated to the first ESL7 is displayed (matching byte to be compared: B0 of hardware address and first time slot symbol ZS1), and to define a new wake-up time The parameters of the time control stage 33 used for wakeup control are as follows: Save for wake-up in the next time slot cycle, re-enter sleep state S with a relatively short lead time DN, and when the set sleep state dwell time ends, the new (second) wake-up as planned At time TA2, it occurs at the lead time VD before the new start of the first time stroke cycle Z1. The same applies to ESL8 which is in a synchronized state as in the first ESL7.

  The third ESL 9 is in an unsynchronized state before the synchronization time TSY, and this is indicated only by a broken-line arrow 34 parallel to the time axis. The third ESL 9 occurs at the arbitrarily selected first wake-up time TA1, switches from the sleep state S to the active discharge squad E ready to receive and waits in this state until a new appearance of the synchronized data signal SD is received. In this case, the second time slot symbol ZS2 (Hex 01) is received. The third ESL 9 is based on the least significant byte B (Hex 01) of its hardware address and the time slot assigned to it is already a thing of the past during the current time slot cycle, so the time slot symbol Recognizing that the next time slot with Hex 00 will finally come in the next time slot cycle, then the time slot Z2 that was just confirmed will have one time slot on its original time slot Z1 side. This is referred to as the time slot difference in the following. Therefore, at the third ESL9, the time control stage 33, like the synchronized ESL, the new wake-up time TA2 before the appearance of the first time slot Z1 of the next time slot cycle, the lead time DV Are programmed to separate each other. The dwell period DSA that must be waited when in the sleep state S is calculated as follows: subtract the time slot period DS from the sleep state dwell period (if it is in a synchronized state) Multiply the difference (in this case the value 1). Therefore, the third ESL 9 is in the synchronized state again as only the concept is shown by the continuous line, and after switching from the active state E to the sleep state S, after the end of the dwell period DAS, the new wake-up time TA2 To the active state E again.

  Based on FIG. 6A, addressing ESL 7-9 individually and individually indicating ESL 7-9 with a single time slot command are described. Only the first time slot Z1 embedded between two synchronized data signals SD is shown. The station 3 embeds address data AD, command data CD, and confirmation time data ZD in the synchronization data signal SD of the first time slot Z1. The first ESL7 is based on the address data AD of Hex B2: 00: 01, the second ESL8 is based on the address data AD of Hex B2: 0: 02, and the third ESL9 is addressed based on the address data AD of Hex B2: 0: 03. Is done. Using the command data CD, the “PING” command is transmitted to the first ESL7, the “PING” command is transmitted to the second ESL, and the “SWPAG2” command is transmitted to the third ESL9. This command is a single time slot command that is processed in such ESL7-9, taking a short time immediately after being decoded. The two “PING” commands are used to test whether the addressed ESL 7, 8 responds with the confirmation data ACD, ie whether ESL 7, 8 is present or has responded and synchronized in the first place. The “SWAPG2” command is used to change the image shown using the display unit 27 as described with reference to FIG. 4, for example, to the third ESL9 from the (first) current memory page to the second memory page. Can be switched to. Further, with the synchronized data signal SD, the confirmation time is transmitted by transmitting the first stationary period DR1 for the first ESL7, the second stationary period DR2 for the second ESL8, and the second stationary period DR2 for the third EL9. The reference point for the three stationary periods DR1-DR3 is always the end of the reception period DE. FIG. 6B shows the data structure transmitted using the synchronized data signal SD at the beginning of the first time slot Z1.

  Instead of the single stationary period DR1-DR3, the maximum period of the response that is generated as a result of the sum of each stationary period DR1-DR3 and the period for transmitting the confirmation data ACD may be mentioned.

  According to FIG. 6A, each ESL 7-9 indicates a time slot to which the first time slot symbol Z1 is assigned (since all three ESL 7-9, the least significant byte B0 of the hardware address is Hex 00 Recognize that you are synchronized. Confirmation of the address data AD indicates that each ESL 7-9 is individually addressed (there are three remaining bytes B1-B3 of each hardware in the address data AD), and each ESL 7-9 is designated. The executed command is executed immediately after being decoded, and the individual quiescent period DR1. . . After the end of DR3, the individual confirmation data ACD is transmitted to the station 3 ready to receive the confirmation data ACD during the station reception period SDE. The complete processing of the single time slot command including the communication of the confirmation data ACD is performed during the first part 36 of the time slot Z1, so that the second part 37 is subject to other issues such as multi-time. It can be used to process slot commands, and this is taken up in detail in FIGS.

  FIG. 7A shows the processing of a multi-timeslot command, in which the first ESL 7 completes all data (eg, all of the images that must be shown) over three adjacent timeslots Z1-Z3. (Or only one image plane of the image) into three data packets DAT1. . . The data is received from the station 3 while being divided into DAT3. The first ESL 7 uses the synchronized data signal SD to recognize the synchronized state of the first ESL 7 and that it is individually addressed (address data Hex B2: 00: 01: 01), and between the time slots Z1 to Z3. The three data packets DAT1. . . Receives and decodes the “DATA_INIT” command used to instruct the first ESL 7 to receive DAT3, and enters the sleep state S at the end of the reception period DE for the first waiting period DW1, and the first waiting period DW1 is a time slot. It ends at the end of the first half of period DS. At the beginning of the second part 37 of the first time slot Z1, the station 3 enters the transmission state T and the first ESL 7 is ready to receive the first data packet DAT1 during the data transmission period DT. The active state E is entered. Thereafter, the first ESL 7 uses the partial confirmation data ACD1 to confirm reception success during the confirmation period DA in which the station 3 is also in the reception state E. The confirmation period DA ends before the end of the first time slot Z1. After the confirmation period DA is over, the first ESL 7 remains in the sleep state S during the second waiting period DW2 which continues until the end of the first part 36 of the second (next) time slot Z2. At the beginning of the second part 37 of the second time slot Z2, the station 3 enters the transmission state T and the first ESL 7 is ready to receive the second data packet DAT2 during the data transmission period DT. The active state E is entered. The same applies to the third time slot Z3, the end of which is the end of data transmission. Each data packet DAT1-DAT3 successfully transmitted is confirmed using the partial confirmation data ACD1-ACD3. The data structure transmitted at the beginning of the first time slot Z1 using the synchronized data signal SD is shown in FIG. 7B.

  Based on FIG. 8A, data transmission using a combination of one multi-timeslot command and three single timeslot commands is described. The first ESL 7 is synchronized with the first ESL 7 using the synchronized data signal SD (the least significant byte B0 of the hardware address is Hex 00) and is individually addressed (address data Hex B2: 00) : 01) and three data packets DAT1. . . Receives and decodes a “DATA_INIT” command used to instruct the first ESL 7 to receive DAT3. A data structure transmitted at the beginning of the first time slot Z1 using the synchronized data signal SD is shown in FIG. 8B. Data transmission from the station 3 to the first ESL 7 continues as described in FIG. 7A.

  The second time slot symbol Z2 indicates the time slot assigned to ESL8-10 (the least significant byte B0 of the hardware address is Hex 01 in all three ESL8-10), so the three remaining ESL8 -10 recognizes that ESL 8-10 is synchronized at the beginning of the second time slot. As described with respect to FIG. 6A, confirmation of address data AD indicates that each ESL 8-10 is individually addressed (in address data AD, there are three remaining bytes B1-B3 for each hardware. ), The commands specified in the respective ESL8-10 (in this case, three “PING” commands) are executed immediately after being decoded, and are also executed in individual quiescent periods DR1. . . After completion of DR3, individual confirmation data ACD is transmitted to station 3. The data structure transmitted at the beginning of the second time slot Z2 using the synchronized data signal SD is shown in FIG. 8C.

  As can be clearly seen, the first part 36 of the second time slot Z2 for the single time slot command and the second part 37 of the second time slot Z2 for the multi time slot command are reserved for the necessary data communication respectively. Thus, the three single time slot commands and the one multi time slot command are handled almost simultaneously with respect to the time unit “time slot” in the second time slot T2. However, the assignment of each command type to the time slot portions 36, 37 can be reversed.

  Finally, it should be pointed out that the drawings described in detail above are merely examples that can be modified in various ways by those skilled in the art without departing from the scope of the invention. As pointed out for completeness, the use of the indefinite article "ein" or "eine" does not exclude that there may be more than one applicable feature.

Claims (35)

The wireless tag (7-14) is configured to communicate with the communication station (3, 4) using a time slot communication method, and in a repetitive sequence, a plurality of time slots ( Z1-ZN) is provided for the communication, and each time slot (Z1-ZN) is assigned a unique time slot symbol (ZS1-ZSN) in the radio tag (7-14). ,
The communication station, for the current time slot (Z1-ZN), at the start of each said time slot (Z1-ZN), the synchronized data signal (SD1-ZN) containing its time slot symbol (Z1-ZN) )
The wireless tag (7-14)
+ At wake-up time (TA1), switch from sleep state (S) to active state (E),
+ Receiving the synchronized data signal (SD) in the active state (E),
+ Only identifying the time slot symbol (ZS1-ZSN) that appears at the time predicted by the radio tag or in the forecast period and indicates the time slot (ZS1-ZSN) specified for the radio tag By confirming the synchronization state between the wireless tag and the communication station (3, 4),
+ Received time slot symbol (ZS1-ZSN) is to display the radio tag (7- 14) to the specified time slot (Z1-ZN), the subsequent time slot cycle of the current time slot cycle, A new wake-up time (TA2) corresponding to the next occurrence of the designated time slot (Z1-ZN) is defined, and after the wireless tag (7-14) confirms the synchronization state, it again enters the sleep state. The wireless tag (7-14) configured to switch until a wakeup and a switch from sleep state to active state are performed again at a new wakeup time in the next time slot cycle .   When the received time slot symbol (ZS1-ZSN) displays the time slot (Z1-ZN) specified in the wireless tag (7-14), the synchronized data signal with respect to the included address data (AD) The wireless tag according to claim 1, wherein the wireless tag (7-14) is configured to evaluate (SD) and confirm whether the wireless tag (7-14) is individually addressed. Tag (7-14).   When a plurality of wireless tags (7-14) are addressed using address data (AD), one or a plurality of other addressed wireless tags (7-14) are evaluated in addition to their own address And the time corresponding to the turn determined based on the confirmed address in the group of the addressed wireless tags (7-14) within the period designated for transmission of the confirmation data (ACD). The wireless tag (7-14) according to claim 2, wherein the wireless tag (7-14) is configured to transmit its own confirmation data (ACD).   The radio tag (7-14) is configured to generate and transmit partial confirmation data (ACD1-ACD3) in each time slot (Z1-Z3) in which a multi-timeslot command is executed. The described wireless tag (7-14).   Each of the adjacent adjacent first portions of the respective time slots (Z1-ZN) after the received data packet (DAT1-DAT3) and before the end of the respective time slot (Z1-ZN). The radio tag according to claim 4, wherein the radio tag (7-14) is configured to transmit partial confirmation data (ACD1-ACD3) to the second part (37) of the time slot (Z1-ZN). Tag (7-14).   Check whether the synchronized data signal (SD) can be received several times over a period that coincides with the period of the time slot cycle, in particular, over a period extended in a part of the period, and the synchronized data signal (SD) 6. The wireless tag (7-14) according to any one of claims 1 to 5, wherein the wireless tag (7-14) is configured so as to switch the wireless channel (18, 19, 20-22) if it does not come and execute the reception confirmation again. The described wireless tag (7-14).   Search for synchronized data signal (SD), a group of pre-designated radio channels (18, 19, 20-22), in particular radio tags (7-14) connected to the communication stations (3, 4) 7. The wireless tag (7-14) is configured to be limited to wireless channels (18, 19, 20-22) that have been transmitted by the communication station (3, 4) beforehand. The wireless tag (7-14) described in 1. A display unit (27) for displaying the image (32) is included, the image (32) is structured into image planes (28, 30), and each image plane (28, 30) is image plane data (ED1, ED2). The wireless tag (7-14) receives the image plane data (ED1, ED2) individually and assembles the image (32) by superimposing the image planes (28, 39). Configured,
The wireless tag (7-14) so that the communication station (3, 4) transmits each image plane data (ED1, ED2) in the communication of the entire time slot using the wireless tag (3, 4). 8) The wireless tag (7-14) according to claim 1, wherein the wireless tag is configured. + Receiving at least one new image plane (28, 30) of the image (32);
+ Replace the existing image plane (28, 30) of the image (32) with the just received image plane (28, 30) to create a new appearance image,
The wireless tag (3, 4) according to claim 8, wherein the wireless tag (3, 4) is configured to change an existing image (32). In the image plane (28, 30) the following meanings:
The first or second frequency of image content change, or
The first or second color of the image content, or
The first or second information category of the image content,
10. The wireless tag (7-14) according to claim 8 or 9, wherein the wireless tag (7-14) is configured to process an image (32) to which is provided.   The switching from the sleep state (S) to the active state (E) is performed using the lead time (DV) before the appearance of the synchronized data signal (SD) at the wake-up time (TA1, TA2). The wireless tag (7-14) according to any one of claims 1 to 10, wherein the wireless tag (7-14) is configured.   The radio tag (7-14) according to claim 11, wherein the lead time (DV) is a first part of a time slot period (DS) of the time slot (Z1-ZN).   The radio tag (7-14) is configured to enter an active state (E) during a reception period (DE) longer than a transmission period (DSD) of a synchronized data signal (SD). 13. The wireless tag (7-14) according to any one of 12 above.   The wireless tag (7−) is configured to continue the active state (E) that has been entered to receive the synchronization data signal (SD) by using the follow-up period (DN) after reception of the synchronization data signal (SD). 14. The wireless tag (7-14) according to any one of claims 1 to 13, wherein 14) is configured.   15. The wireless tag (7-14) according to claim 14, wherein the tracking period (DN) is a second part of a time slot period (DS) of the time slot (Z1-ZN). -A plurality of time slots (Z1-ZN) are provided for communication per time slot cycle in a repeated sequence, and each time slot (Z1-ZN) is given a unique time slot symbol (ZS1-ZSN). A system (1) including a communication station (3, 4) for communicating with a plurality of wireless tags (7-14) using a time slot communication method,
  The communication station, for the current time slot (Z1-ZN), at the start of each said time slot (Z1-ZN), the synchronized data signal (SD1-ZN) containing its time slot symbol (Z1-ZN) )
  -The wireless tag (7-14)
  + At wake-up time (TA1), switch from sleep state (S) to active state (E),
  + In the active state (E), receive the synchronized data signal (SD),
+ Only identifying the time slot symbol (ZS1-ZSN) that appears at the time predicted by the radio tag or in the forecast period and indicates the time slot (ZS1-ZSN) specified for the radio tag By confirming the synchronization state between the wireless tag and the communication station (3, 4),
  + When the received time slot symbol (ZS1-ZSN) displays the time slot (Z1-ZN) specified in the wireless tag (7-14), in the time slot cycle subsequent to the current time slot cycle, Define a new wake-up time (TA2) corresponding to the next occurrence of the specified time slot (Z1-ZN),
  After the wireless tag (7-14) confirms its synchronization state, it switches to the sleep state again, where again the wakeup and the switch from the sleep state to the active state are the new wakeup in the next time slot cycle. A system that is configured to stay in place until it is executed at the time.   If the received time slot symbol (ZS1-ZSN) displays a time slot (Z1-ZN) not designated in the wireless tag (7-14), the wireless tag (7-14) is designated as the designated time slot. If (Z1-ZN) appears in the current time slot cycle, or if the specified time slot (Z1-ZN) no longer appears in the current time slot cycle 17. A new wake-up time (TA2) corresponding to the next occurrence of the designated time slot (Z1-ZN) is defined between subsequent time slot cycles of the current time slot cycle. The system (1) described in 1.   The wireless tag includes a storage stage (26) for storing parameters of the time slot communication method, and the wireless tag (7-14) accesses and evaluates this parameter for definition of a new wake-up time (TA2). The system (1) according to claim 16 or 17, which is configured as follows.   The wireless tag (7-14) includes a storage stage (26) for storing an indication of a time slot symbol (ZS1-ZSN) representing the time slot (Z1-ZN) assigned to the wireless tag. The system (1) according to any one of -18.   The above indication of the time slot symbol (ZS1-ZSN) is constructed using the hardware address of the wireless tag (7-14) that uniquely identifies the wireless tag (7-14), and the storage stage is unchanged. The system (1) according to claim 19, wherein a program is entered in (26).   21. The system (1) according to claim 20, wherein the indication of the time slot symbol is realized by the least significant bit or the least significant byte of the hardware address.   The radio tag is configured to check whether a time slot symbol known by the radio tag matches a time slot signal when receiving a synchronized data signal. The system (1) described in 1.   23. The communication station is configured to generate a time slot symbol as a consecutive number of each time slot in response to appearance in time slot order during a time slot cycle. (1).   The communication station (3, 4) is configured to embed address data (AD) in the synchronization data signal (SD), and using the address data (AD), the wireless tag (7-14) A plurality of wireless tags (7-14) can be individually addressed per one time slot (Z1-ZN) specified in
  -The wireless tag (7-14) contains the address included when the received time slot symbol (ZS1-ZSN) displays the time slot (Z1-ZN) specified in the wireless tag (7-14). 24. Any one of claims 16 to 23, configured to evaluate the synchronized data signal (SD) with respect to the data (AD) and to check whether the corresponding radio tag (7-14) is individually addressed. The system (1) according to paragraph 1.   The communication station (3, 4) receives one or more bits or bytes (B3, B2, B1) of the hardware address of the wireless tag (7-14) that uniquely identifies the no-new tag (7-14). The system (1) according to claim 24, wherein the system (1) is configured to generate address data (AD), in particular, omitting the least significant bit or the least significant byte (B0).   The communication station (3, 4) is configured to embed command data (CD) in the synchronization data signal (SD), and using the command data (CD), the wireless tag (7-14) During the time slot (Z1-ZN) specified in 1 can be sent to one wireless tag (7-14),
  -The wireless tag (7-14) includes a command included when the received time slot symbol (ZS1-ZSN) displays the time slot (Z1-ZN) specified in the wireless tag (7-14). 26. System (1) according to any one of claims 16 to 25, configured to evaluate a synchronized data signal (SD) with respect to data (CD) and to execute a command.   The wireless tag (7-14) evaluates the command data (CD) and executes the command when the wireless tag (7-14) is individually addressed using the address data (AD). 27. System (1) according to claim 26, configured.   The wireless tag (7-14) is configured to execute the command as a single time slot command and complete the executed command within the single time slot (Z1-ZN) that received the command. Item 28. The system (1) according to item 26 or 27.   -When completing the command being executed, the wireless tag (7-14) generates confirmation data (ACD) in the time slot (Z1-ZN) that received the command and transmits the confirmation data (ACD). The system (1) according to claim 28, configured as follows.   The radio tag (7-14) is configured to transmit confirmation data (ACD) in the first part (36) of the time slot (Z1-ZN), the first part (36) Is positioned subsequent to the synchronized data signal (SD), and the continuation of the time slot (Z1-ZN) before the synchronized data signal (SD) of the next time slot (Z1-ZN) appears. System (1) according to claim 29, wherein the system (1) does not touch the two parts (37). 28. System (1) according to claim 26 or 27, wherein the radio tag (7-14) is configured to execute one command as a multi-time slot command over a plurality of time slots (Z1-ZN). 28. The system (1) realizes an electronic price display system, and the display unit (27) of the wireless tag (7-14) is used as a display of product information or price information. System (1). The communication station (3, 4) is configured to transmit a synchronized data signal (SD) at the beginning of each time slot (Z1-ZN). System (1). The communication station (3, 4) is configured to embed the confirmation period data (DR1-DR3) in the synchronization data signal (SD), and using the confirmation period data (DR1-DR3), the wireless tag The confirmation time in the time slot (Z1-ZN) where the confirmation data (ACD) of (7-14) is expected can be determined,
  The system (1) according to any one of claims 16 to 33, wherein the radio tag (7-14) is configured to transmit confirmation data (ACD) at the time. A plurality of communication stations (3, 4), a plurality of wireless tags (7-14), and the wireless tag (7-14) are terminated with the existing connection of the communication stations (3, 4) to other communication stations ( 35. The system (1) according to any one of claims 16 to 34, comprising an information processing device (2) configured to be connected to 3, 4).

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