SK10295A3 - Method of transmitting measurment data - Google Patents

Abstract

Described is a system for remotely reading out data from a multiplicity of measurement units (10), the system operating by radio transmission at a single frequency. The various measurement units (10) deliver their sets of data within stochastically selected time windows of short duration. In this way, the measurement units can have simply designed circuitry and can be operated over very long periods from long-life batteries.

Description

(57) ¹ Annotation:

The method of remote reading of a plurality of measuring units (10) is performed by radio transmission at a single operating frequency. The various measuring units (10) transmit their records in randomly predetermined small-width time windows to the evaluation unit (16). In this way, it is possible to make the measuring units (10) easy to operate, which are operated for a very long time by batteries (28) with a long lifetime.

Measurement data transmission method

Obiasťtechnky

The invention relates to a method of transmitting measurement data from a plurality of measurement units to a central evaluation unit, in which the measurement units connect the data transmission path to the evaluation unit at different times.

BACKGROUND OF THE INVENTION

In practice, such methods of transmitting the measured data are carried out by transmission cables arranged between the central evaluation unit and a plurality of measurement units associated therewith. A multiplexer is provided in the evaluation unit, which at a given time connects one of the measuring units to the input / output interface of the evaluation unit.

acceptable deductions

For many applications, such data transmission is not applicable, either because the distances between the measuring units and the central processing unit are too large, or because the installation of different data transmission cables is not due to the high costs or loads involved One example of this embodiment is a remote appliance in existing buildings. In this case, it would be very necessary for the various meters of water, gas, oil, electricity, heat, etc. appliances to be read. , which are installed in different residential units of the house in different places, without access to individual measuring points. The reading of the measuring instruments is associated with high personnel costs, especially since it is impossible to reach anyone during the day in most single-person households.

In those cases. if the design of an additional installation of data transmission lines is excluded, wireless data transmission could be considered. However, there is a problem that the radio frequencies are only available to a very limited extent and, moreover, the modem receiving components required for each transmission channel are too expensive. However, for the remote reading of appliances measuring instruments, one important requirement is that the cost of data transmission does not in any way exceed the cost of actually collecting the measured data.

Now transmit measuring quantities measuring the number of such cases in remote reading only a relatively small data transmission of one

Because of the transmission periods it was found that the large measured data. in particular appliance appliances, relates to data. The time periods required for the units may be of the order of several 10 ms. In this case, it is then possible to have all the measuring units transmitted on one common operating frequency, the individual measuring units being associated with randomly distributed narrow transmission windows. Then, a single evaluation unit can be used for all units of measurement, the receiving part of which is tuned to a common operating frequency.

in the above short individual to perform a very large number of time intervals per day (several million), there is a likelihood that two units of measurement (out of a total of 100 to 1000 units that are, as usual, required to read appliances in residential complexes) at the same time, very small. A small number of overlaps of data records transmitted from different measurement units simultaneously are recognized in the evaluation unit and the respective signal sequences are discarded.

SUMMARY OF THE INVENTION

The aforementioned drawbacks are eliminated by the method of transmitting the measured data from several measuring units to a central processing unit, in which the measuring units are connected at various times by a data transmission path with an evaluation unit according to the invention. together with the identification signal characterizing the measuring unit, it assembles into one record, the measuring units transmit their records at random predetermined moments on the same operating frequency, and the evaluating unit sorts out those received corresponding to the overlapping records from the received signal sequence further evaluation takes the signal sequences remaining after this sorting, which correspond to a single record.

The method of data transmission thus performed can be carried out with low technical costs.

Based on the constellation that is typical for remote reading of appliances in a residential block, a 20 mW RF transmission power is sufficient, which corresponds to an operational wattage of about 200 mW. The short transmission times, which are of the order of 10 ms, therefore result in such a low overall power consumption that it is possible to use long-life batteries for the operation of the measuring units, usually for 10 years. Therefore, the capability of the radio data transmission capability is comparable to the calibration periods of the measuring units, so that it is quite sufficient to completely replace these measuring units in periods of time usually after about 10 years.

Further advantageous solutions according to the invention in the dependent claims.

are listed

According to claim 2, they only broadcast.

is the measured data when it is up to some of the last transmitted measured data. Thus, from the measuring point, the measurements have changed with respect to, for example, the measurement units of the heat consumers in the summer, in which it is not heated, completely dispensing the measured data for weeks. This extends the usable time of the batteries supplying the metering unit.

When transmitting data, it is known that 2 own data to be transmitted can additionally be calculated according to a predetermined algorithm a control number or one control bit, which is guided along the data path along the transmission path. At the end of the reception, the control number can then be calculated by 2 of its own data, which is compared with the transmitted control number. If both check numbers match, the data transfer was correct. In the method of claim 3, this checking method is simply used to determine the overlap of records, since the time overlap of records transmitted independently from different measurement units produces an overall sequence of signals with a completely different bit structure which corresponds to a substantially logical sum of the two individual structures. If the time offset between the two sub-bit structures is large, the check number detected by the evaluation unit at the end of the entire sequence belonging to the time later bit structure does not match all previously received data. With only a small time offset, there will be no control number at all at the end of the entire sequence, or a check number that does not belong to a previously transmitted data sequence.

According to a further preferred embodiment according to claim 4, it is possible first to observe the timing of the measurement data generation, and second, it can be deduced from the fact that for a particular unit of measurement that the last received measurement data has been performed long ago. to malfunction.

In the method according to claim 5, it is also guaranteed for a long time that the timing of the measurement data to be loaded is correct in time.

In the embodiment according to claim 6, an additional possibility of fault detection is provided. For example, for measuring units of appliances, the control criterion may be that the measured data transmitted increases monotonically. Transmitting measured data that is smaller than the last correctly measured data indicates a fault. However, it is possible to compare the record received by 2 one measuring point not only 2 of the same measuring point, with the previously transmitted records being compared with the records of 2 other measuring points, if there is a factual link. If, for example, in a building complex 2 transmitted records of other measuring units show that the heat consumption is generally stagnating (eg due to the heating off) and in a single measuring unit, according to the transmitted records, the heat consumption is increasing significantly despite the failure of the measuring unit or that its installation is faulty.

According to claim 7, the resulting faults in the evaluation unit can be stored and stored for later evaluation for fault elimination.

A further embodiment according to claim 8 is advantageous in view of increasing the security of data transmission.

By means of this, the generators transmitting another advantageous embodiment according to that in a simple manner using random numbers, random times of different measuring units are obtained.

of claim 9 with identical distributions

In doing so, the embodiments used in accordance with claim 10 also eliminate the possibility of a completely possible identical choice due to identical random number generators or their algorithms. The last or last two decimal places of the measured values may be used as an uncontrollably changing physical variable in a measuring instrument with maximum resolution.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in greater detail below with reference to the drawings, in which the consumption figure shows a block diagram of heat in a complex of buildings, a metering device. FIG. 1, and a computer development diagram of a control program that is evaluated by the evaluation unit of the device of FIG. 3 and 4 always show a block diagram of a modified embodiment of the apparatus on in a complex of buildings.

similar to FIG. 1, heat consumption measurement

The measuring unit 10 shown in FIG. 1 shows one heat consumption which, at irregular intervals by a transmitting antenna 12, a record having the following block, the measured data (state at this time), the identification

For the measurement above and the composition, the start mark of the heat appliance counter data (number and, if applicable, the type of measuring unit), the end mark of the block. This data can be converted into a RF signal packet with a duration of about 10 ms in a typical heat consumption measuring unit 10.

The RF signal packet is captured by the receiving antenna 14, which is associated with the evaluation unit 16 arranged in the building complex at a location accessible for reading. The evaluation unit 16 demodulates the RF signal packet, checks it, and stores the heat consumption data for the measurement unit in the associated memory area (RAM, or direct input memory and / or hard disk), as will be described in more detail later.

The metering unit 10 is an independent unit which is not dependent on the mains electricity and which is located on the heating element of the dwelling unit of a building complex or is assigned to a meter of hot water consumption for this dwelling unit.

Further, a plurality of other measuring units 10-i are disposed at other locations of the building complex, of which in FIG. 1 only one. Typically, the number of these measuring units 10-i cooperating with the evaluation unit 16 may range from 20 to 1000 pieces.

The measuring unit 10 is provided with a temperature sensor 18 which is thermally connected to the associated appliance. The non-volatile memory 20 stores the identification signal of the unit 10, for example in the form of a number assigned to the unit 10.

The computation circuit 22 integrates the output signal of the temperature sensor 18, optionally evaluating it in a predetermined manner, and composing the measured consumption value signal with the identification signal from the nonvolatile memory 20 and the block start and end blocks in one record.

The recording prepared by the computing circuit 22 is further sold to a memory 24, which in the considered embodiment is activated to store data around midnight.

For this purpose, the clock module 26 of the measuring unit K connected to the first clock circuit 28 is programmed! at 24.00, the output terminal of which is connected to the memory control terminal 24.

The output signal of the first clock circuit 28 further activates the random number generator 30. The random number generator 30 receives three input signals, namely the contents of the non-volatile memory 20, the output signal of the temperature sensor 18 reduced by the rounding circuit 32 to the last places after the decimal point, and finally its respective own output signal. From these three signals, the random number generator 30 calculates a set of transmission times randomly distributed throughout the day according to a predetermined algorithm. In the exemplary embodiment contemplated herein, it is assumed that 6 transmit times per day are required, the mean distance is therefore 4 hours.

Six transmission times are prepared for the clock switching circuit 34, which is additionally provided by the clock module 26.

exit for the second receives the time of day

If the current calculated by the generator matches the 30-hour switching circuit 34 of the transmitting circuit 36.

time of day with transmission times of random numbers, activates the second

The transmitter circuit 36 is connected on one hand to the memory 24 and, upon activation, always receives one complete record with the composition described above, starting block mark, measured data, identification data, block end mark, converts this record into a serial representation and module using the serial bit structure of the output signal of the RF generator belonging to the transmitter circuit 36, and in FIG. 1, not shown, which has a transmitting power of about 20 mW and operates in the higher MHz range or in the lower GHz range.

Power to the transmitter circuit 36 is provided by a long-life battery 38 which can provide the power of about 200 mW required to operate the transmitter circuit 36 for the aforementioned short transmission periods for approximately 10 years.

On the other hand, the power supply of the electronic logic clock circuits 28, 34 of the metering unit 10 is effected by means of a long-life battery which is schematically connected, without its connection to the individual clocks. 1 2 depicted individually shown by the switching circuits 28. 34

So that information about it can be sold to the consumer. which data is transferred from the measuring unit 10 to the evaluation unit 16, the display unit 42 is also connected to the output of the memory 24.

The evaluation unit 16 has a receiving circuit 44 which demodulates and forms the signals received by the receiving antenna 14. The current generated by these signals is applied to the computer input

46, which performs data evaluation according to the flowchart, and storing the received measured measurements shown in FIG. Second

The computer 46 checks the feed current generated from the signals first for the presence of the initial block marker. If it detects such an initial block marker, it is scanned until it is a block.

the following signals are detected end mark

From the thus obtained control bit is separated. Z calculates a control number, which is then compared with the transmitted control number. If the two control numbers do not match, the program returns to the starting point of the program.

the markings of the measured eye are separated and then given

If these two check numbers match, the computer 46 retrieves from the read / write memory 48 associated with it.

and which may be a sufficiently large RAM or hard disk or floppy disk, one or more previously transmitted measurement data records stored there, which according to the identification signal belong to the received measurement data record.

In the next block, the new measurement data record is now subjected to a sense check, which for measuring the heat consumption can for example simply consist in checking whether the new value of the heat consumption is greater than the last stored value. For complicated use, a sense check may also be based on testing whether the measured value record just received represents a continuous and meaningful further development of a larger number of previously received records.

In the sense check, it is possible to add records received from other units of measurement 10-i when their signals are materially related.

If the record just received satisfies the sense check, this record is compiled with the time prepared by the clock module 50 of the computer 46 and stored in a read / write memory array 48 adapted for the measurement unit 10 under consideration.

In practice, this field may consist of only a few memory cells, but preferably at least as many memory cells that are sufficient for the records to be transmitted by one measuring unit 10 per day.

As a rule, the read / write memory 48 is read out once a day from a master main terminal (not shown) via modem 52. For example, the modem 52 may be a TEMEX unit.

Unless otherwise the correct record fails the sense check, this record is also stored together with the time of day in the fault memory 56.

which is also designed as a memory for and read out with the read / write memory 48 from the central main terminal, the resulting faults draw conclusions about the respective corrections or read / write, via modem 52, which then from the installation improvements. In practice, the read / write memory 48 and the fault memory 54 may be sub-memories 1.

parts of a single big one

For local inspection and maintenance of the computer 46, a keyboard 56 and a monitor 58 may be attached to the computer 46, for example in the form of a laptop computer.

From the above description of the device, it is evident that the device is entirely in the direction of the evaluation unit of the units 10-i

It is therefore necessary in FIG. 1, it is sufficient to arrange the costly receiving circuit 44 once without transferring the data 16 to the various measurement practices.

Detection of measured data, although individual measurement units 10-i differ due to manufacturing inaccuracies

However, it is not necessary to set the local time in the individual measuring units 10-i in the above-described method of transmitting the measured data to the evaluation unit 16.

First of all, from which to

In the embodiment of FIG. 3 is a measurement. units 10, 10- and further simplified, always based on the current transmission time, calculates a single following transmission time according to the principle of randomness, then another transmission time, which in the considered arbitrary example of the four-hour embodiment also transmit circuit 36 is also directly connected with the output of the moment lying within the current transmission time.

computational circuit 22.

In another modified device of FIG. 4, an additional memory 60 is connected to the output of the memory 24, which always receives the last measured data record transmitted (C = clock and terminal, 1 = data input, 0 = data output). The outputs of memories 24 and 60 are coupled to inputs of comparator 62, which prepares the output signal when both input signals differ by more than one predetermined value, which can be set, for example, at potentiometer 64. Between the output of the second clock circuit 34 and the control a transceiver 36 is inserted as a new member 66, the second input of which is connected to the output of the comparator 62. In this way, activation of the transceiver 36 stops as long as the measured data is not substantially altered.

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Claims (2)

A method of transmitting measurement data from a plurality of measurement units (10) to a central evaluation unit (16), wherein the measurement units (10) at different times connect the data path to the evaluation unit (16), characterized in that a) in the measuring unit (10) the measured data to be transmitted together with the identification signal characterizing the measuring unit (10) is compiled into one record, (b) the units of measurement (10) transmit their records at random at predetermined times on the same operating frequency by radio, c) the evaluation unit (16) sorts the signals corresponding to the overlapping records from the received signal sequence at the operating frequency and, for further evaluation, assumes the signal sequences remaining after this sorting, which correspond to a single record. Method according to claim 1, characterized in that the measurement units (10) store the last transmitted measurement data and the random determination of the next transmission time is performed or activated only when the current measurement data differs by more than one from the last transmitted measurement data a predetermined value. Method according to claim 1 or 2, characterized in that the measurement units (10) calculate a control number from the measured data transmitted according to a predetermined algorithm and supply a corresponding control signal to the measured data and thus create an extended record that the evaluation unit (16) separates the control signal from the extended records, calculates the control number from the measured data according to the same predetermined algorithm, and stores the downloaded record only if the control number corresponding to the transmitted control signal and the calculated control number matches. Method according to one of Claims 1 to 3, characterized in that the evaluation and unit (16), together with a record found to be correct, stores the time of day in which the record was received. Method according to claim 4, characterized in that the clock module (50) of the evaluation unit (16) is set at intervals to normal time. Method according to one of Claims 1 to 5, characterized in that the evaluation and unit (16) compare the correctly transmitted record with at least one of the previously received records according to predetermined criteria and store them only after the new record satisfies these criteria. Method according to claim 6, characterized in that the evaluation unit (16) maintains a record of records not meeting these criteria and stores these records, in particular together with the time of their receipt and the type of failure to meet these criteria. Method according to one of Claims 1 to 7, characterized in that the measuring units (10) store the measured records at regular intervals and always provide a plurality of randomly distributed transmission moments between the storage times. Method according to one of claims 1 to 8, characterized in that the determination of the random transmission moments is carried out by a random number generator (30), based on the number of outputs characteristic of each measuring unit (10). Method according to claim 9, characterized in that the determination of random transmission moments additionally depends on uncontrolled variables. where physical is performed List of reference numbers measuring unit 10, 10-i transmit antenna 12 receiving antenna 14 evaluation and unit 16 temperature sensor 18 non-volatile memory 20 computing circuit 22 memory 24 clock module 26 first clock circuit 28 random number generator 30 rounding circuit 32 second clock circuit 34 Transmitter circuit 36 Long life battery 38 Display unit 42 Receiver circuit 44 Computer 46 Memory read / write clock module 50 Modem 52 Memory 54 Fault keypad 56 Monitor 58 Additional memory 60 Comparator 62 Potentiometer 64 Product element 66 fv 402.- pv 402.-35 I. 2/4