FR2633797A1 - Method and device for the remote reading of meters - Google Patents

Abstract

The subject of the invention is a method and a device for transmitting figures from meters or other numerical information. It consists of modules 1 located in the homes of customers whose meter is to be read. The module, via a microcontroller 2, copies the figures from the meter(s) 3 and, at a previously determined instant, using the customer's telephone line 4 if it is free, calls a central computer 5 attached to the telephone network and transmits to it, via a slow but reliable and inexpensive coder 6, the information contained in the memory. The central computer receives the figures and transmits to the microcontroller, via a decoder 7, the date of the next reading.

Description

METHOD AND DEVICE FOR REMOTE SURVEYING
AT A PROVISIONED MOMENT OF COUNTERS
The subject of the invention is a method and a device for transmitting meter indexes or other encrypted information in which the data is transmitted to a central computer by a telephone line at a predetermined instant and in which the data is stored in parallel. transmitting.

There are known such devices which have the disadvantage of requiring the installation of a particular telephone line for each set of meters located in the same customer. On the other hand, the transmission systems used are expensive if you want good reliability because they use complex protocols.

The subject of the invention is a reliable and inexpensive system.

According to the invention, the method is characterized in that the DTMF system (Dual Tone Multifrequencies) is used for the transmission of
Information and in that the customer's usual telephone line is used automatically at a predetermined date and time to call the central computer.

The method is also characterized in that the central computer can also call up the data of the indexes in memory.

The corresponding device is characterized in that it comprises, from the indexes of the counters to be read, a microcontroller which periodically interrogates the sensors indicating the index changes, delivers on preprogrammable dates and times a message to a decoder which transmits the index and addresses by the customer's telephone line to the central computer which decodes this information to record it in its memories and receives from the central computer, by a decoder connected to the microcontroller, instructions relating in particular to the date and the time of the next change in the form of a time to count down.

DETAILED DESCRIPTION OF THE SYSTEM
I - Counting sensor: The simplest system adaptable to counters with a roller timer consists of sticking a magnet inside a roller and a reed contact embedded in the timer so that when the loving the contact closes.

For a complete revolution of the roller, i.e. N counting units (N = 1 or 10X or I 10X), the Reed contact goes through two states, one open,
The other closed.

The index of the counter is copied into RAM as follows
- The microcontroller for row i counting emits a positive pulse on the pin connected to the sensor T. and examines the RC pin where the returns of all the counts result. If the contact is closed, the pulse emitted on T. is found on pin RC.

 - After recognizing the state O or F of the reed contact, the microcontroller examines the state of the indicator Ei relative to the counter i placed in RAM.

If the contact is open
or E. = O then E. remains = O
or E. = 1 then E. goes back down to O
If the contact is closed
or E. = 1 then E. remains = i
or E. = O then Ei goes up to 1 and the index li is incremented.

II
Any other counting unit sensor system can be adapted to return to the previous scheme.

2 - Triggering Robot Calls - Server 2.1. The basic module is designed so that cist the robot which
at the request of the server, on a date, at a time,
programmed at the second near during the previous connection
Robot - server (Vacation).

It is intended that, to avoid overlapping of calls, a broad
30 second call scheduling spacing for
a 10 to 15 second shift allowing two vacations per
minute or nearly 1,000 readings in an 8 hour night by
server.

This wide difference between calls is calculated according to the
probable drift of the crystal oscillators of the modules.

These can be installed outdoors even with a quartz
precision the influence of temperature variations is kept
quente.

Robots-Releve are normally connected to the TV line
private telephone of the customer with whom they are installed. The vacations
as long as the line is free at a pro hour
grammed so that the probability of use at this
instant of the line by the customer is neglected (generally the
night).

The moment when the next shift should occur (at the second
meadows) is calculated by the server which can correct the drift of
quartz due to temperature. The server simply issues the
number of seconds which must separate the end of the current shift
of the next shift. This number works as an "hourglass"; he
is decremented each time the microcontroller is woken up.

 When the hourglass is empty, an indicator is placed in RAM.

When this indicator is read during the program, the pro
cessus vacation is triggered.

In addition, an "Emergency call" pin is tested each time
wake up of the microcontroller. When this pin is at + 1 a
status indicator is placed in RAM triggering the second following
touts the Vacation program.

2.2. Robots-Relève can also be installed on a line
having a particular call number allowing them to be
called directly by the server.

To do this, a call from the server of 1 second triggers, by the
ringing current, an emergency call which in turn triggers
the shift as soon as the server is hung up. This assembly allows
make the "Returnable" module simple.

2.3. All the modules can finally operate in "Manual". A bou
your push button installed on the box triggers an emergency call.

 This initializes a vacation.

3 - Operation of Releve Robots.

Each module essentially comprises
A telecom interface,
A DTMF encoder and a DTMF decoder,
A micro-controller,
A precision oscillator.

 The last two components are permanently on.

The oscillator activates the microcontroller every second. The latter during each awakening examines the indicators previously placed in RAM to know the operation to be performed.

 The microcontroller outside the holidays tests the sensors placed on the meters to which it is connected.

 During the vacation period, he activates the telecom interface.

 Connecting the interface powers up the interface and the DTMF coder-decoder system, all of which are supplied with power from the telephone network during the entire shift. These last two CIs connected by a 4-bit data bus to the microcontroller allow the server-robot dialogue in hexadecimal code. The 6 letters of this code are used for instructions or addresses.

MicrFcontroller program: Starting from a standby state, the microcontroller is reactivated every second by a pulse delivered by the precision oscillator counting down the elapsed time.

The microcontroller then performs the following checks
Examination of the pins and storage of indicator S - Initialization if + I program Initialization - Emergency call if + 1 do S2 = 1 - Line test if + 1 do 53 = 1 - Data arrival if + 1 do Sg I
Examination of indicators in memory (RAM) If 5i + 1 - hourglass program ~ S2 if + I - line request program - 53 If + 1 - server call program - 54 if + 1 - dialogue program - S if + l - program counting
The different programs run according to the state of the indicators in memory.

Initialization program: A battery-powered device connected to the module's internal circuits by a specially adapted socket allows.

- To set the initialization pin to + 1 - To zero the memories (RAM) of the microcontroller - To enter RAM at their address, digit by digit, the following numbers
Module N, server telephone n, index and value N.

Then the indicator S1 is set to + 1 thus authorizing the running of the other programs
Hourglass program: It is triggered by Si = 1 I. This program decrements the hourglass and N numbers in RAM. If the balance of N is equal to zero Sg is set to +1. If the balance of the hourglass number is zero S2 is set to 1 and S1 to zero.

Line request program: It is triggered by S2 = 1 An output of the "Line request" microcontroller is set to + 1; it validates the electronic circuit verifying the absence of communication on the line. If the answer is positive, the "Line test" pin goes up to 1. This implies that S3 will be set to 1. Sg is set to 1.

Server Call Program: 11 is triggered by S3 = 1. S2 is set to zero. The "Line seizure" pin is set to + 1. A pin of the microcontroller emits n pulses which cut the line n times for each digit of the server call number. The number n is equal to the value of the digit of the telephone number in question unless this digit is 0 in which case n = 10. The times of line break, of holding between the cuts of a digit between each digit comply with the rules of the telecommunications service of the country in question.

 S3 is set to zero and S5 to 1. An elapsed time counter (watchdog) is put into operation.

Dialogue program: If the server picks up and responds to the module by sending it an instruction, the "Data arrival" pin goes up to + I and the S4 indicator goes up to I in RAM. This program notes the value of this indicator when the previously scheduled time (1 to a few seconds) has elapsed.

- If 54 = O the line is rendered by the line taken pin which descends to zero.

- If S4 = I the microprocessor examines the data present on the bus. These are letters defining an operation code - The first code instructs the module to emit the following values contained in memory
Module number, counting index is set to I and an elapsed time counter is again armed - The second code precedes a number of 8 digits maximum indicating the number of seconds at the end of which a vacation must be triggered (hourglass).

After receiving the 8 digits the module re-transmits this hourglass value to the server then S5 is set to 1 and an elapsed time counter is armed.

- The third code orders the closing of the session.

 is set to 1, S4 has gone back to zero as well as the "Line seizure" pin.

Counting program: It is triggered by the reading of Sg = 1. For each counter sensor connected to the module, the micro-controller goes up to 1 the sensor input and reads the common feedback. The index of this counter is incremented as previously indicated in the paragraph on the counting sensor.

After reading all the counts the microcontroller goes to sleep after having made S5 = O and authorized the interruptions.

Observations: It should be noted that the counts are read in a time of the order of a few milliseconds. The microprocessor is thus active for a fraction of time significantly less than 1/100.

During a vacation, the program runs so that several "counting" programs are inserted during the exchange of module-server information. The voice frequency transmission system allows a speed of the order of 10 digits per second.

For 10 counts the emission of these indexes lasts approximately 8 seconds; there will be no "counting" during these 8 seconds.

If this time seems too long, it is easy to modify the dialogue program. A first code will force the module to transmit its number plus a certain number of 8-digit indexes. A second code will force the emission of the other indexes. In addition, it is possible in this same spirit to plan remotely the modification of the 8-digit call number of the server station. We have for the codes usable in the dialogue program in a very simple way of 6 codes is the 6 letters ABCDE F. One code is reserved for sending the hourglass number, another for the end of vacation order, it remains 4 codes to send or modify the values in memories.

Finally, it is remarkable that the simple dialog program ensures all the desired reliability because the server can re-issue such code which it would not have understood the return of transmission. The module can be re-read as many times as desired by the server and if there is a problem or lack of time the server can simply issue a low hourglass value plus the FIN code so that the next day a new shift occurs.

The system designed is very flexible and allows many variations of use.

Server program: The server listens permanently or during the periods scheduled for vacations according to the chosen system and in particular if emergency calls are accepted.

The server is connected to a line whose number is stored in the modules. This line can be used by the server, and another person, provided that there is an off-hook on each call
The electronic board of the servers is identical to that of the modules except for the micro-controller. The latter is replaced by a data acquisition card connected either to a microcomputer or to a more powerful computer existing in the service responsible for the use of meter readings. Sc; ma 3.

With each call the ringing current allows the closing of a relay which takes the telephone line and activates the computer. The latter issues a letter, code recognized by the robot to initiate the module's dialogue program, which first addresses the robot's number. This number includes at the head of the message a letter of the hexadecimal code. Yes
The computer does not recognize this code because it is not a module, it "hangs up", stil recognizes the code, it records the module number. This number is characteristic of the second he must call and it specifies the number of 8-digit indexes he has to transmit.

The computer thus has any means of control at its disposal to manage the shift appropriately according to a preset program. It puts the indexes received in memory with the module number, the precise vacation time. After sending the hourglass number and sending the FIN code, the computer goes back to standby.

Claims (3)

1 - Method for the transmission of the indexes of gas or electricity meters and others in which the data is transmitted to a central computer by a telephone line and in which the data to be transmitted is stored beforehand, characterized in that one uses the DTMF system for the transmission of information and in that the line used is the customer's usual telephone line to which one automatically connects at predetermined dates and times. 2 - Method according to Claim I characterized in that the central computer can call according to a known process and be answered and receive the data delivered by the counting indexes. 3 - Device according to Claims 1 and 2 comprising counter indexes to be read, characterized in that it comprises a microcontroller which periodically interrogates the sensors giving changes to the indexes, delivers a message relating to its address at predetermined dates and times. the index situation, and receives from the central computer the date and time of the next reading in the form of a number of seconds to count down. - An encoder receives the information from the microcontroller in the form of a dual voice frequency signal (DTMF) to transmit it by the customer's telephone line to the central computer where this information is decoded and stored in its memories. - A DTMF decoder connected to the microcontroller receives the signals transmitted by the central computer.