EP0789333A2 - Franking machine - Google Patents

Abstract

The arrangement includes a printer for printing a post value stamp (10) on the mail item, a central control (30) for controlling the printing and peripheral components (42 to 46) of the postage meter, a billing unit (60) for deducting a postage, and at least one non-volatile memory (68, 70) for storing postage data. The billing unit accesses the postage data according to a predetermined control program (AS1 to AS8), and is implemented as a digital electronic circuit arrangement. The control program of the billing unit is predetermined in form of electronic gates connected permanently with each other, and a number of gates is realised on at least one user-specific building block (66) as integrated circuit.

Description

The invention relates to a franking machine for franking mail, with a printer for printing a postage stamp on the mail, a central control for controlling the pressure and peripheral components of the franking machine, a billing unit for billing postal charges, and with at least one non-volatile memory for storing Postage fee data, wherein the accounting unit accesses the postage fee data according to a predetermined control program, and wherein the accounting unit is implemented as a digital electronic circuit arrangement.

In known franking machines (cf., for example, US 4,675,841; EP 0 665 518 A2), a central microprocessor controls the franking process in such a way that billing takes place first in the accounting unit and then the postage stamp is printed on the mail item. The postage data is changed during billing. The postage data is mostly stored in a descending and an ascending register. The value of the descending register is reduced by the accounting unit for each franking operation by the value of the postage stamp to be printed, starting from a starting value. The value of the ascending register is increased by the value of the postmark to be printed. The accounting unit changes the postage fee data by executing a predetermined control program, which is stored as a command sequence centrally in a program memory designed as a read-only memory. The control program is processed by a further microprocessor contained in the processing unit.

If only the billing unit accesses the postage fee data, known protective measures consist in housing the billing unit and the memory for the postage fee data in a security module that is difficult to access from the outside. Casting the security module further complicates mechanical interventions in the accounting unit. In order to protect the accounting unit from electronic interventions, it has been proposed to use optocouplers at the interface of the security module (see, for example, US 4,301,507 or DE 30 40 559 C2). However, the known measures do not offer sufficient protection if the command sequence in the program memory of the processing unit is changed, e.g. by manipulating the content of the program memory from the outside.

Postage meter machines are also known, in which a printer monitor for the optional transfer of print data to the printer is included in the security module depending on monitored sizes (for example EP 0 513 880 A2). Printer monitoring is controlled by a third microprocessor, which processes a printer control program. The printer control program is in turn stored as a command sequence centrally in a printer program memory. The known protective measures fail if the command sequence in the printer program memory is changed.

In known franking machines, the accounting unit and printer monitoring are connected to a module bus consisting of signal lines. The accounting unit of the printer monitoring signals, among other things, successful accounting via this module bus. If the above-mentioned measures are avoided, the module bus and in particular the signal line mentioned is exposed and the signal flow can be interfered with from outside.

The object of the invention is to provide a franking machine with increased security, in which in particular each printed postage stamp is countered by a monetary value corresponding to the postage value.

This object is achieved for a franking machine of the type mentioned at the outset in that the control program of the accounting unit is specified in the form of firmly linked electronic gates, and in that a large number of gates is implemented on at least one user-specific component as an integrated circuit.

The invention is based on the knowledge that it is much more complex to modify a control program which is specified in the form of firmly linked electronic gates (for example AND gates, OR gates, NOT gates) and thus does not require an instruction memory and instruction counter. as a command sequence stored in a central command memory in the form of a ROM. Such a command memory and also the necessary programming device are in fact readily available commercially, so that the command sequence stored at a central point in the computing unit can be manipulated. A control program according to the invention, which is predetermined in the form of firmly linked electronic gates, so that the control program in space and time in the gates distributed, however, can only be changed by removing links, inserting links or gates. It is therefore considerably more complex and practically impossible to change the control program if a large number of gates are implemented as an integrated circuit on a user-specific component. Reprogramming by changing the links is not possible because the block is destroyed by the mechanical intervention. Since the module is user-specific, it cannot be purchased in stores. If the control program in the franking machine according to the invention is to be changed, a new integrated circuit must be produced. This includes the design, the test and a complex manufacturing process. The manufacturing costs are all the more important since the cost ratio for user-specific modules is inversely related to the number of pieces. Such user-specific modules are also known under the name ASIC.

The control program of a postage meter machine according to the invention is implemented exclusively by gate modules without using a central command memory which is at risk of manipulation. Also a command counter, an address bus, an address control, etc., i.e. Blocks for the operation of a microprocessor system are not required to execute the control program for the accounting.

The franking machine with the accounting unit according to the invention is therefore implemented in such a way that each printed postage stamp is countered by a monetary value corresponding to the postage value, since the accounting data are changed in the manner described above before the postage value is printed before each printing of a postage stamp and only paid fees are stored as postage data.

In one embodiment of the invention, the printer monitor transmits print data in accordance with a printer control program, which is also specified in the form of firmly linked electronic gates and which is preferably implemented with the accounting unit in a single integrated circuit. This measure is based on the consideration that the printer control program and the connections between the printer monitor and the accounting unit must also be protected against external interference. This also results in the effects mentioned for a monitoring unit designed according to the invention for printer monitoring.

By combining the accounting unit and the printer monitoring in a single integrated circuit, both units are equally protected in the exemplary embodiment according to the invention. Feeding signals into the connecting lines between the accounting unit and printer monitoring for the purpose of unauthorized manipulation is excluded, since these lines are part of the integrated circuit and can therefore only be exposed by destroying the circuit. Protection is increased if the integrated circuit is housed in an encapsulated housing. The encapsulation can e.g. can be reached through a closed steel cassette, to which only persons authorized by Swiss Post have access.

If the housing and thus the user-specific component is cast with a chemically resistant and mechanically difficult-to-remove casting compound, direct access to the accounting unit, the memory for the postage fee data and the printer monitoring is prevented even after the housing has been removed. If sensors are arranged in the potting compound, removal of the potting compound can be recognized. In particular, temperature sensors, humidity sensors and pressure sensors are used. If one of these sensors registers a removal of the sealing compound, the sequence control of the accounting unit and / or the printer monitoring is blocked. The franking machine can only be operated again after the blockages have been released by one of the post authorized person or a service technician possible.

In a further exemplary embodiment, the printer monitoring system activates a transmission unit when an enable signal which is generated by the accounting unit signals that accounting has been carried out. Since the accounting unit of the invention can no longer be changed in its mode of operation, an enable signal is only generated if the accounting has actually been carried out. Since the release signal also runs on a line in the integrated module that is not accessible from the outside, it is ensured that the printing of the postage stamp is offset by a corresponding monetary value. Only when the release signal has been generated is the transmission unit activated so that a printing process can begin at all. If a clock generator for generating a print clock signal and a control unit for controlling the printer are only activated by the pressure monitor when the release signal is present, this results in a threefold protection which prevents printing without an release signal.

If the print data transmitted to the printer is counted during printing and compared with a predetermined number of transmitted print data, a blocking signal can be generated which prevents the accounting unit from recalculating postal charges. The number of transmitted print data is determined so that the lock signal is generated as soon as the first parts of the postage have been printed. In this case, the mail is considered franked. On the one hand, this measure gives the operator of the postage meter machine a longer period of time to cancel a print that has started and, on the other hand, prevents partial franking from being carried out and then the back calculation being carried out.

By generating a blocking signal after a predetermined number of transmitted print data, can be prevented be that an unreasonably long printed image in the form of a chain of smaller fee images is continuously printed after a settlement.

The object of the invention set further above is further achieved by a franking machine with the features of patent claim 15. The protective effect is increased in this franking machine, since internal connecting lines of an integrated circuit cannot be accessed from the outside without destroying the integrated circuit. The security of this franking machine is further improved if the internal bus system between the accounting unit and the printer monitoring is already protected by the use of the integrated technology. This type of connecting line provides greater protection both in the case of a control program which is processed by a microprocessor and is stored in a command memory, and in the case of a control program which is specified in the form of firmly linked electronic gates.

Figur 1

ein auf Postgut zu druckendes Druckbild,

Figur 2

ein Blockschaltbild mit wesentlichen elektrischen Funktionseinheiten einer Frankiermaschine,

Figur 3

ein Blockschaltbild eines Sicherheitsmoduls,

Figur 4

ein Blockschaltbild einer Abrecheneinheit,

Figur 5

eine Darstellung der Hierarchie von Ablaufsteuerungen für die Abrecheneinheit,

Figur 6

ein Blockschaltbild einer Druckerüberwachung,

Figur 7

ein Flußdiagramm der Arbeitsweise der Abrecheneinheit, und

Figur 8

ein Flußdiagramm der Arbeitsweise der Druckerüberwachung.

An exemplary embodiment of the invention is described below with reference to the drawings. Show:

Figure 1

a printed image to be printed on mail,

Figure 2

2 shows a block diagram with essential electrical functional units of a franking machine,

Figure 3

a block diagram of a security module,

Figure 4

a block diagram of an accounting unit,

Figure 5

a representation of the hierarchy of sequence controls for the accounting unit,

Figure 6

a block diagram of a printer monitor,

Figure 7

a flowchart of the operation of the accounting unit, and

Figure 8

a flowchart of the operation of printer monitoring.

In Figure 1, a print image 10 is shown, which on postal items, e.g. on paper of an envelope, is printed with a franking machine according to the invention. The printed image 10 consists of a postage stamp image 12, a date stamp image 14 and an advertising image 16. The upper right corner of the printed image 10 can be selected as the origin of an xy coordinate system, which at the intersection of a horizontal x-axis designated x and one designated y vertical y-axis.

The postage stamp image 12 shows a postage value 18 of DM 1.00. The date stamp image 14 shows the current date on which the printed image 10 is printed on the mail item, and a text element "advertising" is displayed in the advertising image 16 for advertising purposes.

The printed image 10 is composed of pixels corresponding to the xy coordinate system. The pixels form columns with a length of 240 pixels in the y direction. Pixels lying one below the other in the y direction are combined to form a byte, so that 30 bytes form a column. A column A is defined by an x position in which pixels of the postage value 18 appear in a column for the first time as the x value increases. Thus column A denotes a column-by-column printing of the printed image 10 starting with the x value zero, the first column which contains pixels of the postage value 18.

A column B is located at an x position that lies behind the highest x value of a column for the advertising image 16. Column B has an x value, which characterizes the maximum length in the x direction of the printed image 10.

FIG. 2 shows a block diagram of the franking machine with essential electrical functional units. A central microprocessor 30 controls the printing of the printed image 10, which is printed using a printer 32. The microprocessor 30 is connected via a control bus 34, which contains address, data and control lines, to a security module 36, which in turn is connected to the printer 32. The microprocessor 30 is thus not directly connected to the printer 32, but exclusively via the security module 36. The structure of the security module 36 is explained below with reference to FIG. 3.

Furthermore, the microprocessor 30 is connected via the control bus 34 to a non-volatile memory 38 and a working memory 40. A central control program for the central microprocessor 30 is stored in the memory 38 as a command sequence. Templates for compiling the printed image 10 are stored in the memory 38. The microprocessor 30 loads the desired template into the working memory 40 and processes the template according to the inputs of an operator. After these entries, which also include the entry of the postage value 18, the desired print image 10 is generated and stored in the working memory 40. However, the non-volatile memory 38 does not contain any instruction sequences for billing postage.

Using a keyboard 42 connected to the control bus 34, the operator can operate the franking machine and, for example, that Specify print image 10. A display 44 controlled by the microprocessor 30 informs the operator of the processes in the franking machine.

An input / output unit 46 connected to the control bus 34 is connected to drive elements (not shown) of the franking machine and to sensors which monitor the state of the franking machine. The transport system (not shown) for transporting the mail item is also connected to the input / output unit 46.

Figure 3 shows a block diagram of the security module 36. The security module 36 is located in a closed housing which is filled with a potting compound. This also makes access to an accounting unit 60 contained in the security module 36 and a printer monitor 62 more difficult. The security module 36 also contains an interface 64, via which it is connected to the control bus 34. Printer monitor 62 transmits print data provided by microprocessor 30 at interface 64 to printer 32.

The accounting unit 60, the printer monitor 62 and the interface 64 are implemented on a user-specific module 66 as an integrated circuit. The billing unit 60 carries out a billing of postal charges corresponding to the postage value 18 before each franking operation. The postage fee data are stored in duplicate in two non-volatile memories 68 and 70 in registers REG 0 to REG 3. Registers REG 0 to REG 3 each contain a descending and an ascending register.

In the franking process, the microprocessor 30 requests a billing before printing the printed image 10. For this purpose, the microprocessor 30 transmits the postage value 18 via the control bus 34, the interface 64 and a module bus 72 to the accounting unit 60. The accounting unit 60, its mode of operation 4 and 5, explained below, is connected to the memories 68 and 70 via a memory bus 74. Depending on the postage value 18, the accounting unit checks whether billing is possible by comparing the postage value 18 with the current value of the descending register in register REG 0. If the permitted value range is exceeded arithmetically, for example by virtue of the fact that a positive remaining credit as the current value in the descending register would be reduced to a negative remaining credit, the security module 36 is blocked. Consequently, only a postage value 18 that is less than or equal to the remaining credit can be billed. In this case, the accounting unit carries out the accounting by subtracting the postage value 18 in each of the registers REG 0 to REG 3 from the value of the descending register and adding it to the value of the ascending register.

After the accounting has been carried out, the accounting unit 60 issues an enable signal F, which is transmitted to the printer monitor 62 via an internal bus 76. The connecting lines of the bus 76 are implemented exclusively as internal connecting lines of the user-specific module 66 and are located inside the user-specific module 66.

The printer monitor 62, the structure of which is explained below with reference to FIG. 6, only enables printing if the release signal F is present. Only in this case can the pixels of the print image 10 be transmitted as print data in succession from the microprocessor 30 via the interface 64 and the printer monitor 62 to the printer 32.

The unauthorized access to them is made more difficult by the implementation of the accounting unit 60 and the printer monitor 62 in the user-specific module 66. Since the bus 76 between the accounting unit 60 and printer monitor 62 in the user-specific module 66 is realized, it is not accessible from the outside.

The security module 36 contains a microprocessor μP which implements a sequence control AS10 and which processes a program stored in a read-only memory 77 (ROM) as a command sequence. The read-only memory 77 is designed as an internal ROM in the microprocessor μP. After the programming process, a readout lock is set in the microprocessor µP by blowing out a readout channel. Such microprocessors µP are also known under the name OTP processor (ONE TIME PROGRAMMABLE).

With the help of the sequence control AS10 it is possible to reload the postage fee data in the registers REG 0 to REG 3 in an authorized manner. Reloading is carried out by an authorized operator who first enters a code key via the keyboard 42. Reloading can also take place via a remote data connection. The sequence controller AS10 is connected to the module bus 72 and can thus control the accounting unit 60 in such a way that it changes the registers REG 0 to REG 3. When reloading, a default amount is added to each of the registers REG 0 to REG 3 to the current value of the descending register. A total value stored in a total register is also increased by the default value. The ascending register remains unchanged.

The microprocessor μP also specifies to the accounting unit 60 via the module bus 72 the number of bytes which are transmitted to the printer 32 until column A and column B are reached. The microprocessor μP takes these values from the read-only memory 77 when the franking machine is started up.

A reset unit 78 sets the module 66 and the sequence control AS10 in a defined starting state after the franking machine has been switched on.

FIG. 4 shows a block diagram of the accounting unit 60. As mentioned, the accounting unit 60 accesses the memories 68 and 70 as an authorized component via the memory bus 74, in which the postage fee data are stored in the registers REG 0 to REG 3. Accordingly, the accounting unit 60 and in particular its control program must be particularly protected. The accounting unit 60 is controlled by a controller 90. The controller 90 contains the control program of the accounting unit 60 in the form of a large number of firmly linked electronic gates. Thus, the accounting unit 60 can execute the control program of the accounting unit without using a central command memory in the form of a ROM. Also a command counter, an address bus, an address control, etc., i.e. Blocks for the operation of a microprocessor system are not required to execute the control program for the accounting. The mode of operation of the control is explained below with reference to FIG. 5.

The accounting unit 60 also contains an operation unit 92, which contains an adder 94. The operation unit 92 is controlled by the controller 90 and adds or subtracts the postage value 22 contained in a postage register 96 to a register value taken from one of the memories 68 or 70. The respective state of the accounting unit 60 is stored in a status register 98. The control 90 connects the control bus 34 or the module bus 92 to the memory bus 74 via a multiplexer 100. However, memories 68 and 70 can only be read via control bus 34 for service purposes.

The controller 90 is connected to the internal bus 76, so that, on the one hand, control signals are transmitted to the printer monitor 62 when the control program of the controller 90 is being processed and, on the other hand, signal states are also taken into account when the control program is being processed that are generated by the printer monitor 62.

FIG. 5 shows a representation of the hierarchy of sequential controls AS1 to AS8 of the controller 90, the arrows indicating that the sequential control from which the arrow originates is superior to the sequential control to which the arrow points. The controller 90 contains the control program, which is specified in the form of firmly linked electronic gates. The implementation of the control program in the form of gates is carried out as follows: starting from a flow chart of the control program, the linkage of the electronic gates is determined in a circuit design. The control program is divided into sections for which the design process was carried out individually. The result of the design process is a plurality of, in the present case eight, circuit arrangements, each of which realizes one of the sequential controls AS1 to AS8. The circuit arrangements of the sequential controls AS1 to AS8 are implemented on the module 66 in integrated technology, so that subsequent changes to the gate links and thus the control program are excluded, which increases the security of the franking machine against unauthorized manipulation. An essential technical feature is that the sequence controls AS1 to AS8 do not access a central command memory, for example a ROM. Rather, the necessary commands that perform the control function are distributed among a large number of gates that are permanently linked to one another. These gates are distributed over the integrated circuit, ie a change in commands requires an intervention in the gates distributed over the surface, which is practically impossible. Another characteristic of the sequential controls AS1 to AS8 is the lack of a central control unit for processing commands.

The sequential controls AS1 to AS8 are sequential circuits which change their switching states depending on a clock signal in the manner predetermined by their combination.

The sequential controls AS1 to AS4 form the superordinate control of the controller 90 and thus the accounting unit 60. The sequential controls AS5 to AS8 carry out the specific calculation of the data for the registers REG 0 to REG 3 and the control of the memories 68 and 70. Only one of the sequential controls AS1 to AS8 is active at any time. Each sequence controller AS2 to AS8 is triggered by a special start signal from a higher-level sequence controller, e.g. the AS1, starts and reports the completion of its task with a special end signal. If a sequential control system AS2 to AS8 is active, the higher-level sequential control system waits for this end signal.

The sequence controller AS1 is a higher-level controller for the sequence controllers AS2 to AS8. Depending on the accounting task “accounting” or “recalculation” specified by the microprocessor 30, the sequence controls AS2 to AS8 are activated in a sequence predetermined by the sequence controller AS1.

The sequential control system AS2 controls the updating of the four registers REG 0 to REG 3. For this purpose, depending on the accounting task, it activates either the sequential control systems AS3 or AS4 four times in succession. The sequence control AS3 controls the billing, in which the postage fee data is updated before the printing process. The sequence control AS4 controls a back calculation, in which the printing process is interrupted prematurely and the registers REG 0 to REG 3 are reset to their value before the last settlement.

The sequence controller AS3 or AS4 activates the sequence controller AS5 when calculating or back-calculating, in order to calculate a single one of the registers REG 0 to REG 3. Because the register REG 0 to REG 3 each contain eight bytes, the sequence controller AS5 activates the sequence controller AS6, which can calculate a byte, exactly eight times in succession, so that each byte is calculated. The sequence controller AS6 in turn activates the sequence controller AS7, which reads a byte from the memory 68 or 70, in order to calculate a byte. After the calculation has been carried out in the operational unit 92, the sequence controller AS8 is activated by the sequence controller AS6 and writes a byte into the memory 68 or 70.

FIG. 6 shows a block diagram of the printer monitor 62. The printer monitor 62 contains a print release control 110, which is likewise specified in the form of permanently linked electronic gates, and forms a sequence control AS9. The sequence control AS9 monitors the printing process in that it only enables printing when the accounting unit 60 has carried out the accounting and sends the release signal F to the print release control 110 via the bus 76. Only after the release signal F has been applied does the print release control 110 enable the transfer of print data from the control bus 34 to the printer 32, by activating a transfer unit 112 which contains a shift register which transfers the print data serially to the printer 32. The print data are provided by the microprocessor 30 and transmitted to the printer 32 via the security module 36. During this transmission, the microprocessor µP of the sequence control AS10 does not intervene.

The printer monitor 62 also contains a clock unit 114 for generating the print clock. The print cycle is in turn activated by the print release control 110 in that the print cycle is transmitted to the printer 32. A counter / comparator unit 116 counts the transmitted pixels of the printed image 10. When column A is printed, the counter / comparator unit 116 generates a blocking signal S which is transmitted to the accounting unit 60 via the bus 76. The blocking signal S prevents back calculation in the accounting unit 60. When column B is printed, the counter / comparator unit 116 generates a blocking signal, which leads to the printing process being interrupted immediately and the safety module 36 is deactivated so far that only an authorized operator can release the blocking.

FIG. 7 shows a flowchart of the mode of operation of the accounting unit 60. After switching on, the controller 90 is set in a defined start state by the reset unit 78. In a step 132, the controller 90 waits until the postage value 22 is written into the postage register 96 by the microprocessor 30 (step 132). If the postage value 18 is present in the postage register 96, billing takes place in a step 134, in particular by activating the sequence control AS3.

If the billing cannot be carried out because the postage has already been completely used up, this is signaled to the microprocessor 30 and the franking process started is ended (step 138). If the billing could be carried out in method step 134, the release signal F is generated in a step 140, which is transmitted via the bus 76 to the print release control 110 of the printer monitor 62. In a method step 142, activation of the sequence control AS4 is made possible, so that the postage fee data can be recalculated.

As long as a back calculation is possible (step 144), the settlement can be reversed at the request of the microprocessor 30 (step 146). If there is such a request, the calculation is carried out in a step 148, in which in particular the sequence control AS4 is also activated. The back calculation generates a back calculation signal R, which is transmitted via a line of the bus 76 to the printer monitor 32, which immediately interrupts the printing of the printed image 10 when the back calculation signal R is active. The controller 90 the accounting unit 60 returns to its starting state after generating the back-calculation signal R (step 130).

If the printer monitor 62 signals via a blocking signal S, which is also transmitted to the accounting unit 60 via a line of the bus 76, that the printing of the column A has already been carried out, the sequence controller AS1 no longer activates the sequence controller AS4. The controller 90 of the accounting unit 60 can therefore no longer carry out recalculation. In this case, the controller 90 returns to its start state (step 130).

FIG. 8 shows a flowchart of the printing process of the printer monitor 62. When the franking machine is switched on, the print release control 110 of the printer monitor 62 is set to its start state (step 160) by the reset unit 78. The print release control 110 can only perform control operations when the release signal F has been generated by the accounting unit 60 (step 162). As soon as the release signal F is generated by the accounting unit 60 after the accounting has been carried out, the printer monitor 62 can process print data (step 164). The print release controller 110 is in a waiting state in which it waits for print data that the microprocessor 30 transmits via the interface 64.

If print data is available, it is transmitted in a step 166 to the printer 42, which begins printing the print image 10. A counter Z is increased with each byte transmitted. The counter / comparator unit 116 checks in a step 168 whether the counter Z has a value which indicates that the printing of column A has already started. If this is the case, the back calculation in the accounting unit is blocked by the printer monitor 62 generating the blocking signal S (step 170). The counter / comparison unit 116 also checks whether the value of the counter Z indicates whether printing of the column B has already started (step 172). Is this the If this is the case, the security module 36 is blocked in a step 174, the franking process being terminated.

If column B has not yet been printed, printer monitor 62 checks whether a backward calculation has already been carried out by evaluating backward signal R (step 176). If the accounting carried out, which generated the release signal F, has been recalculated, the printing is ended and the printer monitor 62 returns to its starting state (step 160).

If there is no back calculation signal R, then a step 170 checks whether a print end signal has already been generated by the microprocessor 30. If this is not the case, the printer monitor 62 is set to a state which corresponds to that of step 166. If the print end signal has been generated, the printer monitor 62 is set to its start state (step 160).

In FIGS. 7 and 8, steps in which the accounting unit 60 and the printer monitor 62 influence one another are double-framed. This coupling of the two units via the release signal F, the stop signal S and the backward calculation signal R means that it is difficult to bypass the accounting unit or the printer monitoring. The steps 130 to 178 shown in the two flowcharts are not implemented by a microprocessor that processes a command sequence stored in a memory, but by changes in the state of an electronic circuit arrangement. In order to change or skip one or more of steps 130 to 178, a new circuit arrangement of the accounting unit 60 and the printer monitor 62 must be implemented. Since the circuit arrangements are integrated circuits, this is only possible with great effort.

The security of the security module 36 is also increased by the fact that the release signal F, the blocking signal S and the backward calculation signal R are exchanged via the internal bus 76, which is likewise implemented in integrated technology on the integrated module 66. External access is only possible if module 66 is destroyed.

Reference list

10th

Printed image

12th

Postage stamp image

14

Date stamp image

16

Advertising image

18th

Postage Value

30th

microprocessor

32

printer

34

Control bus

36

Security module

38

non-volatile memory

40

random access memory

42

keyboard

44

display

46

Input / output unit

60

Accounting unit

62

Printer monitoring

64

interface

66

user-specific component

68, 70

non-volatile memory

72

Module bus

74

Memory bus

76

internal bus

77

Read only memory

78

Reset unit

90

control

92

Operations center

94

Adder

96

Postage Register

98

Status register

100

multiplexer

110

Print release control

112

Transmission unit

114

Clock unit

116

Counter / comparator unit

130

begin

132

Question whether value in the postal register

134

Billing

136

Question whether settlement was carried out

138

Stop

140

Release signal

142

Enable back calculation

144

Question whether back calculation is possible

146

Question whether back calculation is requested

148

Back calculation

160

begin

162

Question whether the enable signal is active

164

Question whether print data is available

166

Increase print counter Z.

168

Question whether counter Z> column A

170

Block back calculation

172

Question whether counter Z> as column B

174

Stop

176

Question whether retroactive accounting is requested

178

Question whether print end is reached

F

Release signal

S

Blocking signal

R

Backward signal

REG 0 to REG 3

register

AS1 to AS10

flow control

Claims (22)

Franking machine for franking mail,
with a printer for printing a postage stamp (10) on the mail,
a central controller (30) for controlling the pressure and peripheral components (42 to 46) of the franking machine,
a billing unit (60) for billing postal fees, and with at least one non-volatile memory (68, 70) for storing postal fee data,
wherein the accounting unit (60) accesses the postage fee data in accordance with a predetermined control program (AS1 to AS8), and
the accounting unit (60) being implemented as a digital electronic circuit arrangement,
characterized by
that the control program (AS1 to AS8) of the accounting unit (60) is predetermined in the form of firmly linked electronic gates,
and that a plurality of gates is implemented as an integrated circuit on at least one user-specific component (66). Franking machine according to claim 1, characterized by a printer monitor (62) which releases the pressure depending on an enable signal (F), the enable signal (F) being generated by the accounting unit (60) after the accounting has been carried out. Franking machine according to claim 2, characterized in that the printer monitor (62) transmits print data to the printer (32) in accordance with a printer control program (AS9) which is likewise specified in the form of firmly linked electronic gates. Franking machine according to one of the preceding claims, characterized in that at least part of the Printer monitoring (62) and the accounting unit (60) is realized in a single integrated circuit (66). Franking machine according to one of the preceding claims, characterized in that the integrated circuit (66) is contained in an encapsulated, preferably encapsulated housing (36). Franking machine according to one of the preceding claims, characterized in that measures are provided which prevent further printing data from being transferred to the printer (32) when the potting compound is removed. Franking machine according to one of the preceding claims,
characterized in that the postage fee data is stored in a descending and / or an ascending register,
the value of the descending register being reduced by this value depending on the value of each postage stamp to be printed, and
the value of the ascending register is increased by this value. Franking machine according to one of claims 2 to 7, characterized in that the printer monitor (62) effectively switches a transmission unit (112) which transmits print data to be transmitted to the printer (32). Franking machine according to one of claims 2 to 8, characterized in that the printer monitor (62) activates a clock unit (114) for generating a print clock signal. Franking machine according to one of claims 2 to 9, characterized in that the printer monitor (62) is a activates the printer (32) depending on the control unit (112) which controls the print data. Franking machine according to one of claims 2 to 10, characterized in that the printer monitor (62) counts the print data transmitted to the printer (32). Franking machine according to claim 11, characterized in that the printer monitor (62) generates a blocking signal (S) after a predetermined number of transmitted print data. Franking machine according to claim 11 or 12, characterized in that the accounting unit (60) prevents a back calculation of postage depending on the blocking signal (S). Franking machine according to one of claims 11 to 13, characterized in that the printer monitor (62) generates a blocking signal after a predetermined maximum number of transmitted data, which preferably prevents further transmission of print data to the printer (32). Franking machine for franking mail,
with a printer (32) for printing a postage stamp (10) on the mail item,
a central controller (30) for controlling the pressure and peripheral components (42 to 46) of the franking machine,
a billing unit (60) for billing postal charges,
at least one non-volatile memory (68, 70) for storing postage data,
and with a printer monitor (62),
wherein the accounting unit (60) accesses the postage fee data in accordance with a predetermined control program (AS1 to AS8) and an accounting carried out to the printer monitor (62) signaled by an enable signal (F) which is transmitted via at least one line (76) which establishes the electrical connection between the accounting unit and the printer monitor,
and wherein the printer monitor (62) is controlled by a printer control program (AS9) which only releases the print after receipt of the release signal (F),
characterized by
that essential electronic circuit elements of the accounting unit (60) and essential electronic circuit elements of the printer monitor (62) are implemented on a single user-specific integrated circuit (66) and that the line (76) is designed as an internal connecting line on the integrated circuit (66). Franking machine according to claim 4, characterized in that at least one of the control programs (AS1 to AS10) is predetermined in the form of firmly linked electronic gates. Franking machine according to claim 15 or 16, characterized in that the printer monitor (62) activates a transmission unit (112) which transmits print data to be transmitted to the printer (32). Franking machine according to one of claims 15 to 17, characterized in that the printer monitor (62) switches a clock unit (114) to generate a print clock signal. Franking machine according to one of claims 15 to 18, characterized in that the printer monitor (62) generates a blocking signal (S) after a predetermined number of transmitted print data. Postage meter according to claim 19, characterized in that the accounting unit (60) prevents a back calculation of postage depending on the blocking signal (S). Postage meter according to one of claims 15 to 20, characterized in that the printer monitor (62) generates a blocking signal after a predetermined maximum number of transmitted data, which preferably prevents further transmission of print data to the printer (32). Franking machine according to one of the preceding claims, characterized in that the franking machine contains a further microprocessor (µP) with an internal volatile working memory and an internal read-only memory (ROM) preferably provided with a readout lock.

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