EP0716398B1 - Interface circuit for franking machine - Google Patents

Description

The invention relates to an internal franking machine Interface circuit according to the in the preamble of Claim 1 specified type.

Franking machines have at least one transport device, Input, storage and display means and a pressure control unit for a printing device on what print patterns toward you this printing device moved to be printed Record carrier prints. Such printing devices, especially for an electrothermal Printing using an ink ribbon or transport devices are equipped with actuators and sensors, which controlled via a circuit arrangement or are queried (US 4,746,234).

Sensors used to transport the record carrier detect, solve, for example Printing process. Other sensors detect that Position of the counter pressure roller or monitor the ongoing printing.

A shaft of the transport device or coil one moved relative to the record carrier Color carrier that transfers the color particles coupled to an encoder, which clock signals for printing control during the printing process provides. All sensors or actuators are directly or indirectly through a special Circuit arrangement with the control unit, in particular a microprocessor control unit, connected.

For a thermal transfer printing process is already from DE 38 33 746 A1 via a control unit actuated switching unit for one Known printhead that contains resistance elements. A selective control with preheating the Resistance elements serves to reduce the Heating power when printing. To control one Printhead becomes energy for each pixel of the printed image provided and a Print pattern on a relative to the ribbon printed on the recording medium to be printed, by removing the ribbon from the paint layer when the associated heating resistor is heated in the print head on the record carrier transfers.

Inkjet printers are also used to frank mail suitable. According to the used Printing principle must the circuit arrangement to the required actuators and sensors adapted become.

An ASIC is known from EP 465 236 A2, which a circuit for pressure control, for engine control and includes for billing. The circuit for pressure control includes a memory for fixed and another for variable data, which with overlay the fixed data. An engine controller is for actuating a motor drive provided depending on the mailpiece feed. A sensor delivering speed signals is standing via the motor controller with the pressure control in Connection. The high is undoubtedly an advantage Tampering security alone results from the limited number of starting points for a manipulation due to the use of a single ASIC. One disadvantage of using one The only ASIC is the lack of usability for different franking machines, which one different pressure control module accordingly a realized franking machine system or Show Poststrasse.

But should different types of franking machines then a variety of must be produced Circuits (ASIC's or / and other components) be provided. Especially the large number of components and circuits then offer starting points for manipulation, if no alternative Effort driven and a security case is used. Differentiate between franking machine types accordingly in shape and equipment of the mail volume to be processed and thus also regarding a different number Sensors and actuators.

This is periodic polling from EP 231 452 A2 of sensors according to a software routine a central processing unit (CPU), preferably a microprocessor known.

The disadvantage of this solution is a high one Computing time due to periodic sampling of the sensors. This disadvantage is exacerbated if it is a particularly time-critical Query. To get to one as quickly as possible To be able to react to a change in state Polling frequency can be selected high. Consequently the microprocessor spends a large proportion its computing time with the query.

In US 5,267,172 there is already a serial Interface proposed in a franking machine been between a microprocessor and an ASIC is arranged and on which Transfer address, command and data serially to the ASIC become. The disadvantage is that time-critical Queries cannot be realized and none automatic work of the interface is what Computing time in the microprocessor binds.

The latter disadvantage also applies a data processing system known from US 5,199,105 to. For a universal asynchronous receiver / transmitter module is there first shift register for outputting the data and a second shift register for reading the data as well as a programmable comparison register proposed, to trigger interrupt when a specific data byte over the serial channel Will be received.

The task is to create an internal franking machine To develop interface circuit which the Avoids disadvantages of the prior art and for a variety of franking machine variants inexpensively is realizable without compromising security against manipulation to diminish.

A subtask is to query the Sensors by the control device of the franking machine or the control of the actuators on the one hand inexpensive and on the other hand to realize less CPU time is tied up.

The object is achieved with the features of claim 1 solved.

The invention is based on the consideration that Adaptability of the electronic control different franking machine types by one Interface circuit internal to the franking machine improve.

Inside a security enclosure is a Microprocessor of a first circuit part in which only security-relevant data are processed, with a second circuit part according to the invention connected in which the remaining data for each the corresponding type of franking machine to be traded. This second circuit part forms an internal franking machine interface to the first circuit part. The internal franking machine is advantageous Interface switching as a system-specific ASIC executed.

It is assumed that to control a electronic printhead and the actuators or Sensor query the microprocessor of the first Circuit part on the second circuit part accesses. The microprocessor non-periodically queried or at data transmitted.

The circuit part for safety-relevant data is the same for all franking machine types educated. The second circuit part (ASIC) for the rest of the data is according to the type of franking machine as an internal interface to the first Circuit part formed.

The second circuit part (ASIC), i.e. the internal franking machine Interface circuit is with send and receive registers for storage data transmitted in parallel and with one Shift register for the series / parallel or Parallel / serial conversion of transmitted data within an actuator / sensor control in the meter and has two lines on the output side, in particular a transmission and a reception line, to the base of the franking machine by means of which within the franking machine serial data between Meter and a register unit in the base become. At the register unit are Base sensors and actuators connected. Sensor signals are in the shift register of the Actuators / sensor control pushed and lie there available in parallel. As a receive register a sensor status register group for parallel data the sensor signals provided at least one sensor. At least one sensor status register and at least one an interrupt control register are with a Monitoring circuit connected to the received Bits of the sensor signals to change the state monitor in order to interrupt the Trigger control unit.

In addition, the franking machine internal Interface circuit to provide a decoder the memory control signals for the actuator / sensor control and within the actuators / Sensors control a first state machine as well as a print data control. The aforementioned Decoder, the actuators / sensors control and the Print data control each contain control or Data register.

Within the ASIC you can query the sensors and the corresponding data for actuator setting in a known manner in parallel form in Status register or provided in the command register become. Are still only advantageous serial interfaces to the base provided by which is a system expansion for a wide range Sensors and actuators according to the different Franking systems is made possible. by virtue of a small number of lines to the base succeed it, therefore, for and for a meter / base separation to create an inexpensive solution.

The state machine implemented in hardware automatically scans the sensors and loads Status register and sets the actuators accordingly the data stored in the command register.

According to the invention is between the control unit (CPU) and status register an interrupt control switched, with the data lines from the status register trained parallel to the control unit (CPU) are. Is that under hardware control Status register has been loaded, the interrupt controller evaluates individual bits. A predetermined one State or state transitions of the individual bits the control unit (CPU) immediately an interrupt request is communicated.

It is envisaged that the actuator / sensor control has a first state machine that does so it is determined that on the one hand by the Sensor unit supplied controlled register unit into the shift register of the actuators / sensor control can be pushed and then called up there in parallel exist that, on the other hand, exist in parallel Data for actuators from command register groups in the shift register loaded in parallel and then serial for supplying the actuators in the base be read out that the actuator / sensor control and the monitoring circuit with the control unit (CPU) are connected to the interrupt control register and the control unit (CPU) is formed are the type of change in the sensor value, due to which an interrupt request is triggered in the interrupt control register preset and an interrupt accordingly execute so that the control unit (CPU) directly into the corresponding sensor handling routine can branch.

The advantage of such a non-periodic query or transmission of data from the Control unit (CPU) interposed interrupt controller is that computing time on the part the control unit (CPU) is saved. Another The advantage is that the control unit (CPU) no longer needs to be told which sensor has changed its value. The information about the The sensor is activated during interrupt processing Control unit (CPU) communicated so that it directly into the corresponding sensor handling routine can branch. The type of change in the sensor value, due to which an interrupt request triggered, can be preset so that next to the sensor itself through the interrupt request also the type of sensor transition is known without the sensor value in the status register to have to query.

Before the interrupt controller is more advantageous Way an interrupt control register switched to influence the type of interrupt triggering. The The value of a sensor cable can therefore be changed generate an interrupt on the processor. Moreover is on the part of the control unit (CPU) regarding the serial transmission between meter and base none Synchronization required when setting the actuators.

Figur 1,

Blockschaltbild der Schaltungsanordnung für Meter und Base,

Figur 2,

Blockschaltbild der frankiermaschineninternen Schnittstellenschaltung,

Figur 3,

Blockschaltbild für die erfindungsgemäße Aktoren/Sensoren-Steuerung,

Figur 4,

Überwachungsschaltung mit Verbindung der Aktoren/Sensoren-Steuerung über eine Interrupt-Steuerung in der frankiermaschineninternen Schnittstellenschaltung mit der Steuereinheit,

Advantageous developments of the invention are characterized in the subclaims or are shown below together with the description of the preferred embodiment of the invention with reference to the figures. Show it:

Figure 1,

Block diagram of the circuit arrangement for meter and base,

Figure 2,

Block diagram of the franking machine internal interface circuit,

Figure 3,

Block diagram for the actuator / sensor control according to the invention,

Figure 4,

Monitoring circuit with connection of the actuator / sensor control via an interrupt control in the franking machine internal interface circuit with the control unit,

1 shows a block diagram of a Circuit arrangement for a franking machine. The Circuit arrangement can be divided into two parts, namely Assign meter and base, the base at least the motors and other actuators, sensors and the Printhead with associated control electronics contains. The meter contains the first circuit part the actual control that comes with a Input / output module 4 and in particular with one second circuit part, the invention Interface circuit internal to the franking machine connected, which is advantageously as ASIC 14 can be trained. The control includes in known way a clock / date block 8, one Character store 9, a cost center store 10, a non-volatile memory 5, program memory 11 and memory 7, which with a Microprocessor in communicative connection.

In the clock / date block 8 time data and that Date even when the franking machine is switched off generated. The input / output module 4 provides, for example via an RS 232 interface Connection to the modem 23 and possibly to the scale 22.

The latter can be part of the base. Moreover are the display controller 3 and the module 4 Keyboard 2 connected.

The input data is stored in the non-volatile memory (NVM) 5 saved so that the last setting received before the franking machine was switched off remains. The operating program is in the program memory 11 and fixed dates, for example for a Advertising slogan, saved. In the cost center memory 10 the current accounting data Depending on the cost center, non-volatile before each print saved.

The corresponding is in the character memory 9 Character set available. According to the inputs corresponding characters as pixel data in the Pixel memory 7 saved.

The microprocessor is used as a control unit 6 for the entire postage meter machine and is connected to blocks 4, 5, 7 to 11 of the first circuit part 1 via address lines A and data lines D and via address, data and control lines (A, D, S) connected to the second circuit part 14, which is designed as an ASIC. The above-mentioned blocks are addressed by the microprocessor in accordance with the memory control signals S _s generated in the decoder of the ASIC.

The function-determining ones - in FIG. 1 shown - blocks of the first circuit part partial or total to at least one physical Component are summarized and others Measures should be taken to prevent tampering difficult by unauthorized persons. The Function of these blocks and such measures are for example in German application P 43 44 476.8 explained in more detail.

The invention is illustrated in the following embodiment together with Figures 2 to 5 explained in more detail.

The circuit part 14 - shown in more detail in FIG. 2 - for the internal franking machine interface, which is designed according to the type of franking machine, has a decoder 300 for providing the memory control signals, an actuator / sensor control 400, an interrupt controller 600 and a print data controller 700. The address lines A0 to A3 and data lines D and control lines S are connected to all blocks 300, 400, 600 and 700. Address lines A13 to A19 are also present on the decoder. Decoder 300 provides memory control signals S _s for blocks 400, 600 and 700. The block 400 for the actuator / sensor control outputs a signal I _i on the output side to the block 600 for the interrupt control. The block 600 is connected on the output side to the control unit 6 via the lines for the data and control signals I _o (FIG. 1). The ASIC circuit part 14 is equipped with an input s for connection to the sensors of the base and with an output a for connection to the actuators of the base of the franking machine via a register unit 28 (FIG. 1).

Monitoring the sensors and switching or the actuators are set by the function of the - Actuator / sensor control shown in FIG. 3 400 supports. To the control unit 6 to relieve, the reading of the sensor states and the output of control bits for the Actuators by a first state machine 401 automated. The circuit contains register groups 410 to 450, comprehensive register on the one hand for communication with the control unit (CPU) 6 and on the other hand, for the state machine 401.

The entire actuator / sensor control 400 exists from a first state machine 401, two 8-bit Command register groups 420 and 421, two 8-bit (Sensor) status register groups 410 and 411, one Shift register 430 for serial transmission of the Actuator or sensor data, a mode register group 440 for setting the operating mode and an interrupt control register group 450 for influencing the interrupt generation in a logic circuit 490th

The interrupt controller 600 and the logic circuit 490 form a monitoring circuit (shown in more detail in FIG. 4) in order to send the signal I _o to the control unit 6 when the state changes on the connecting line. This allows an internal interrupt to be generated for the control unit 6. The logic circuit 490 of the actuator / sensor control 400 consists of at least one XOR logic gate, which has the first input with the Q output of a D flip-flop of the interrupt control register group 450 and the second input with the Q output of one D flip-flops 4101 of the (sensor) status register group 410 is connected. Each XOR gate of the logic circuit 490 is connected in terms of output via a signal line I _i to the associated input of the interrupt controller 600 of the postage meter internal interface circuit. The associated input is preferably a clock input of at least one D flip-flop of a register group 610, which is connected to its D input with plus potential. The Q output of the D flip-flops of register group 610 is connected to an associated input of a priority encoder 620, which interacts with a second state machine (state machine) 601. In the event of an interrupt requirement determined by the priority encoder 620, the second state machine 601 generates a request signal IRQ to the control unit 6, which responds with a response signal IACK at a given time which is dependent on the control unit. The control unit 6 can then query data D from the priority encoder 620 via the data lines, by means of which the interrupt source can be determined.

In the preferred embodiment variant, the Interrupt generation based on the four least significant Bits of the 8-bit (sensor) status register group 410. The logic circuit 490 is preferred trained as an XOR link and points accordingly the aforementioned embodiment four XOR gate on, which accordingly with four D flip-flops of register group 610 are connected. The register groups of all blocks 300, 400, 600 and 700 can - in not shown Way - within ASIC 14 its own Form block 500, which with the other blocks in Communication connection is established.

The register unit 28 is in the base with a Large number of shift registers 281 to 286 (Fig.1). The register unit 28 has - according to the way shown in Figure 3 - two the sensors 251 and 252 associated sensor shift registers 281 and 282 and two actuator shift registers 283 and 284, which with the shift register 430 of the Actuators / sensors control 400 in a loop are coupled. The ones in the base Sensors 251 and 252 provide data to the sensor shift registers 281 and 282.

The franking machine loads under the control of the first state machine 401 the value from the first command register 420 into the shift register 430th

When the data is pushed out at the same time the data of the first sensor shift register 281 the base in the shift register 430 received and the Data from the second sensor shift register 282 in the first sensor shift register 281 is shifted. After completing the pushing process, the Contents of shift register 430 (former data of sensor 251) into the first 8-bit (sensor) status register group 410 loaded. With appropriate Setting the interrupt control register group 450 this loading can lead to an interrupt.

The value from the second command register group 421 is now loaded into the shift register 430 and transmitted serially. The content of first actuator shift register 283 into the second Actuator shift register 284 pushed on. simultaneously the received bits from the sensor shift register 281 (data from sensor 252) into the second 8-bit (sensor) status register group 411 transfer.

Then the contents of the actuator shift register 283 and 284 in the corresponding Actuator registers 285, 286 loaded and the actuators switched according to the bit value. simultaneously with the copying of the actuator information Sensor shift registers 281 and 282 with the corresponding one Sensor level of sensors 251 and 252 new loaded. This is a run through the state machine 401 ended.

In a second - not in the figures shown - variant is a sensor 25 den two sensor shift registers 281 and 282 assigned, as a result of which the sensor signal can be evaluated with a higher resolution. As well could have an actuator 26 via the latches 285, 286 two actuator shift registers 283, 284 connected to realize a more precise setting.

In a third variant - not shown - can include a variety of sensors, for example Microswitch 250 for the detection of the end position during the printing process, sensor 251 for the letters - sensor 252 for strip dispenser ... Sensors are connected, which is a rough Resolution, if necessary, to reflect a pure one Have switching function.

In a fourth variant - not shown a variety of sensors a low Resolution or for the purpose of reflecting a pure one Switching function together with a sensor 253 for be connected to a higher resolution what the Evaluation of the sensor amplitude allowed.

The actuators are of the same variety connected. If a solenoid or a motor 12 only 1 bit or a motor for two directions only 2 An actuator shift register and bit can be required associated actuator register for an amplitude-time, Frequency or data preset be provided.

Likewise, using actuator shift registers and associated Actuator register threshold values for a threshold-dependent detection for a sensor be specified, which is only the threshold compares with an actual value and the bit of the comparison result to the sensor shift register transmitted. This can also be an amplitude can be evaluated, but with a large number of Sensors.

In a fifth variant - which is not specially in the Figures has been shown - becomes the actuator Sensor control (400) via at least one line connected to the register unit (28) in the base, to either query sensor signals or actuator signals for setting the actuators.

A sensor for time-critical data is the encoder 13. On the one hand, this is - in the manner shown in FIG. 1 - directly at the input e of the control unit 6 and on the other hand is connected to the input e of the second circuit part (ASIC) 14. The encoder acts on a DMA controller present in the control unit 6.
The DMA controller reads out a complete stamp image from the pixel memory (RAM) 7 and reads it into the print register (DR) of the print head 16 in columns by way of the ASIC print data controller 700. The encoder 13 acts directly on the print data controller 700 by supplying an external trigger signal for the transfer of the print data for the individual print columns to a further state machine 701.
The different systems require differently designed decoders 300 and thus different ASICs. Relative system independence can, however, be achieved using an additional decoder 900, shown in broken lines in FIG. 1, ie if the internal decoder 300 is used only partially or not to control the blocks of the first circuit part for security-relevant data by means of memory control signals S _s .

The invention is not based on the present embodiment limited. Rather, it is within the Claims a number of variants conceivable, which from the solution shown use different types of designs.

Claims (12)

1. An interface circuit integrated in a franking machine (14) comprising send and receive registers (410 - 450) for the storage of data transmitted in parallel as well as a shift register (430) for the serial/parallel or parallel/serial conversion of transmitted data,
   characterised in

   a) that an actuator/sensor control (400) equipped with the above-mentioned send and receive registers has a first status automaton (401) that is connected, on the input side, to a mode register group (440) for setting the operating mode and, on the output side, to control inputs of the shift register (430) and, via control lines, to an external register unit (28) for loading sensor signals at least from the connected sensors (25, 250, 251, ...) (LOADEXTERNAL) and shifting them into the shift register (430) controlled by the first status automaton (401) (SHIFTCLOCK);

   b) that there is connected to the shift register (430) a sensor status group (410) for at least one sensor (25, 250, 251, ...), sensor signals being callable in parallel; and

   c) that at least one sensor status register (4101) of the above-mentioned group (410) and at least one interrupt control register (450) is connected, on the input side, with a monitoring circuit (490, 600) having a combinational circuit (490) with XOR combination for monitoring the received bits of the sensor signals as to status changes in order to trigger an interrupt to the control unit (6), if necessary.
2. An interface circuit integrated in a franking machine according to Claim 1, characterised in that the actuator/sensor control (400) and the monitoring circuit (490, 600) are connected to the control unit (6); that the interrupt control register (450) and the control unit (6) are designed and programmed for pre-setting, in the interrupt control register (450), the type of change of the sensor value due to which an interrupt request is triggered and executing an interrupt accordingly so that the control unit (6) can directly branch to the respective sensor treatment routine.
3. An interface circuit integrated in a franking machine according to Claims 1 and 2, characterised in that the monitoring circuit comprises an interrupt control (600) and a combinational circuit (490), that the combinational circuit (490) with XOR combination is connected to the interrupt control (600) and delivers a signal I_i to the interrupt control (600); that the interrupt control (600) has a second status automaton (601) that is activated by a priority encoder (620) in order to supply an interrupt request signal.
4. An interface circuit integrated in a franking machine according to Claims 1 to 3, characterised in that the monitoring circuit (490, 600) is logically linked in order to monitor the low-order bits of the sensor signals as to status changes for triggering an interrupt to the control unit (6).
5. An interface circuit integrated in a franking machine according to one of the above Claims 1 to 4, characterised in that a sensor (25) is assigned to the two sensor shift registers (281 and 282) of the register unit (28) by which the sensor signal can be evaluated with a higher resolution over several bits.
6. An interface circuit integrated in a franking machine according to one of the above Claims 1 to 4, characterised in that a plurality of sensors, in particular a microswitch (250) for detecting the final position in the printing process, a sensor (251) for detecting the letter, a sensor (252) for label dispensers and/or other sensors, are connected to the register unit (28) that have a coarse resolution, e.g. one bit for reflecting a mere switching function.
7. An interface circuit integrated in a franking machine according to one of the above Claims 1 to 4, characterised in that there are connected a plurality of sensors of a low resolution, e.g. for reflecting a mere switching function, together with a sensor (253) for a higher resolution, said sensor (253) for a higher resolution allowing for an evaluation of the amplitude of the measuring value.
8. An interface circuit integrated in a franking machine according to Claim 1, characterised in that the shift register (430) is provided with two output lines to the base of the franking machine by which data can be serially transmitted between the meter of the franking machine and the external register unit (28) in the base, actuators (12, 26) being connected to the register unit (28);
   that, in the actuator/sensor control (400), command register groups (420, 421) are connected to the shift register (430) for a parallel loading of existing parallel data for actuators of command register groups (420, 421) into the shift register (430), said data then being serially read out, controlled by the first status automaton (401), for supplying the actuators in the base, wherein actuator shift registers (283, 284) are provided in the register unit (28) for a serial/parallel conversion;
   that the sensor shift registers (281 and 282) assigned to the sensors (251 and 252) are provided for parallel/serial conversion;
   and that the register unit (28) in the base is provided with a plurality of shift registers (281 to 286) that are coupled with the shift register (430) of the actuator/sensor control (400) in the franking machine to form a loop.
9. An interface circuit integrated in a franking machine according to one of the above Claims 1 to 8, characterised in that an actuator (26) is connected to the two actuator shift registers (283, 284) by the latches (285, 286) of the register unit (28) in order to realise a more exact setting.
10. An interface circuit integrated in a franking machine according to one of the above Claims 1 to 8, characterised in that there is provided a plurality of sensors of a low resolution, e.g. for reflecting a mere switching function, in particular a lifting magnet or a motor (12) for one or two directions that needs only few bits for triggering; and that there is provided one actuator with a high resolution; that the actuators can be triggered together with a actuator shift register; and that the actuator with a high resolution and an assigned actuator register are provided for a pre-setting of amplitude, time frequency or data.
11. An interface circuit integrated in a franking machine according to one of the above Claims 1 to 8, characterised in that, in the register unit (28), by means of actuator shift register and at least one assigned actuator register, there are defined threshold values for a thresholddependent detection for a sensor that only compares the threshold value with a current value and transmits the bit of the result of comparison to the sensor shift register.
12. An interface circuit integrated in a franking machine according to one of the above Claims 1 to 8, characterised in that, in the register unit (28), there are provided respective measures in a plurality of sensors so as to be able to evaluate an amplitude.

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