DE3716141A1 - Charge indicator for ISDN switching systems - Google Patents

Abstract

In order to produce a charge indicator for ISDN switching systems, it is proposed that a processor unit comprising an I/O port, a RAM, an EPROM and a microprocessor be connected to the Y interface of an ISDN terminal, its power being supplied by means of a DC/DC converter which is connected to the ISDN feed, input keys and a key-operated switch being connected upstream of the I/O port, disconnection from the Y interface is also provided on the I/O port, the data retrieved from the I/O port (via the Y interface and keys or switches) are read via a data bus into the RAM which contains the data for the summation counter, the individual counter and the charge factor, furthermore into the EPROM which contains the charge indicator software, and into the microprocessor, an address bus furthermore connecting the RAM, EPROM and mu P and the mu P being connected to an LCD on which the data calculated by the mu P are shown. <IMAGE>

Description

The invention relates to a fee indicator for ISDN switching systems

With the introduction of the ISDN it becomes a new one Generation of telephone sets. In addition to complex multifunctional terminals with features that go far beyond speaking out are also inexpensive Telephones provided only the basic fulfill functions in ISDN and neither via Display still have a key switch

Proceeding from this, the object of the invention based on participants with such basic models nevertheless the opportunity to offer the accruing Capture fees.

To achieve this object, the invention proposes that a processor unit, consisting of an I / O port, a RAM, an EPROM and a microprecessor, be connected to the Y interface of an ISDN terminal and its power supply to the ISDN by means of a The DC / DC converter is switched on, the I / O port input keys and a key switch are connected upstream, the disconnection to the Y interface is also provided on the I / O port, which is queried by the I / O port Data (via Y interface and keys or switches) via a data bus into the RAM, which contains the data about the totalizer, the single counter and the charge factor, furthermore into the EPROM, which contains the software of the charge indicator, and into the microprocessor are read in, an address bus also connecting RAM, EPROM and µP and the µP being connected to an LCD display on which the data calculated by the µP are displayed.

Advantageous further developments are in the Sub-claims referred.

The solution is essentially that a separate charge indicator for ISDN was created has been.  

This is operated as an additional device at the Y interface of the ISDN telephone set, which is carried out on a telecommunications connection unit (TAE). There the fee indicator is either hard-wired or plugged into a TAE.

The fee indicator essentially has the following features:
Microprocessor control,
Display of fee units,
Single and total counters,
Display of fees in monetary amounts,
easy programming of the fee factor,
easy retrieval of the memory contents,
Display of charges during a call,
permanent information when switched off completely over several days.

At the request of the participant, what in particular advantageous for hotel businesses or the like the charge indicator can also be multi functional terminals are operated.  

The specific design of the fee indicator is realized in a housing, this device as a table device with or without a special stand can be used. It is also for surface mounting suitable for installation. The case is made up of reason plate and cover cap. On the base plate attached to the circuit board that holds the electronic Circuit as well as the controls, the display and contains the terminals. For wall mounting we mounted the base plate with two screws.

The cover cap has openings for the display, for two buttons and a key switch. The connecting cord is on the side, for example passed through the base plate at the bottom right. they has an anti-kink sleeve on the side of the device with strain relief. The controls are as follows dimensions marked:

C / P key (momentary) delete / program, G button (latching) toggle, charges unit / amount of money

Key switch
Position 1 (latching) Deleting the total memory, position 2 (latching) Normal position, position 3 (latching) Programming the charge factor.

On the preferably 16-digit single-line LCD display will be the 7-digit sum on the left all accruing and the right 5-digit the current Charge units per call are displayed. By switching over, the Amount of money (fee units × fee factor are displayed.

The function of the device is under simultaneous Explained with reference to the accompanying drawings. Show it

Fig . 1 and 2 the device-like embodiment of the charge indicator in front view and side view;

Fig . 3 an overview plan for the connection of the fee indicator in ISDN;

Fig . 4 shows a variant of an interface;

Fig . 5 Block diagram of the charge indicator.

The charges will be in the analog telephone network units by adding 16 kHz charges impulses determined during a conversation at certain intervals from the operator be transferred.  

Because of the digital, protocol-controlled Signaling in ISDN are the fees here were transmitted during a conversation, but not at the same time, but in times of low utilization of the control. To The current status can then be read at the end of the call will.

The charge information is made up of layer 2 and Layer 3 messages formed by the DIV. The Identify signal ANF and END (layer 2 message) records the beginning and end of the fee-based Time.

GEBA, GEBI and GEBE signals (Layer 3 messages) give information parameters of the fee units at.

The transaction indicator (TRID) is part of it the Layer 3 message.

For example, a fee transfer looks like follows from:

ANF; Reset the total memory at the beginning;  ANF; GEBI 10 receipt of 10 fee units; ANF; GEBI 20 receipt of 20 fee units; ANF; GEBI; TRID reception of the current Fee units according to End of call.

With the GEBE and GEBA signals, fees can also be charged units are transferred.

The charge indicator has the following functions units:

Microprocessor control,
2k EPROM,
2k RAM with buffering,
I / O port,
DC / DC converter,
LCD module,
Power failure detection,
galvanic isolation by optocoupler.

Since the fee indicator from the 40 V additional ver supply is only allowed to withdraw approx. 350 mW Circuit concept in CMOS or HCMOS technology realized.  

The CPU system, consisting of a Z80-µP, a 2k EPROM and a 2k RAM is made with one clock frequency of 4 MHz operated. The clock frequency was therefore chosen so high when loading of characters in the LCD module optical inscription avoid effects.

The software for the fee indicator is in the EPROM saved. The RAM contains the data for the Total and single counter and the fee factor. Through a capacitor buffer circuit in the event of a power failure, the data over several days in Maintain RAM.

Keys and key switch positions as well as the control lines of the Y interface are queried via the I / O port.

The Y interface to the terminal in the charge indicator is galvanically isolated by optocouplers. Resistors in the emitter circuit ensure the transmission requirements. The signal levels are sufficiently high due to the low LED current of the optocouplers.

The display consists of a 16-digit dot matrix display in LCD technology. It is from µP controlled and offers characters, numbers and book letters of the ASCII character set.

To prevent loss of data in the event of a power failure is prevented by the power failure detection circuit a defined behavior of the micro processor when the network is switched on again causes.

The adaptation of the 40 V additional supply to the 5 V required for the charge pointer takes over a developed DC / DC converter.

Operation is as follows:
After the charge indicator has been properly connected to the Y interface of an ISDN terminal, it shows the following information on the display regardless of the position of the key switch: "Factor is missing."

To program the fee factor, the Key turned to position 3. On the display "Factor → C / P" appears. The fee factor is entered in 3 digits. Press the C / P key to run the digits the first digit in succession until the key is released. By pressing the The C / P key sets the second digit and the third digit when pressed again. The display shows the programmed fee factor as long as the key is in position 3 located. The key switch position is 2 the normal position. In it are the fees units during an outgoing connection shows. If the G key is pressed, appears on displaying the monetary amount of the fee units.

The total cost of the individual calls is also shown in switch position 2. When the G key is pressed, appears here too the amount of money. After the end of the call, the Counter contents are displayed for approx. 6.5 seconds each shows.  

By pressing the C / P key for the units or G for the monetary amounts, the display can be any be repeated often.

The single counter starts with a new one outgoing connection deleted.

The totalizer can only use one procedure to be deleted. To do this, the key is in position 1 turned. The blinking of the display signals readiness to delete.

Pressing the C / P key will save the memory deleted. Then the totalizer shows zeros at. The totalizer can be deleted by flipping a switch on the circuit board be prevented.

If an individual or total counter overflows, that is, for the single counter at more than 99 999 fee units and for the totalizer for more than 9 999 999 fee units, appears <in the respective field in front of the counter display and in the counter field the difference between the actual 10,000 or 10,000,000 fees.  

The overflow in the cash amount display is handled accordingly.

The invention is not based on the execution example limited, but within the scope of the open in many cases variable.

All new, in the description and / or drawing disclosed individual and combination features regarded as essential to the invention.

Claims (7)

1. Fee indicator for ISDN switching systems, characterized in that a processor unit, consisting of an I / O port, a RAM, an EPROM and a microprocessor, is connected to the Y interface of an ISDN terminal, the power supply by means of a DC / DC converter connected to the ISDN supply, the I / O port input keys and a key switch are pre-switched, the shutdown to the Y interface is also provided on the I / O port provided by the I / O Data queried by O-Port (via Y interface and keys or switches) via a data bus into the RAM, which contains the data for the totalizer, the single counter and the charge factor, furthermore into the EPROM, which contains the software of the charge indicator, and are read into the microprocessor, an address bus also connecting RAM, EPROM and µP and the µP being connected to an LCD display on which the data calculated by the µP are displayed. 2. Fee indicator according to claim 1, characterized in that between Y interfaces and I / O port, a galvanic isolation, in particular by means of an opto coupler. is provided. 3. Fee indicator according to claim 1 or 2, characterized in that a to the RAM Capacitor buffer circuit as a power failure data backup is switched on. 4. Fee indicator according to claim 1 to 3, characterized characterized that the display is off there is a 16-digit dot matrix display, what characters, numbers and letters of the ASCII character set includes. 5. Fee indicator according to claim 1 to 4, characterized characterized in that the display shows a Contrast slider. 6. Fee indicator according to claim 1 to 5, daddurch characterized in that as input keys Delete and programming key in key switch  technology, a shift key charge unit / Amount of money, especially in rest stops technology, as well as a key switch with 3 stop positions for deleting the total memory, normal position and programming of the fee factor are provided. 7. Fee indicator according to claim 1 to 6, characterized characterized that the entire unit in a be from base plate and top cap standing housing on a circuit board is arranged, which is attached to the base plate is, with the top cap openings for the display, the contrast control, the Has keys and the key switch and the terminals for the external Wiring also on the circuit board are arranged.