DE29606810U1 - Data switch for EDP devices - Google Patents

Description

Utility model registration Bernd.gßlinger page

Description ·&iacgr;

The invention relates to a data switch for computer devices, as it is used in particular as a printer switch.

Such switches are generally used to connect several computers to one and the same peripheral device. If a switch has, for example, two inputs El and E2 and one output A, two data paths El to A and E2 to A can be set using a switch S. If a computer is connected to El and E2 and a printer to A, the switch S can be used to select the computer 1 or 2 that is allowed to access the printer. In the same way, other peripheral devices, such as modems, can also be switched using such switches. Versions of data switches are also known in which the switch S is implemented in electronic form. In this case, an operating mode is usually provided in which the peripheral device is assigned to the computer that sends data first among all the computers connected to the E inputs.

In addition to wired data transmission to peripheral devices, wireless data transmission is becoming increasingly important. Point-to-point connections via infrared data interfaces in accordance with the IrDA® standard are currently common. A growing number of portable computers are already equipped with such interfaces. If two devices, such as two computers or a computer and a peripheral device, have such an optical interface, no cable connection is required between the devices involved to exchange data. It is sufficient to arrange the devices a short distance from one another.

A particularly advantageous application of wireless data communication arises when a portable computer and a printer have such an interface. In this case, it is sufficient to place the portable computer near the printer for printing. After the print job has been processed, the mobile computer is simply removed again. This completely eliminates the need to connect and disconnect cables.

Utility model registration Bernd ₍

A disadvantage of using wireless data communication is that the peripheral device in question must also have a wireless data interface. Most of the peripheral devices currently on the market, especially the printers on the market, do not have such an interface. The same applies to older devices already present in a computer system. In this case, if a mobile computer with an infrared printer interface is to be used to print wirelessly to a conventional, i.e. wired printer, the only option is to use an intermediate computer equipped with an infrared interface, which receives the print job from the portable computer and forwards it to the wired printer. This process is cumbersome and takes up capacity on the intermediate computer.

The invention is therefore based on the object of creating a device that enables direct wireless data communication with devices that have no or an incompatible wireless data interface as standard.

This object is achieved by a device according to claim 1 or 2. Advantageous embodiments emerge from the subclaims.

In the following, an embodiment of the invention is described in detail with reference to the single figure 1. The figure shows a block diagram of a data switch U designed as a printer switch according to claim 1 or 2. It has a wired data connection El, which has 8 parallel data lines plus handshake lines. In addition, there is a connection E2 for wireless data communication. The electrical characteristics of connection A are identical to those of connection El. Two data paths El-A or E2-A can be set via the electronic switch 5. A bidirectional data flow can be provided.

The wireless data connection E2<

Utility model registration Bernd, ^!.Slinger

&bull;is in*13eifepieT as optical

Interface designed according to the IrDA standard. A commercially available, IrDA-compatible transceiver is used as the connection element. Since the IrDA standard is based on serial data transmission, a serial/parallel converter 3 is required, which converts the serial data received from the infrared port E2 into the parallel data format of port A. It is also necessary to convert the handshaking information from the printer when receiving data into serial control characters for the computer R2. In the example, this is done by sending the ASCII control character XOFF to the computer R2 via E2 when the printer D is not ready to receive, whereupon the computer interrupts the data output. When the printer is ready to receive again, this is signaled to the computer R2 via the ASCII control character XON. The conversion of the printer handshaking into the XON/XOFF protocol is carried out by the protocol converter 4.

The microprocessor 2 continuously monitors via the lines L1 and L2 whether data traffic is taking place via one of the E connections. For the duration of the data traffic plus a timeout period, the other E connection is blocked. To prevent erroneous printing, a blocked S connection appears to the assigned computer as if the printer is not ready. After the end of the data traffic and the expiration of a timeout period, connection A is connected to the E input that first registers data traffic. To do this, the electronic switch 5 is set to the appropriate position via the selection line W.

In the design of the changeover switch according to claim 2, also shown in Fig. 1, there is also an operating switch T, an electronic switch 6 and another connection B. When the switch T is operated, the microprocessor 2 connects the connection E2 to the connection B via the electronic switch 6. At the same time, it sets the switch 5 so that A is permanently connected to El. This state is maintained until another operating mode is selected via the operating switch T.

Utility model registration Bernd^ JSßlLnger Page 4

In a further advantageous embodiment, there is a buffer memory 7 for each of the connections E1 and E2. In this way, the switch according to the invention can receive data via a connection E, even if the printer D is connected to the other connection at that time. If the buffer memory 7 is present, the connections E do not need to be blocked if the printer is not currently available.

Using the switch U outlined in Figure 1, you can print from the computer Rl to the printer D via a cable as usual. No changes to the software of the computer Rl are required, as the switch U appears to be completely transparent with regard to the data path El-A. At the same time, the printer D can also be controlled via the wireless data connection E2. This does not require any changes to existing settings or the re-plugging of cables.

A modification occurs when the connection E2 is permanently connected to the connection A via the elements 3, 4 and possibly 7, whereby the connection El is omitted. In this case, a simply constructed protocol converter is created that converts the protocol of the wireless data interface E2 to the protocol of the wired data interface A and vice versa.

Note: ¹¹ IrDA" is a registered trademark of the Infrared Data Association, USA.

Claims (5)

Utility model registration Bfpnd,JS ·· ·* &idiagr;&Idigr; i · &iacgr; * ·»· Bernd,»Eßlinger Page Protection claims ..·»·· 1. Data switch for EDP devices, in particular printer switches, with &eegr; connections E^ to E _n and at least one connection A, for selectively connecting a connection from the set E^ to E _n to the connection A, characterized in that at least one connection E^ of the connections E^ to E _n is designed as a wireless data interface. 2. Data switch for EDP devices, in particular printer switches, with n connections E^ to E _n and at least one connection A, for selectively connecting a connection from the set E^ to E _n to the connection A, wherein at least one connection E(j of the connections E^ to E _n is designed as a wireless data interface, characterized in that the connection E^ can be connected to a connection B, whereby the set of connections that can be connected to A is reduced to E^ to E _n without E<j for the duration of this connection. 3. Data switch according to claim 1 or 2, characterized in that the terminal E<j can be connected to at least one of the other terminals E ₁ to E _n . 4. Data switch according to one of the preceding claims, characterized in that it has a protocol converter which converts the data format and data protocol of the wireless data interface E^ into the data format and data protocol of the connection (A, B or E^ to E _n ) connected to the connection E^ and vice versa. 5. Data switch according to one of the preceding claims, characterized in that the connection E^ is designed as an infrared data interface.