KR950012512B1 - Vme bus expansion board - Google Patents

Abstract

A plurality of slave boards are connected to a master board through an interface board. The interface board comprises a first bus driver for eliminating noise component contained in output data, a decoder for compressing output data of specific ports of VME bus, a voltage level detector for controlling the first bus driver according to states of receiver side port voltage, a connector for interfacing I/O data, a second bus driver for reproducing data transmitted form the connector, and a selector for selecting ports to receive data.

Description

Relay board for VME bus expansion

1 is a block diagram of a relay board for VME bus expansion in accordance with the present invention.

* Explanation of symbols for main parts of the drawings

1: Receive 1st board 10: 1st VME bus port

20: First bus drive 21: First address buffer

22: first data buffer 23: first control buffer

30: voltage sensing unit 40: first connector

50: second connector 60: third connector

61: 4th connector 70: 2nd bus drive

71: second address buffer 72: second data buffer

73: second control buffer 80: selection circuit

90: second VME bus port 100: decoder

The present invention relates to a data transmission system having a master and a slave, and in particular, a VME bus extension that efficiently relays data transmission by interconnecting slaves mounted on a backplane of a rack for expansion of the VME bus. It is about a relay board.

In general, the backplane of the VME bus is equipped with a plurality of master slots and slave slots, and is provided with a transmit board and a receive board connecting the transmission of data.

This limits the number of slots inserted into a single rack backplane to a maximum of 10 to 21 slots, which limits the transmission of large amounts of data. Therefore, if a large-capacity system is to be provided, a number of racks must be provided, thereby increasing the manufacturing cost due to the provision of an expensive master board.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object thereof is to provide a relay board capable of performing a large-capacity data transmission by maximizing the control capability of a master board inserted into a certain rack.

The present invention for achieving the above object in the VME bus having a master board and a slave board inserted into the backplane of the rack, to remove the noise component of the data output for transmission from a certain port of the VME bus, A first bus drive means for compensating for loss of a signal, a decoder means for compressing a signal output for transmission from a predetermined port of the VME bus to a predetermined state, and transmitting a data by detecting a state of a constant port voltage of a receiving side A voltage sensing means for controlling the first bus drive means, connecting means for connecting transmission and reception of the transmitted data, and compensating for and reproducing received data applied from the connecting means to prevent data lost to the first bus drive means. 2 bus drive means and selection means for selecting a receiving port of the received data. Providing a relay board for VME bus extension, characterized in that is compared.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a block diagram illustrating a relay board for extending a VME bus according to the present invention.

As can be seen in the figure, the relay board of the present invention is inserted and mounted at a predetermined position on the backplane of the rack, and includes a first bus drive 20, a voltage sensing unit 30, a first connector 40, and a second connector 50. , The third connector 60, the second bus drive 70, the selection circuit unit 80, and the decoder 100. The first bus drive 20 includes a first address buffer 21, a first data buffer 22, and a first control buffer 23 and compensates for the loss of the transmission signal applied from the first VME bus port 10. And remove the mixed noise component to form a complete transmission signal. The voltage detecting unit 30 detects the relay state of the receiving VME bus board, that is, whether the power is abnormal and detects a weak state of the power to prevent the loss of data and mixing of the transmitted data. The control operation at 20 is interrupted to interrupt data transmission. The first connector 40 and the second connector 50 are connected in parallel, and are connected to the transmission data applied from the first bus drive 20. The first connector is connected to the third connector 60 of the receiving first board 1 by a 50-pin cable, and the second connector 50 is connected to the fourth connector 60 of the receiving second board by a 50-pin cable. . The decoder 100 compresses the data signal output from the first VME bus port 10 to 96 pins into a 50 pin data signal and transmits the data signal to the first connector 40. The second bus drive 70 compensates the weak signal by reproducing the data signal applied through the second connector 50, removes noise components, and transmits the signal to the second VME bus port 90. The selection circuit unit 80 in each of the receiving boards exists to select and receive transmission data output from the first VME bus port 10 for each board, and outputs a signal for selecting the receiving board.

Referring to the operation of the present invention configured to have such a function as follows.

When the data to be transmitted from the predetermined VME bus port 10 to the predetermined VME bus port 90 is output according to the control signal of the master board with the master board, slave board and relay board mounted on the backplane of the rack, the decoder 100 compresses data output from the first VME bus port 10 to 96 pins into 50 pins, and includes a first address buffer 21 and a first data buffer 22 provided in the first bus drive 20. The first control buffer 23 compensates the address signal for the transmission data applied from the first VME bus port 10 and the loss of the data signal and the control signal to remove mixed noise components during transmission to form a complete signal. After the transmission to the first connector (7). At this time, the voltage detector 30 continuously detects the voltage state of the VME bus port to receive and determines whether data is transmitted. If the voltage state of the VME bus port on the receiving side is good, the selection circuit unit 80 selects the VME bus port to be received according to the signal applied from the transmission board, and the address buffer 72 side of the second bus drive 70 is selected. Is authorized.

In this case, if the selected transmission port is the second VME bus port 90, the second bus drive 70 sets the selected second VME bus port 90, and then compensates for the loss of the data signal applied from the second connector 50. After removing the noise component, the noise component is reproduced as an original data signal and transmitted to the selected second VME bus port 90.

As described above, the present invention combines a plurality of slave boards to a single master board through a relay board to expand a large data transmission system, and minimizes the use of expensive master boards, thereby reducing production costs.

Claims (2)

A VME bus having a master board and a slave board inserted into a backplane of a rack, the VME bus comprising: a first bus that removes noise components of data output for transmission from a fixed port of the VME bus and compensates for signal loss A drive means, a decoder means for compressing a signal output for transmission from a predetermined port of the VME bus into a predetermined state, and a first port for detecting a constant port voltage state of a receiving side to prevent data lost in data transmission. A voltage sensing means for controlling one bus drive means, connecting means for connecting transmission and reception of the transmitted data, second bus drive means for compensating and reproducing received data applied from the connection means, and the received data. A VME bus extension comprising selecting means for selecting a receiving port of the Relay board for. 2. The relay board of claim 1, wherein the first bus drive means and the second bus drive means comprise predetermined address buffer means, data buffer means and control buffer means.