SU596939A1 - Arrangement for interfacing terminals with data transmission apparatus - Google Patents

Description

(54) DEVICE FOR MATCHING TERMINALS WITH DATA TRANSMISSION EQUIPMENT

The invention relates to digital computing and can be used for input - output information in digital computing systems.

A device for interfacing is known comprising a line state analysis unit, a priority unit, a request unit, a signaling unit and a telegraph unit 1.

However, the known device does not provide two-way information exchange with a computer in the interactive mode of the terminal.

The closest in essence technical solution is a device for interface of terminals with data transmission equipment, containing a priority block of received information, an output group of which is respectively connected to a group of control outputs of a device, a priority block of transmitted information, a group of inputs of which is respectively connected to a control group device inputs, a memory unit and a transmitting register, the first inputs of which are connected to the first information input of the device, the transmission control unit , the first output of which is connected to the second input of the transmitting register, the second output of the transmission control unit and the output of the transmitting register are connected respectively to the first control and

the information outputs of the device, the first control and the second information inputs of the device are connected respectively to the input of the reception control unit and the first input of the receiving register, the first output and the second input of which are connected to the second information output of the device and the first output of the reception control unit 2.

However, this known device does not provide for the exchange of terminals with a computer with variable length messages.

The aim of the invention is to enable the terminals to exchange variable-length messages.

To do this, a terminal address decoding unit, an operation attribute decoding unit, a service attribute decoding unit, a terminal address encoding unit and a terminal status byte generating unit are added to the device, the second outputs of the reception control unit and the receiving register are connected respectively to the service decoding unit inputs, the output of which is connected to the first inputs of the decoding unit of the terminal address and the decoding unit of the operation tag, the second inputs of which are connected to the first you the receiving register, the output of the terminal address decoding unit is connected to the priority block input of the received information and the second memory block input, the third and fourth inputs of which are connected respectively to the output of the operation indicator decoding block and the first output of the terminal state byte shaping block, This information is connected to the first input, ohm of the terminal state byte shaping unit, the second input of which is connected to the third input of the transmitting register and the output of the unit to the terminal address, the output of the memory unit is connected to the third input of the terminal state byte generation unit, the fourth input of which is connected to the input of the transmission control block and the first output of the priority block of transmitted information, the first and second inputs of the terminal address coding block the priority of the transmitted information and the terminal state byte shaping unit. The drawing shows a structural electrical circuit of the device. The device for interfacing terminals with data transmission equipment comprises a memory block 1, a priority information block 2 of the received information, a transmission information priority block 3, an operation feature decoding block 4, a terminal address decoding block 5, a terminal address encoding block 6, a decoding block service signs, block 8 of forming the state bytes of the terminals, block 9 of receiving control, receiving register 10, transmitting register I, and block 12 of controlling transmission. Connection of the device for interface to other devices of the numeral system is carried out using control input groups - outputs 13 to terminals and groups of information inputs - outputs 14 to data transmission equipment operating in duplex mode. The device works as follows. To establish a connection with a computer, the terminal operator presses twice on the symbol key, which cannot be combined in ordinary texts (for example, “ъ”, “Ь, etc.). When you press a key through the inputs 13, the code symbol is fed to the input of block 8 and register 11, and the request is sent to the corresponding input of block 3 of the priority of the transmitted information. In the absence of requests from terminals with a higher priority, block 3 outputs to block 8 an analysis resolution signal. If block 8 distinguishes the symbol “ъ, and in block I at the terminal address of the sign“ ъ. no, a sign of a possible status byte is issued in block 1 and fixed. The transmission of the symbol "ъ rfa register 11" and to the communication channel is temporarily blocked. Upon receipt of the following signal from this terminal, block 8 conducts its analysis on “ъ taking into account the information 1.ii read from block 1 at the address of the terminal. At the same time, the following options are possible: - the second character “ъ” arrived from the terminal (such a sign was stored in the block). Block 8 forms a byte "Attention and issues a signal to the terminal address encoding block b. Block 6 generates the address of the terminal with the indication of the status byte output and outputs it to the transmitting register 11 and then accompanied by synchronization signals (13 by the transmission control unit 12 to the data transfer equipment to the outputs 14. The next status byte is transmitted from block 8 to the register 11, the outputs 14 to the data transmission equipment; -the terminal received a symbol other than the symbol "ъ. Referring to block 1 showed that the first symbol" ъ is stored in the block. In this case, the signal from block 8 forms the address byte with the sign data. The next byte comes from block I through block 8 to register 11 and then to outputs 14. The next byte transmitted by block 8 is transmitted in the same way to data transfer equipment. Only by register 11 does this byte come from inputs 13 the terminal has the symbol "ъ, and in block 1 there is no sign of the first symbol" ъ. In this case, the signal from the output of block 3, block 6 generates an address byte with the data attribute, the address byte is transmitted to the data transmission equipment from block a b, and a byte (character) of data from inputs 13 of the interface with the corresponding term and cash. In all cases, except for the arrival of the symbol "ъ, in block 1, the sign of the performed operation" read or "write should be stored. The command determining the nature of the operation performed by the terminal comes from the receiving communication channel and is recognized in the information flow. For this, all the information available from the inputs 14 to the receiving register 10 is analyzed by the block 7 for decoding the service features for the presence of an address feature. If there is an indication of the address, block 7 signals in block 5 of the decoding of the address of the terminal and in block 4 of the decoding of the indication of the operation, if the instruction byte is in the address byte. The command code ("read or" write), arriving in the next byte, is recorded in block 1, and the address goes to the priority block 2 of the received information and is used to switch the next byte from the output register-. 10 by exits 13. Referring to the transfer of bytes to block 1 -c checking the correctness of the operation performed eliminates erroneous situations: -the presence of information on inputs 13 and the indication of the command "write in block 1, -the presence of information for a particular terminal on register 10 and the feature of the command "Read in block 1. In the event of such an alarm situation, block 8 generates a byte of the state Opshbka in the data and accompanied by the address of the terminal, during which the error is detected, sends to register 11 and exits 14. The corresponding byte No data is sent to the terminal or is not received from the terminal in the computing machine. When using the proposed device, both formalized and non-formalized information of multiple terminals is exchanged with a computer through a single duplex communication channel used in group mode. Both batch and interactive terminal modes are possible in the absence of restrictions on the length of transmitted messages.

Claims (2)

1. USSR author's certificate No. 359769 of cells. -H 04L 11/15, 1969. 2.Ogann R.V. The interface with the communication lines B of the computational 5 of the complex, “Problems of Radioelectronics, Seri EVT, Vol. 8, 1971, p. 109-113.