KR100337157B1 - A optical communication sharing system for fieldbus - Google Patents

Abstract

The present invention relates to an optical communication distribution system for a fieldbus, which transmits data to an optical cable through a communication unit in one PCS so that it is converted into an electrical signal at a link transmitter / receiver of the first optical communication distributor and sent to a plurality of distribution controllers. and,

PCS data entering the distribution control unit, data coming from the second optical communication distributor, and data coming from the other slave station are all transmitted to the signal validity check unit so that logical data of the delayed data from one delay to eight times of encoding data is normal. To judge,

Send the result of logic combining the data verified with the logical product of the original data and the result data and the data verifying whether the optical communication splitter is first connected to the PCS to send to the link transceiver and the slave transceiver. and,

The link transmitting and receiving unit transmits data to the PCS and the next optical communication distributor through the optical cable so that data can be transmitted by the same operation as the first optical communication distributor. It can be used even when the optical communication splitter is far away, and it is possible to construct various types of fieldbus network systems and to reduce installation costs.

Description

Optical communication sharing system for fieldbus {A optical communication sharing system for fieldbus}

The present invention relates to an optical communication distribution system for a fieldbus, and in particular, when implementing an optical communication network in a large capacity plant and industrial controller, eight slave transceivers are provided in each distribution device while implementing a link transceiver and a distribution control part in each distribution device. The present invention relates to an optical communication distribution system for a fieldbus, in which a plurality of distribution devices can be installed at a long distance while minimizing electrical noise during transmission by effectively distributing data.

In general, it is well known that large-scale plant controllers or industrial controllers must effectively distribute and transmit data when forming an optical communication network for a fieldbus having a STAR topology to share data with multiple slave stations.

Conventionally, an optical communication distribution system for a fieldbus has been configured to share the same data between multiple slave stations and master stations.

That is, as shown in FIG. 1, the first communication control unit is connected to each of the input / output subsystems 1 and 11 of the field device through the optical cables 3, 3a ... 3n and 13, 13a ... 13n. (4) (14) and the second communication control unit (4a) (14a) and the n-th communication control unit (4n, 14n) is connected to convert the optical signal into an electrical signal backplane (5) ( 15) or convert the electrical signal into an optical signal to be transmitted to the subsystem (1) (11),

A bus amplification circuit (6) (16) is coupled to the backplane (5) and (15) including an address bus, a data bus, and a control bus which transmits or receives an address signal, a data signal, and a control signal. After performing the amplification in consideration of the loss, it was possible to transmit to each other distribution device (2) (12).

Therefore, in the case where data is to be transferred from the input / output subsystem 1 connected to the distribution device 2 to the subsystem 11 of the other distribution device 12, the first communication controller 4 connected through the optical cable 3 is connected. By converting the optical signal into an electrical signal is transmitted to the backplane (5).

In addition, the backplane 5 including an address bus, a data bus, and a control bus for transmitting and receiving an address signal, a data signal, and a control signal performs amplification in consideration of loss of signals transmitted and received by the combined bus amplifier circuit 6. The signal is amplified by the bus amplification circuit 16 of the other distribution device 12 to be transmitted and transmitted to the backplane 15 and transmitted to the first communication controller 4 of the distribution device 12 to receive the data. After converting a conventional signal into an optical signal, data is transmitted to the subsystem 11 connected through the optical cable 13.

However, the above-described conventional fieldbus optical communication distribution system uses the backplanes 5 and 15 and the bus amplification circuits 6 and 16, and thus cannot be used when several distribution devices are far apart. In addition, the weakness of electromagnetic disturbances such as electromagnetic interference caused a problem in the performance of the normal distribution device.

Accordingly, when the optical communication network is implemented in a large-capacity plant or industrial controller, the present invention implements eight slave transceivers in each distribution unit while implementing link transmission / reception units and distribution control units in each distribution unit, effectively distributing data and transmitting electricity. It is an object of the present invention to provide an optical communication distribution system for a fieldbus that can be installed at a long distance while minimizing noise.

In order to achieve the above object, the present invention includes a communication unit in a process control station (PCS) to transmit and receive data to and from various slave stations using an optical communication distributor distributed in each industrial site,

Transmit data to be sent through the communication unit of the active PCS through the optical cable,

Data transmitted through the optical cable reaches the link transmitting and receiving part of the optical communication distributor, which is the first of the optical communication distributors, so that the optical signal is converted into an electrical signal and sent to the distribution controller.

The data entered into the distribution controller and the data from the other slave stations are all sent to the signal validity checker.

The input data of the signal validity checker is to have data delayed from one delay to eight times of Manchester encoded data pass through the NAND gate, so if the result is '0', it is abnormal, and if it is '1', it is regarded as normal data.

Allow the original data and the resulting data to pass the AND gate to produce validated data,

The result of logic combining the data of the validity check and the data confirming whether the optical communication splitter is first connected to the PCS is transmitted to the link transceiver and the slave transceiver to be transmitted.

At this time, the link transmitting / receiving unit transmits data to the PCS and the next optical communication distributor through the optical cable.

In the second to nth optical splitters, the optical splitters are determined by determining whether or not they are to be transferred to the next optical splitter through a slave transceiver or link transmitter / receiver connected thereto by the same action as the first optical splitter. When used as a link, the link of the distribution period is used as an optical cable, which is resistant to electrical noise and can be used even when the splitter is far away, thereby not only constructing various types of fieldbus network systems but also reducing installation costs.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing the structure of a conventional optical communication distribution system for a fieldbus.

Figure 2 is a block diagram showing the overall configuration of the present invention.

Figure 3 is a block diagram showing the configuration of the distribution control unit of the present invention.

Figure 4 is a block diagram showing the configuration of the signal validity inspection unit of the present invention.

Explanation of symbols on the main parts of the drawings

21, 31: optical communication distributor 24, 34: distribution control unit

27, 37: Function selector 28, 28a, 38, 38a: Link transmitter and receiver

29, 39, 49: optical cable 42, 47: communication unit

51 to 51h, 53 and 54: signal validity test unit

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 shows the overall configuration of the present invention,

First slave transceivers 23, 33 and second of the optical communication distributors 21, 31 via cables 22, 32 to the first and second input / output subsystems 20, 30 of the field device. Connect the slave transceiver 23a and 33a and the eighth slave transceiver 23h and 33h to transmit and receive data.

Power is supplied from the power supply units 25 and 35 to the distribution control units 24 and 34 connected to the first to eighth slave transceiver units 23 to 23h and 33 to 33h by cables 22 and 32. Receiving and to adjust the cycle of the operation by the clock generated by the clock generator 26, 36,

In the distribution control unit 24, 34, which receives the position data signal according to the position where the optical communication distributor 21, 31 is connected from the function selection unit 27, 37, the link transmitter / receiver 28, 38 is connected. The optical signal received through the optical cable 29 between the link transmitter and receiver 38 and 28 of the other optical communication distributors 31 and 21 into an electrical signal or by converting the electrical signal into an optical signal. Send it,

Communication units of the first and second PCSs (Process Control Stations) 41 and 46 are connected to the link transmitter / receivers 28a and 38a of the optical communication distributors 21 and 31, respectively, through the optical cables 39 and 49, respectively. 42) (47) to transmit and receive data,

The PCS 41 and 46 have main controllers 43 and 48, arithmetic units 44 and 49, and memory backup units 45 and 50, respectively, and are slaved through the communication units 42 and 47. It is to perform communication for controlling the operation with the station.

Figure 3 shows the internal configuration of the distribution control unit of the present invention,

The data signals transmitted to the distribution controllers 24 and 34 through the link transmitter / receivers 28, 38, 28a and 38a are passed through the first to eighth signal validity checking units 51 to 51h. Is applied to the oragate 52 so as to be OR

The downlink signal transmitted to the distribution control unit 24, 34 through the link transmission / reception unit 28, 38, 28a, 38a is passed through the downlink signal validity checking unit 54,

The data signals transmitted from the slave station to the distribution controllers 24 and 34 through the first to eighth slave transceivers 23 to 23h and 33 to 33h are transmitted to the first to eighth signal validity checkers 51. Is applied to the oragate 52 via-(51h),

The uplink signals transmitted to the distribution controllers 24 and 34 through the first to eighth slave transceivers 23 to 23h and 33 to 33h are passed through the uplink signal validity checker 53. To be applied to one side of (57),

The output of the oragate 52 is input to one side of the AND gate 55 and the oragate 59,

The position data signal according to the position where the optical communication splitters 21 and 31 are connected from the function selector 27 and 37 is applied to one side of the three end gates 55 and 56 and 57,

The output of the AND gate 56 to which the output of the downlink signal validity checking unit 54 is applied to the other side, the output of the AND gate 55, and the output of the uplink signal validity checking unit 53 are input to the oragate 58. To output the link to the link transmitter and receiver.

The output of the AND gate 57 and the output of the downlink signal validity checking unit 54 are applied to the oragate 59, and the output thereof is the first to eighth slave transceivers 23 to 23h (33 to 33h). To be output as

Figure 4 shows the configuration of the signal validity test unit of the present invention,

The input data signal is sequentially delayed by the delay elements 61 to 68, and is passed through the NAND gate 69 so that the result data is '0' and abnormal, and '1' to judge normal.

The input original data signal and the result data of the NAND gate 69 are input to both sides of the AND gate 70 so as to be output as valid data verified by the output.

The optical bus distribution system for fieldbus of the present invention configured as described above has communication units 42 and 47 provided in the PCS 41 and 46, and various slave stations and data are provided through the optical communication distributor distributed in the industrial field. As the transmission and reception of the data, the flow of data transmission and reception is as follows.

Data to be transmitted is transmitted via the optical cable 42 through the communication unit 42 of the PCS 41 which is activated among the PCS 41 and 46.

The data transmitted through the optical cable 42 reaches the link transmission / reception unit 28 of the optical communication distributor 21, which is the first of the optical communication distributors 21 and 31, so that the optical signal is converted into an electrical signal and the distribution controller 24 Is sent).

The first through the eighth slave transceivers 23 through the cables 22 and 32 in the first and second input / output subsystems 20 and 30 which are slave stations different from the data entered into the distribution control unit 24. All data from (23h) will be tested for signal validity.

That is, the data signal transmitted to the distribution control unit 24 through the link transmission / reception unit 28 is applied to the oragate 52 via the first to eighth signal validity checking units 51 to 51h to perform a logical sum. While doing so, the downlink signal passes through the downlink signal validity checking unit 54.

The data signal transmitted from the slave station to the distribution control unit 24 through the first to eighth slave transceivers 23 to 23h is transmitted via the first to eighth signal validity checking units 51 to 51h. The uplink signal is applied to the OR gate 52 to be applied to one side of the AND gate 57 via the uplink signal validity checker 53.

The output of the oragate 52 is input to one side of the AND gate 55 and the oragate 59, and according to the position where the optical communication splitters 21 and 31 are connected from the function selection unit 27 or 37. The position data signal is applied to one side of the three AND gates 55, 56 and 57.

The output of the AND gate 56 to which the output of the downlink signal validity checking unit 54 is applied to the other side, the output of the AND gate 55, and the output of the uplink signal validity checking unit 53 are input to the oragate 58. To output the output to the link transmitter / receiver 28,

The output of the AND gate 57 and the output of the downlink signal validity checker 54 are applied to the oragate 59 so that the output is output to the first to eighth slave transceivers 23 to 23h.

In the signal validity checking unit 51 to 51h and 53 and 54, the input data signal is sequentially delayed by the delay elements 61 to 68, while passing through the NAND gate 69. If the data is '0', it is abnormal. If the data is '1', it is determined to be normal. Then, the validity of the output of the AND gate 70 into which the input original data signal and the result data of the NAND gate 69 are input to both sides is verified. Output the generated data.

The link transmitter / receiver 28 and the slave transmitter / receiver 23 show the result of logic combining the data of the above-mentioned validity check and the position data signal for checking whether the optical communication distributor 21 is first connected to the PCS 41. To 23h).

At this time, the link transmitter / receiver 28 transmits data to the PCS 21 and the next optical communication distributor 31 through the optical cables 39 and 29.

The second to nth optical splitters determine whether to transmit to the next optical splitter through the slave transceiver or link transmitter / receiver connected to the first optical splitter by the same action.

Therefore, in the fieldbus optical communication distribution system of the present invention, the data to be transmitted through the communication unit in the PCS is transmitted to the distribution controller by converting the electrical signal from the link transmitter and receiver of the first optical communication distributor to meet the optical cable,

Both the data coming into the distribution controller and the data from the other slave stations are sent to the signal validity checker to determine whether or not the normal data is a logical product of the data delayed from one delay to eight times of the encoding data.

Send the result of logic combining the data verified with the logical product of the original data and the result data and the data verifying whether the optical communication splitter is first connected to the PCS to send to the link transceiver and the slave transceiver. and,

The link transmitting and receiving unit transmits data to the PCS and the next optical communication distributor through the optical cable to perform data transmission by the same action as the first optical communication distributor. When each optical communication distributor is used as the optical communication distribution device, the link of the distribution period is connected to the optical cable. It can be used even when the splitter is far away, making it possible to construct various types of fieldbus network systems and to reduce installation costs.

Claims (4)

First and second PCSs 41 and 46 including main controllers 43 and 48, arithmetic units 44 and 49, and memory backup units 45 and 50; The link transmitter / receivers 28a and 38a of the optical communication distributor 21 (31) are connected to the communication units 42 and 47 of the first and second PCSs 41 and 46, respectively, via the optical cables 39 and 40. Connect, The link transmitter / receivers 28 and 38 include distribution controllers 24 and 34 which receive position data signals from the function selector 27 and 37 according to the position at which the optical communication distributors 21 and 31 are connected. The optical signal received through the optical cable 29 between the link transmitting and receiving units 38 and 28 of the other optical communication distributors 31 and 21 by converting the optical signal into an electrical signal or by converting the electrical signal into an optical signal. Let's do it, The first to eighth slaves connected to the distribution controllers 24 and 34, which are supplied with power from the power supply units 25 and 35, and whose operation periods are aligned by the clocks generated by the clock generators 26 and 36. Field transceiver for transmitting and receiving data to and from the transmission and reception unit 23 to 23h (33 to 33h) to the first and second input and output subsystems 20 and 30 of the field device via cables 22 and 32. Optical communication distribution system. delete 2. The distribution control unit (24) according to claim 1, wherein the distribution control unit (24) 34 transmits the data signals transmitted from the link transmitting and receiving unit and the slave station via the first to eighth signal validity checking units (51) to (51h). 52) The downlink signal is passed through the downlink signal validity checking unit 54, The uplink signal is applied to one side of the AND gate 57 via the uplink signal validity checking unit 53, The output of the oragate 52 is input to one side of the AND gate 55 and the oragate 59, The position data signal according to the position where the optical communication splitters 21 and 31 are connected from the function selector 27 and 37 is applied to one side of the three end gates 55 and 56 and 57, The output of the AND gate 56 to which the output of the downlink signal validity checking unit 54 is applied to the other side, the output of the AND gate 55, and the output of the uplink signal validity checking unit 53 are input to the oragate 58. To output the link to the link transmitter and receiver. The output of the AND gate 57 and the output of the downlink signal validity checking unit 54 are applied to the oragate 59, and the output thereof is the first to eighth slave transceivers 23 to 23h (33 to 33h). Optical communication distribution system for fieldbus which is output by 4. The signal validity checking unit according to claim 3, wherein the signal validity checking unit causes the input data signal to be sequentially delayed by the delay elements 61 to 68, and passes through the NAND gate 69 so that if the result data is '0', it is abnormal. 1 'is judged to be normal, And the input original data signal and the result data of the NAND gate (69) are input to both sides of the AND gate (70), so that the output is verified as validity by the output thereof.