Device for conflict detection in local area network
(57) Abstract:The invention relates to computer technology and can be used in local area networks with multiple access with carrier detection and collision detection. The purpose of the invention is to increase the reliability of detection of conflicts in the local area network. The goal is achieved by introducing the differentiator 3, a full-wave rectifier 4, odnovorov 5, 6, and 7, item, OR 8, the delay element 9, the reversible counter 10, figure 11, comparison, the one-shot 12 to re-start and D-flip-flop 13. This allows for the addition of signals in the channel from two or more subscribers to detect conflicts in the network by the presence of fluctuations of the level of the total signal during the private information of the pulses, thereby increasing the accuracy of collision detection. 2 Il. The invention relates to computer technology and can be used in local area networks with multiple access with carrier detection and collision detection.The aim of the invention is to increase the reliability of detection of conflicts in the local area network.In Fig.1 predstavleniyami 1 and ed 2 transformers, the differentiator 3, (full-wave) rectifier 4, adenovirally 5, 6 and 7, element, OR 8, the delay element 9, the reversible counter 10, figure 11 comparison, the one-shot 12 (re-run) and D-flip-flop 13. Direct and inverted inputs of the transmitting transformer 1 is connected to the bus 14 "Encoder", direct and inverted outputs of the transmitting transformer 1 is connected to the bus 15 "Mono" and to direct and inverse inputs of the receiving transformer 2, the output of which is connected to the bus 16 Decoder. The device has a bus 17 "Threshold" code, the tire 18 "Initial code", the tire 19 "Conflict", entry 20 Reset, bus 21 logical "1".The device operates as follows.Before you begin it is necessary to apply a signal on bus 20 "Reset" to set in the initial state of the trigger 13, wherein the signal on the bus 19 "Conflict" is missing. Then on the bus 14 "Encoder" is code for the Manchester-2 in the form of two unipolar pulse sequences to direct and inverted inputs of the transmitting transformer 1, where it is converted into a bipolar pulse sequence and enters into the tire 15 "Mono". From tires 15 "Mono" bipolar code Manchester-2 arrives at the receiving transformer 2, the output of which the pulses of this code the pulses, coming from the tires 15 "Mono input" (see Fig.2). The differentiated pulses from the differentiator 3 is fed to the input of a full-wave rectifier 4, which transmits the pulses of positive polarity and translates into the positive pulses of negative polarity. The rectified pulses from the rectifier 4 is fed to the input of one-shot 5, from which all differentiated and rectified pulse generates a pulse of the same duration. These pulses arrive at the summing input of the reversible counter 10. Simultaneously, private information pulses from the direct input of the transmitting transformer 1 arrive at the direct input of one-shot 6 and an inverse input of one-shot 7. Adenovirally 6 and 7 form the pulses respectively on front and rear fronts of private information pulses through the OR element 8 and the delay element 9 is coming to the subtractive input of the reversible counter 10. Furthermore, the original information pulses fed to the input of the one-shot 12 with repeated startup and continually run it, maintaining the signal at the direct output and supporting the absence of a signal at its inverted output. The signal from the inverted output of the on signal, i.e., when private information pulses in the network are not issued, continuously writes the initial code in the reversible counter 10 with tires 18 "Initial code". When you are issuing their own information pulses, the one-shot 12 all the time puzauskaite, the signal at its inverted output is missing and, therefore, the initial code in the reversible counter 10 is not recorded. Thus, if in the network there are no conflicts, i.e., in "Mono" 15 issued only private signals and no signals of other subscribers, the reversible counter 10 is folded and subtracts the same number of pulses, and its readings do not change, remaining equal to the initial code. In order to avoid overlapping of pulses to the counting inputs of the reversible counter 10, the signals arriving at its subtractive input, delayed by the delay element 9. Code output from the reversible counter 10 is fed to the input circuit 11 comparison to the other input of which receives the threshold code with tires 17 "Threshold" code, which is chosen large initial code in the reversible counter 10, and in the absence of collisions on the network no signal on the output of the circuit 11 comparison, the D-flip-flop 13 nothing is written and there is no signal on the bus 19 Conflito to the subtractive input of the reversible counter 10 is not changed, and increases the number of pulses at the output of the differentiator 3 due to the appearance of additional lines on a total signal resulting from the addition or subtraction of signals conflicting subscribers (see Fig. 2). These pulses, after passing through a rectifier 4 and the one-shot 5 arrive at the summing input of the reversible counter 10. Due to this, in the reversible counter 10 is more pulses than is subtracted and the code at its output increases. This code using figure 11, a comparison is continuously compared with the threshold code on the bus 17 and, when it exceeds the threshold code, scheme 11 comparison produces a signal that writes a unit in D-flip-flop 13. This unit, acting on the tire 19 "Conflict", signals the presence of conflict in the network.For correct operation of the device requires that the pulse duration of odnovorov 5, 6 and 7 was shorter than the duration of the shortest own information pulse. The delay time in the delay element 9 should be small, just enough to explode in time of pulses to the counting inputs of the reversible counter 10. The pulse duration of the one-shot 12 to re-start must be greater than the largest interval between sostenimiento, when there is conflict detection.The device can change the initial code in the reversal of the counter 10, and the threshold code figure 11 comparison by changing codes on the tires 17 and 18.Thus, the conflict on the network is determined by the increase in the number of fronts on the total signal in the "Mono" 15 when the signal interference from multiple subscribers, regardless of whether signals are added or subtracted, securely conflict, as revealed the presence of both positive and negative edges of the level of the total signal.This device improves the reliability of detecting conflicts in contrast to devices that define the conflict only on the excess of the total signal threshold level, since the total signal may increase the level or decrease. DEVICE FOR DETECTING collisions IN a LOCAL area NETWORK containing transmitting and receiving transformers, and is diagnosed bus "Mono input devices respectively connected with the direct and inverse outputs of the transmitting transformer and direct and inverse inputs of the receiving transformer, the output of which is connected to input "Encoder", characterized in that, to improve the reliability of detection of conflicts in the local area network, enter a differentiator, a rectifier, a delay element, element, OR four one-shot, one-shot, a reversible counter, a comparison circuit and a D-flip-flop, and the output of the receiving transformer is connected through a differentiator to the input of the rectifier, the output of which through the first one-shot with a summing input of reversible counter bit outputs of which are connected with the first inputs of the comparison circuit, the output equals which is connected to the input recording D-flip-flop, bus sign "Conflict" devices are connected to the direct output of D-flip-flop, D-input connected to the bus logic unit, direct entry of the transmitting transformer is connected to the direct input of the second one-shot, with the negative input of the third one-shot and with direct input of the fourth one-shot, the outputs of the second and third odnovorov through the element OR delay element is connected to the subtractive input of the reversible counter, the input record which is connected to the inverted output of the fourth one-shot, the bus "Initial code" device connected with the information input of the reversible counter, Suhodol reset the D-flip-flop.
SUBSTANCE: device has commutation block, checked microcontroller, block of read-only memory devices of checked microcontroller, block of operative memory devices, PC, controlling microcontroller, block 7 of serial interface, indication block, commutation block of serial interface, block for forming a signal of starting setting of block for forming ROM addresses, block for forming addresses of Rom of checked microcontroller, block for decoding control signals, data-reading block, RAM recording block, block of memory access constants for checked microcontroller, block for forming addresses of checked microcontroller, block for forming start setting signal for controlling microcontroller, RAM reading block, block for forming RAM addresses and power buses.
EFFECT: higher efficiency.