DE1549525B1 - Method and device for evaluating a network, in particular for determining an optimal route - Google Patents

Description

1 '2

The invention is concerned with the problem of enabling displayed nodes and in the optimal connection between two states third line the establishment of a connection via of a particular system. This system is the mesh that is used to display the node determined by a number of variables, has to act to prepare that further simultaneously of to whom the time can also belong. For each state 5 the intermediate nodes indicated in this way are new of the system, these variables assume a certain- signals that advance in the sense explained, th value; the state is therefore by the total etc .; that - then that exit node be these values are defined. Anyone of these possible votes will be the first to agree to one of these signals States can be reached in a geometric space, whereupon the advancement of the that the same number of prostitutes- io signals are interrupted, and that finally in how the system contains variables. A second stage of the so-determined strike is then through a point in this space. gangslaiotenpunkt a connection to the undefined. future hub is established from which the

In concrete terms, the geome signal in question was emitted, which was the first to give the definite Australian Space formed by a network. The points reached 15 gangslaiotenpunkt.

of the room are through the nodes of the details of the method according to the invention

Network shown, while the connections between and the implementation of this method see these points represented by the mesh serving device proceed from the following evaluation. Spelling out. In the drawing shows

In the totality of these points, two 20 Fig. 1 are now a meshed network in one room Defined subgroups. One subgroup becomes two dimensions,

by a first number of points (starting Fig. 2 a schematic embodiment of the

points) and the other is formed by a second number of circuits to represent the nodes and points (arrival points). Each point of the meshes of the network according to Fig. 1,
first group can be connected to each point of the second 25 Fig. 3 an embodiment of a node group by a large number of ways point element corresponding to a node. The invention should now be that of the meshed network,

Point pair (starting point - arrival point) with Fig. 4 an embodiment of a mesh

be telt, the element of the optimal route connection corresponding to a mesh of the network, speaks. 30 Fig. 5 an embodiment of a weighting

In certain applications, the element (which gives the meshes of the network a certain weight value for the group of starting points as well as the group),
the arrival points to a single point each. Fig. 6 shows a variant of the invention for displaying the

shrinkage. optimal way.

In other applications, an output network can be used. In Fig. 1 is a meshed network in a room point at the same time represent an arrival point. shown with two dimensions.

The problem on which the invention is based is symbolized In this network, the node

thus of a very general nature. Special application points N1 to N10 different considered additions are, for example, the investigation of statuses in a given problem, while the urban traffic conditions, the distribution 4 ° meshes 1 to 13 transitions between an addition of goods or services, the calculation status and another status represent,
Minimal flight paths in overseas traffic, etc. The meshes are oriented and give on them

The invention is thus based on a method that makes sense of the connection between the individual devices Evaluation of a network with the help of pulses, nen states of the problem under consideration again. In where the nodes of the network correspond to points, 45 in the representation of FIG. 1, all meshes have one all of the states of a system with multiple single senses. However, you could also use a double variable To represent in a geometric space, to provide th sense by placing two parallel aligned which has the same number of dimensions as the opposite direction mesh provided System variable contains, and furthermore the measurements are.

see the network all between the individual 5 ° Nl is an exit node and N6 is a possible node point, elementary routes arrival node,
correspond. Next to each mesh name is in brackets

In such a method, the weight of the mesh in question is essentially the fact that a knot is The mesh 1 is, for example, with the weight point group that provides a first number of initial value 1, while the mesh 4 is a Represents dots, and another node weight value has 2, which two step progression groups, representing a second number of arrival point times between N 4 and N 5 , are indicated that corresponds to 4 during a first mesh. The mesh 9 has a stage at the same time of all initially indicated weight values 3, which three step progression times th arrival nodes signals are sent out of the mesh 9 provided between N 7 and N 8, which progress along the mesh corresponding to.

these nodes to intermediate nodes In Fig. 2, an output node A is a

run, which in turn are displayed, the arrival node B and an intermediate node display of a node primarily at point M being shown. The two elementary routes. Sequence has, the later reception of other signals 65 which a transition from node A to node By this displayed - allowing '■ nodes while point B, are to prevent this stage through the meshes 14 and 15, in the second place, the illustrated
step-by-step advancement of the signals from these nodes ^, B and M are each through

ORIGINAL INSPECTED

3 4

Identical node elements PA, PB and PM Fig. 5 shows the structure of a weighting, while the meshes 14 and 15 element, which serves to provide a mesh element with a certain weight by identical mesh elements F14 and F15. These are shown. weighting element contains a binary counter 38,

Each node element contains three outputs 5 whose input is connected to a gate 39, des-Sl, S 2 and S3 and three inputs El, E 2 and E 3, sen two inputs 40, 41 on the one hand with the output while each mesh element has two outputs S4 S3 of the node element are connected and S5, which can be connected to the input El of that represents the end of the mesh element to be provided with a certain end of the mesh under consideration, point element via an OR gate 17 and with io and on the other hand with the terminal 18 of the timer to the input E 2 of the beginning of the 19. The output of the binary counter 38 is connected to the node forming η EinMasche via an OR of a decoding gate 42, the gate 16 of which is connected. Furthermore, each output 43 with the input 32 of the with a be mesh element contains four inputs E4, E5, E6 and El. correct weight of the mesh element to be provided

The inputs E 4 and El can be connected to the outputs 15.

Sl and S2 of the beginning of the mesh under consideration The mode of operation of the device described

forming node element is connected as follows:

rend the inputs ES and E6 to the output 18 It is first shown in Fig. 2, from a timer 19 and to the output S3 of the node elements PA, PB and PM as well as the end of the considered mesh forming node 20 mesh elements F14 and F15 existing switching point element are connected. tion considered.

The inputs E 3 of the node elements are. The path to be investigated is that which makes it possible, with a second output 20 of the timer 19, to get from the output node A to the arrival link, node B. It runs over the

If the node end, B and M starts another 25 intermediate node M.

The display of the output node A takes place, corresponding mesh elements at their starting point by being connected by an output terminal (not shown) in the same way as, for example, the pointing device sends a constant confirmation signal from the mesh element F15 to the node element input terminal El des Node element PA PM is connected. In this way the additional 30 is fed. The display of the arrival node terminals 21, 22 and 23 with the input El, point B is carried out by a constant confirmation of the same output node belonging to the input terminal E 2 through a not shown output S 5 or input E 4 of each of the arrival display device of the knot mesh element connected. point element PB is supplied.

If the nodes A, B and M are the ends at 35 On the other hand, during the entire operation of their meshes, the time duration of the timers 19 alternately and constantly gates 17 contain a second input 24, which with the output of two signals T1 on Output 20 and Γ2 at output S 4 each to the same end node aisle 18.
element belonging mesh element is connected. The initial state of the memories of the node

F i g. 3 shows the structure of a node 40 point elements is also such that a locking signal on

element. It contains a bistable memory 25, output S 2 of these node elements before

the output of which bears the reference symbol S3 and des- tilting this memory appears. In the same way

sen input is connected to an AND gate 26, the initial state is the memory of the mesh

which has two inputs E 2 and E 3 . Furthermore, ent elements in such a way that a blocking signal at the output S 5

the nodal element holds a non-reversal 45 of these mesh elements before they are tilted

amplifier 27 occurs with an input El and an off memory.

gang Sl. The output of the memory 25 also has During commissioning, the node point

yet another connection S 2nd element PjB the appearance of the first signal Pl

Fig. 4 shows the structure of a mesh element. (The gate 26 [Fig. 3] is completely fed). This It contains a bistable memory 28 with a 50 node element is in this case the only one Output S 5. The input of this memory 28 is not tilted because the memory of the mesh elements an AND gate 29 is connected, to the five of which are inputs and the inputs E 2 of the other junction points, the inputs E 5 and E 6 belong. Furthermore, there is no confirmation signal (feed signal) hold an inverting amplifier 30 with an input E 7.

intended; the output is with one input 55. At this moment, the memory 25 of the toggles

of the AND gate 29 connected. A non-reversing node element PB and the output S3

amplifier 31 is with its input 32 possibly to this element feeds one of the inputs of the gate

connected to a weight element and with its 29 of the mesh element F15 via the input E 6

Connect the output to one of the inputs of Gate29 (Fig. 4).

bound. A second non-inversion amplifier 33 has 60 at the following signal Γ 2 are absent

an input 34 and its output is fed to one of the gate 29 via the input 34

one of the inputs of the gate 29 is connected. A locking signal fed all inputs of the gate 29.

AND gate 35 has an output S 4 and three. In this example it is assumed that the

Inputs, one of which does not contain any weighting elements with the output of the mesh element.

bistable memory 28, the other with "hold the input 65 and that as a result via the input 32

E 4 and the third no blocking is fed to gate 29 via a non-reversing amplifier. Another-

37 with an additional input terminal 36 on the side, the gate 29 is also via the input

is bound. E 7 fed because the node element PM,

5 6

which forms the beginning of the mesh element F15, output the output 51 of the node element-still is not in memory. After tes forms.

this memory 25 has not yet been flipped, provides the The mode of operation of this circuit is such,

Output 5 2 of this node element is not - that the signal that identifies the individual path stages, which after reversing through the 5, is only from node element to node

Inverse amplifier 30 of the mesh element F15 point element can progress, namely one

the gate 29 feeds. Following cycle of signals U1 and 172 that a-The first signal therefore causes the storage state to exclude the other and the propagation of a signal

of the mesh element F15 and at the same time feeds a control in the circuit. If it's a

the inputs of gate 35 and the output io acts as a "master-slave" circuit ("7-Z" circuit),

the gate 26 of the node element PM via which the signal cycle is through the sequence

Entrance EZ of this element. formed by two voltage values that correspond to the

In the case of the second signal 2Ί, the gate 26 of the node-speaking input of these known circuits

point element PM fully fed; this can be supplied. Is it the

The node element now goes into its 15 current circle with two bistable elements,

Memory status and feeds via its output 53 so you get the progress of the display signal,

the input E6 of the gate 29 of the mesh element by sending a first signal U 1 to the input 52 of the

Γ14. · First AND gate 50 is supplied, which results in

The sequence of individual operations to have that the above at the input El of the node transition from the node E to the node A 20 advances point element signal present and in the repeated in the same way as stored in the transition bistable element 53rd This signal from node 2? ziim junction M. The second cannot continue, since the second signal U 2 brings signal Γ 2 in this way the mesh element is missing. If you want to let the signal advance, under-F14 in the memory state; T1 definitely feeds one, if the first signal Ul is pressed and the second of its inputs of the gate 35 and its output 25 signal U 2 are fed to the input 55 of the AND gate 56. gang 55 and the input E 2 of the node- Since the other input 54 of this gate is fed by the element PA one of the inputs of the gate 26 of this tilted bistable element 53, the element tilts. bistable element 57 in turn. The signal appears

Since a memory of a therefore at the output 51 of the node element, outgoing mesh element is tilted from the output node, in 30 passes through a mesh member, and this moment then rindet a display signal once the at input El of the following Knotenpunktselemen-EingangEl of the node element PA züge- tes. There it is led by the AND gate 50 of this node. This signal is held at the output 51 point element, which in the absence of the node element PA and feeds one of the first signal U1 is not fed at all. Inputs of the gate 35 of the mesh element F14 35 The progression of the display signal therefore takes place via the input E4 of this element. This gate rhythm of the signals 171, U2. Since the examination 35 is fully activated, since there is no non-operating reversal, the signal that is supplied to the path on signal via the input 36 and has to draw goes from the starting point; this way the memory 28 is tilted. The display signal through- is therefore determined in the correct order, the gate 35 runs, arrives at the output 54 of the Ma- 40 One of the bistable elements of each node element F14, interspersed in the same way element can be used to identify the movement, the node element PM, the mesh element web will. Depending on whether the bistable F14 and the node element PB and appears elements gradually reset to zero or at the output 51 of the latter element. can be maintained in the tilted state

The materialization of the path from A to B shows the path either step-by-step or in a visible manner by removing the display signal and removing all previous steps. If one does not want to see the path in a montePA, PM and PB or a single display at the outputs 51 of the node elements, even with such a circuit, it is sufficient to display the signals E / l of the mesh elements F14 and F15. and Z72 at the same time. This is at

The described device shows at the end of the 50 "J-2 £" -circle or "master-slave" -circle not possible.

University search in one fell swoop - the path we were looking for borrowed.

between the starting point and the arrival point. The following description refers to FIG. 1.

Period. In certain applications it can also The problem posed is:

it may be desirable or necessary that this path takes the shortest route from the starting node iVl

gradually appears to determine either in a given 55 to arrival node N 6. in the

Rhythm or according to commands that differ from the previous example

are fed to the other device. Mesh elements here with a weight (corresponding to

This variant is obtained by adding a dimension in brackets to the node.

point element (Fig. 3) of the amplifier 27 see through.

an electronic circuit known as a “master-slave” 60. In the previous example, it was shown that a circle (“JK”) or is replaced by a circle, so that a mesh element is converted into the one illustrated in FIG. It consists of a memory state in a memory sequence that is taken from a first logical AND gate 50 with two inputs at the output 18 of the timer 19, 51 and 52 go, the first bistable circuit as soon as the node element that controls the end of 53 , the output of which is with one of the two 65 considered mesh elements, is in the memory inputs 54, 55 of a second AND gate 56 in understanding. To a mesh element with a tied. The output of this AND gate must be given a weight, so it is sufficient to connect the transfer to a second bistable circuit 57, whose transfer of this element to the memory state is not

at the first signal appearing at the output 18 of the timer 19 to control the memory state of the node element at the end of the mesh element under consideration, but only at the second, third or η-th signal according to the desired weight value.

For this purpose, the binary counter 38 (FIG. 5) counts a weighting element that includes the is assigned a weight to be provided mesh element, via which to the output 18 of the timer Terminal 41 connected to 19 shows the number of signals emitted at output 18 of timer 19. As long as the desired number of these signals is not reached, the weighting element holds over one output 43 connected to input 32 of the mesh element, a blocking signal at AND gate 29 upright.

If the number of signals emitted by the output 18 of the timer 19 reaches the weight value of the considered mesh element minus one unit, the weighting element cancels the blocking on, so that the mesh element can go into the memory state with the following signal, if no other lock occurs before that moment.

In Fig. 1, the meshes with the weight value 1 correspond to those mesh elements that have none Contain weight elements, while the meshes 4 and 9 correspond to those mesh elements that Contains weighting elements with 1 and 2 steps.

After displaying the output node Nl and the arrival node N 6, the first brings the output 20 of the timer 19 occurring signal Γ1 the arrival node N6 in the storage state. Then the first signal Γ 2 supplied by the output 18 of the timer 19 and following the above-mentioned signal Π leads only the mesh S into the memory state, since the mesh 10 is provided with a weight value.

At the second signal Π, the node N 5 is brought into the memory state. In the case of the second signal Γ2, only the loop 10 is passed into the memory state. At the third signal Tl then the node N 8, at the third signal Γ 2 the mesh 13; in this way it continues step by step in the rhythm of the signals Π and Tl .

At the fifth signal Π, the node N 3 is then moved into the memory state and the storage of the mesh 8 is prohibited.

This is because the mesh 8 provided with a high weight value has not yet been stored. Since it represents a path for connecting the nodes N 3 and NS which is longer than the path formed by the meshes 3 and 4, this mesh 8 must accordingly not be led into the memory state.

When the fifth signal T1 , the mesh 2 and the mesh 9 are stored.

At the sixth signal T1 , the nodes N1 and N7 enter the memory state, which prevents the meshes 6 and 7 emanating from the node N7 from being stored. When the sixth signal Γ 2, the loops 1 and 12 are taken into the memory state.

At the seventh signal T1 , the nodes N1 and N9 are brought into the memory state.

At this moment the output node N 1 is reached. The signals Π and Tl are blocked, and a signal is sent to the input El of the output node element, which is currently alternatively the non-reversing amplifier 27 of the node elements, the nodes Nl, Nl, N3, N4, N5 and N 6 and the AND gates35 of the mesh elements that form meshes 1, 2, 3, 4 and 5 passes through. This signal enables the display of the path formed by meshes 1 to 5 and shown in FIG. 1 is represented by the bold lines. Only this path is displayed, since meshes 6, 7, 8 and 11 are not in the memory state; the AND gates 35, which belong to the mesh elements of the meshes 6, 7, 8 and 11, are blocked.

In FIG. 1, the meshes 9 and 10 on the one hand and the meshes 12, 13 and 10 on the other hand are illustrated in bold lines. These meshes form two paths that do not end at the node Nl for the following reasons: The path formed by the meshes 9 and 10 does not end at the node IV1 because of the orientation 6, the storage of which is prohibited by the storage of the output node Nl. The path formed by the meshes 12, 13 and 10 does not end at the node Nl, since the mesh 1 is brought into the memory state before the mesh 11 and as a result the path formed by the meshes 11, 12, 13 and 10 is longer than the path of stitches is 1 to 5.

Only the shortest path from node Nl to node N 6 is thus displayed.

It can now happen that there are two paths between two nodes which represent the same number of steps (one step corresponding to the transmission of a signal T1 ), this number of steps being a minimum. These two nodes can be either the starting node and the arrival node or two intermediate nodes.

In such a case, the device shows both routes or both equivalent route parts. Man however, in this case you can also eliminate one of the two ways by giving the other one Gives priority.

For this purpose, consider in these two paths the two mesh elements emanating from the same node element which form the branch in question. The priority of one of these two mesh elements is then established by connecting the output S5 of the preferred mesh element to the input 36 of the non-preferred mesh element, the AND gate 35 of which is thus blocked.
Incidentally, certain meshes of the network can also be temporarily or definitely suppressed at any moment by applying a blocking signal to the input 34 of the mesh elements under consideration.

As already mentioned above, two nodes can be connected to one another via two meshes oriented in opposite directions, it being possible to provide different weighting for both directions.
The weighting of the meshes can also be modified by acting accordingly on the weighting elements.

In the example discussed, the problem contained a starting point and an arrival point.

009 523/249

In more general terms, the device described enables general problems to be solved with a first point group (starting group) and a second point group (arrival group), where the number of points in these groups is indifferent.

For example, if there are multiple exit junctions and a single arrival junction are, the device makes it possible to find out which output node it allows to reach the arrival hub with a minimal number of steps; also shows the device the corresponding path (s).

Conversely, if there is a single exit node and multiple arrival nodes are, the inventive device searches for the arrival node with a minimum Number of steps can be achieved; the device also indicates the corresponding route or routes.

Finally, if there are multiple exit nodes and multiple arrival nodes, then so the device makes it possible to solve the problem of the "affection" of one entity for another The whole by looking for the pair or pairs (exit node - arrival node) that are separated from each other by a minimum number of steps; it also shows the corresponding Ways on. As in the two previously explained cases, Here too, of course, the number of points considered can be up to 1 (i.e. one starting node and an arrival node), which again leads to the case according to FIG. 1 returns.

The device according to the invention can be used in a wide variety of fields, for example to regulate urban traffic.

The problem in this case is motorists to lead that in a larger area from all possible neuralgic points out on her Drive to destination. The guidance takes place along variable paths that are periodically re-determined and take into account the traffic density of the individual streets at every moment, as well as unpredictable ones Influences such as accidents, road works, etc. With each such calculation process, A group of paths was determined that were observed on the open into the neuralgic point. At the end of the work cycle, the optimal set is the Guide paths determined.

Every neuralgic point of the road network becomes represented by a node element; the streets or parts of streets, the neighboring neuralgic Connecting points are indicated by two parallel and (for possible consideration of the two possible traffic directions) oppositely directed mesh elements are shown.

Weighting elements can be assigned to each mesh element in order to give it a weighting to be awarded depending on the accepted criteria (size of the road, possible obstacles, Light control, speed limit, traffic congestion, etc.).

A cyclically operating device shows one after the other each neuralgic point as arrival point and all other neuralgic points as Starting points. One then only has to find the optimal route connections to the knowledge of the drivers bring, for example with the help of light panels or electromechanical devices in front of everyone Arranged crossing and controlled by the connections 54 of the mesh elements.

The device according to the invention can also be used use it to accelerate the speed at which public facilities (such as the fire brigade) are deployed, also to optimally solve evacuation problems in an emergency.

Further application possibilities are the calculation of the shortest corridor routes in overseas traffic, Dynamic programming problems as well as finding the critical path.

The device can furthermore be a subunit "registration center" of a complex, multi-tasking Represent memory, as shown for example in French patent 1381212 and its one function precisely in the search for the shortest sequence of intermediate sections between there are two situations.

It is understood that the structure of the invention Device not only on an electronic basis, but also with electromechanical, mechanical, hydraulic and pneumatic means can be done because the same logical functions for the individual components of the device technologically can be achieved in various ways.

Claims (13)

Patent claims: 1. Method for evaluating a network with the help of pulses, the nodes of the network Points correspond to all the states of a system with multiple variables in a geometric Represent space that has the same number of dimensions as the system variable contains, and furthermore, the meshes of the network all between the individual nodes possible, elementary routes, characterized in that one Node group representing a first number of starting points and another node group, representing a second number of arrival points indicate that during a first stage simultaneously from all arrival nodes initially indicated Signals are sent out which proceed along the meshes emanating from these nodes run, which in turn are displayed, with the display of a node in first and foremost, the subsequent reception to prevent other signals through these indicated nodes during this stage, secondly to enable the gradual advancement of the signals from these indicated nodes and thirdly the production to prepare a connection via the mesh that caused the display of the node, that also at the same time new signals from the thus indicated intermediate nodes going out advancing in the sense explained, etc .; that then that exit node which is reached first by one of these signals, whereupon the advancement of the signals is interrupted, and that finally in a second stage of the so particular exit node established a connection to the arrival node from which the signal originated that first reached the specified output node. 2. Apparatus for performing the method according to claim 1, characterized in that the network consists of a first group of circuits which form the node elements (PA, PM, PB) , and a second group of circuits which form the mesh elements (F 14, F15) consists. 3. Apparatus according to claim 2, characterized in that the mesh elements (F 14, V 15) have an orientation. ίο 4. Apparatus according to claim 2, characterized in that weighting elements (19, 38, 39, 42) are provided which cause the mesh elements (V 14, V 15) to be traversed in an integer number of steps. 5. Device for performing the method according to claim 1, characterized in that that a timer (19) sends out pulses that progress the signals in the network steer. 6. Device for performing the method according to claim 1, characterized in that that means are provided for displaying the route or routes selected. 7. The device according to claim 2, characterized in that the node elements (PA, PM, PB) are formed by a circuit which contains a bistable memory (25) which is controlled by an AND gate (26). 8. The device according to claim 3, characterized in that the mesh elements (F 14, V 15) are formed by a circuit which contains a bistable memory (28) controlled by an AND gate (29), that the output of this memory ( 28) and a first input of the AND gate (29) is connected via an OR gate (16) to an input of the AND gate (26) of the node element which forms the beginning of the oriented mesh element under consideration, or via a Inverting amplifier (30) with the output of the bistable memory (25) of the same node element, while a second input of said AND gate (29) is connected to the output of the bistable memory (25) of the node element at which the considered, oriented mesh element opens . 9. Apparatus according to claim 8, characterized in that the oriented mesh element (V 14, F15) contains a weighting circle which has a binary counter (38) which is controlled by an AND gate (39), one input of which is connected to the output of the bistable memory (25) of the node element is connected to which the observed, oriented mesh element opens and whose output is connected via a non-inversion amplifier (31) to a third input of the AND gate (29) of the mesh element. 10. The device according to claim 8, characterized in that the oriented mesh element (V 14, F15) contains a blocking circuit which has a non-inversion amplifier (33) whose output is connected to a fourth input of the AND gate (29) of this mesh element. 11. The device according to claim 5, characterized in that the timer (19) contains two signal outputs (18, 20), one of which with the second inputs of the AND gates (26) of the node elements (PA, PM, PB) and the other is connected to the fifth inputs of the AND gates (29) of the mesh elements (F 14, F15). 12. The device according to claim 6, characterized in that the devices used to display the selected path or paths contain a non-inversion amplifier (27) associated with each of the node elements (PA, PM, PB) , and an AND gate (35) , which is assigned to each of the mesh elements (F 14, F15) that the output of this AND gate (35) is connected via an OR gate (17) to the input of the non-inversion amplifier (27) which is assigned to the node element which opens at the considered, oriented mesh element, while the inputs of this AND gate (35) on the one hand with the output of the bistable memory (28) of the mesh element under consideration and on the other hand with the output of a non-reversing blocking amplifier (37) and with the output of the non-reversing amplifier ( 27), which is assigned to the node element that forms the beginning of the mesh element under consideration. 13. The apparatus according to claim 6, characterized in that the devices serving to display the selected path or paths contain a circle which is assigned to each node element (PA, PM, PB) and contains a first AND gate (50) with two in succession Inputs (51, 52), a first bistable trigger circuit (53), a second AND gate (56) with two inputs (54, 55) and a second bistable trigger circuit (57), the first and the second AND gate ( 50, 56) can receive an actuation signal (Ul, U2 ) at one input one after the other or simultaneously, that an AND gate (35) is still assigned to each mesh element, the output of which via an OR gate (17) with the other input of the first AND gate (50) of the circle is connected, which is assigned to the node element at which the viewed oriented mesh element opens, that furthermore the inputs of this gate on the one hand with the output of the bistable memory (28) of the mesh element under consideration and on the other its are connected to the output of a non-reversing blocking amplifier (37) and finally to the output of the second bistable breakover circuit (57) of the circle which is assigned to the node element which forms the beginning of the mesh element under consideration. For this purpose 2 sheets of drawings