JPH01157637A - Communication equipment - Google Patents

Abstract

PURPOSE:To simplify and lower a device in cost by selecting an arbitrary line or plural lines among plural lines by means of a line selecting switch, connecting the lines to a transmitting and receiving part, and simultaneously, executing a communicating procedure by means of a control part. CONSTITUTION:The title device is equipped with communicating devices 1-4 to execute communications through lines 41-46, control parts 11-14 to control line selecting switch parts 21-24 and transmitting and receiving part 31-34 and to execute the communicating procedures, and transmitting and receiving parts 31-34 to transmit and receive line selecting switch part 21-24 signals to connect the arbitrary one or plural lines among plural lines 41-46 to the transmitting and receiving parts 31-34. The line selecting switch parts 21-24 are controlled by the control part 11-14, the arbitrary one or plural lines 41-46 are selected among plural lines 41-46, simultaneously, the communicating procedures are executed, and thereby, the communications with the arbitrary plural communicating devices can be executed by one of transmitting and receiving parts 31-34. Thus, the device can be simplified and lowered in price.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a communication device that performs communication by connecting communication lines horizontally (mesh type).

[Prior Art] FIG. 11 is a block diagram showing a conventional communication device. In the figure, 1 to 4 are communication devices that perform communication; 41 to 4;
6 is a line connecting communication devices 1 to 4, 191 to 2
00 is a transmitting/receiving unit that transmits and receives signals and data, 181
- 184 are transmitting/receiving units 191 in the communication devices 1 to 4, respectively.
200. Each of the communication devices 1-4 includes one control section 181-184 and transmitting/receiving sections 191-200 equal to the number of connected lines.

Next, the operation of the above conventional communication device will be explained. Each of the control units 181 to 184 establishes a communication link with the control units 181 to 184 of the communication devices 1 to 4 on the other side connected via the lines 41 to 46 by driving the transmission/reception units 191 to 200. . For example, when communicating between communication device 1 and communication device 2, the control unit 18 of communication device 1
The controllers 182 of the communication device 1 and the communication device 2 drive the transmitter/receiver units 191 and 194, respectively, and establish a communication link via the line 43. In addition, when communicating between the communication device 1 and the communication device 3, the control section 181 of the communication device 1 drives the transmitter/receiver section 192, and the control section 183 of the communication device 30 drives the transmitter/receiver section 197. to establish a communication link.

Link establishment operations are similarly performed between other communication devices 1 to 4.

[Problems to be Solved by the Invention] In the conventional communication device as described above, the transmitting/receiving units 191 to 200 correspond to the lines 41 to 46 as described below.
In addition, the control unit 18 of the communication devices 1 to 4- is required.
1 to 184 control a plurality of transmitting/receiving units 191 to 200, the control algorithm becomes complicated and the device becomes expensive.

The present invention has been made to solve these problems, and an object thereof is to obtain a communication device that can easily establish communication links between a plurality of communication devices while suppressing an increase in hardware of the communication device.

[Means for Solving the Problems] A communication device according to the present invention includes one transmitting/receiving section in each communication device and selecting any one or more lines from a plurality of lines to perform the above-mentioned transmitting/receiving. The transmitter/receiver includes a line selection switch section connected to the transmitting/receiving section and the line selection switch section to execute communication procedures.

[Function] In the communication device of the present invention, the control unit controls the line selection switch unit and selects any one or more lines from among the plurality of lines while executing the communication procedure, so that one To enable a transmitting/receiving unit to communicate with any plurality of communication devices.

[Embodiment] FIG. 1 is a block diagram showing a communication device that is an embodiment of the present invention. In the figure, 1 to 4 are lines 41 to 4.
Communication devices 11 to 14 communicate with each other via 6, control units 11 to 14 control the line selection switch units 21 to 24 and transmission/reception units 31 to 34 to execute communication procedures, and 21 to 24 indicate a plurality of lines 41 to 46. a line selection switch section 31 that connects any one or more of the lines to the transmitting/receiving sections 31 to 34;
-34 are transmitting/receiving units that transmit and receive signals.

FIG. 2 is a specific circuit configuration diagram of the line selection switch unit in the communication device of FIG. 1. FIG. 2 shows a specific circuit of the line selection switch section 21 of the communication device 1. As shown in FIG. In the figure, 25 to 27 are line selection switches 51 to 5 for connecting the lines 41 to 43 to the transmitter/receiver 31, respectively.
3 is a line selection signal line for transmitting a control signal for connecting any one or more lines among the plurality of lines 41 to 43 to the transmitter/receiver 31; 61 and 62 are the transmitter/receiver 31, respectively;
The transmitting unit, receiving unit, 71 to 73 in the internal circuit transmit the transmission signal of the transmitting unit 61 to the lines 41 to 43 by the control unit 11 outputting a logical value "1" to the line selection signal lines 51 to 53. On the transmitting side A, ND, and 81 to 83, the control unit 11 outputs a logic value "1" to the line selection signal lines 51 to 53, so that the received signals of the lines 41 to 43 are sent to the receiving unit 6.
The receiving AND gate 84 is a receiving OR gate that simultaneously puts the connected lines in the receiving state.

FIG. 3 is a specific circuit configuration diagram of the line selection switch unit in the communication device of FIG. 1. FIG. 3 shows a specific circuit of the line selection switch section 22 of the communication device 2, and its configuration is the same as that of the communication device shown in FIG. In the figure, 54 to 56 are line selection signal lines, 63 is a transmitter,
64 is a receiving section, 65 to 67 are line selection switches, and 74-
~76 is the transmitting side AND key 1・, 85~87 is the receiving side A
ND gate 88 is a receiving side OR gate.

Next, the operation of the communication device which is an embodiment of the present invention will be described. Control units 11, 12, 13 shown in FIG.
．． 14 controls the line selection switch units 21, 22, 23, and 24, selects one or more arbitrary lines, and transmits and receives commands/responses.

By the way, in the communication device of the present invention, the communication devices 1 to 4-
One of them is the primary station, and the other communication devices to 4 are the secondary stations, and communication is performed between the primary station and the secondary station. In FIG. 1, the communication device 1 is the primary station. , communication device 2, 3.4 is 2
It's the next game. In the communication device 2.3.4, initial information is set that the local station is a secondary station, but information regarding stations other than the local station is not set. In addition, the communication device 1
Since its own station is the primary station, it knows that all other stations are secondary stations.

Therefore, in the communication link, the primary station sends a line specification command to the secondary station, the secondary station returns a line specification response, and the 1st station sends a line specification command to the secondary station.
The next station sends a link establishment command to the secondary station, and the secondary station returns a link establishment response. The secondary station cannot communicate until a link is established. Further, after the link is established, the primary station polls each secondary station at least once within a certain period of time, and the secondary station returns a response to the polling.

For example, in the following example, communication device 1, which is a primary station, is communication device 2,
Consider the case of communicating with 4. In FIG. 2, the control unit 11 of the communication device 1 selects the line 41.43 by outputting a logical value "1" to the line selection signal line 51.53. Next, the transmitter 61 transmits a line designation command to the selected lines 41 and 43, and when a response is returned, a link establishment procedure is executed. Even after the link is established, the communication device 1 continues to select and poll the same lines 41 and 43 as before the link was established.

On the other hand, in Figure 1, the communication device 2, which is the secondary station, does not know which line the communication device is connected to is the primary station before the link is established. Therefore, in FIG.
2 connects all the lines 43, 44.45 connected to the communication device 2 to the transmitting/receiving section 32 by outputting a logical value "1" to all the line selection signal lines 54, 55, 56.

Therefore, when receiving the line designation command, the control unit 12 turns on the line selection switch 65 according to the line selection switch number corresponding to the line to be connected at the secondary station ζ listed in the line designation command. By outputting a logical value "1" to the line selection signal line 54 and conversely, outputting a logical value "0" to the line selection signal line 55, 56, only the line 43 is connected to the transmitter/receiver 32, Return a response to the line specification command and execute the link establishment procedure.

Once the link is established, the control unit 12 performs subsequent communications over the line 43 on which the link establishment procedure was executed. The communication device 4 also operates in the same way as the communication device 2, but as shown in FIG. Keep line 41 selected.

FIG. 4 is a flowchart showing the link establishment operation of the communication device set as the primary station in the communication device of FIG. FIG. 4 is a flowchart showing an example of the operation of the communication device 1 set as a primary station. In the figure, TI, T2
．． T3 is the time, 91 is a line specification command for selecting the line 43 destined for the communication device 2, 92 is a link establishment command for the communication device 2, 93 is a line specification command for selecting the line 4-1 for the communication device 4, 94 is a link establishment command addressed to the communication device 4, 95 is a response to the line specification command 9I, 96 is a response to the link establishment command 92, 97 is a response to the line specification command 93, 98 is a response to the link establishment command 94, 99 is a link establishment A command 100 is a response to the command 99 for the subsequent communication device 2.

The communication device 1 set as the primary station starts a line selection operation from time T1. The operation of the communication device 1 after time T1 is as follows.

[1] At time T1, the line designation command 91 selects the line 43.41 and attaches the address addressed to the communication device 2.
Send. Communication devices 2 and 4 receive the line designation command 91, but only communication device 2 determines that it is addressed to its own station, selects line 43, and returns a response 95. When the communication device 1 receives the response 95, it transmits a link establishment command 92 to the lines 43 and 41. Similarly to the above, only the communication device 2 determines that the communication is directed to its own station, and sends the response 96 back to the already selected line 43. Communication device 1 and communication device 2 establish a link through the above procedure.

[2] At time T2r, communication device 1 is connected to line 43.
．． 41 and sends a line designation command 93 with an address addressed to the communication device 4.

Communication devices 2 and 4 receive the line designation command 93, but only communication device 4 determines that it is addressed to its own station, and
A response 97 is sent back to 1. However, since the communication device 4 is connected to only one line, the line 41 is fixedly connected and no selection operation is necessary. Upon receiving the response 97, the communication device 1 issues a link establishment command 94.
is sent to line 43°41. Similarly to the above, only the communication device 4 determines that the communication is directed to its own station, and returns a response 98 to the line 41. Communication device 1 and communication device 4 establish a link through the above procedure.

As described above, the communication device 1, which is a primary station, establishes a link with each communication device 2, 4, which is a secondary station. Communication after link establishment is performed as follows.

When a transmission request addressed to the communication device 2 occurs at time T3, the communication device 1 transmits a command 99 addressed to the communication device 2 to the line 43.41. After the link is established, communication device 2
Since the line 43 is fixedly selected and is in the receiving state, the command 99 can be received, and a response 100 in response to the command 99 can be received.

FIG. 5 is a diagram showing a frame format showing an HDLC transmission frame in the communication device shown in FIG. Fifth
The figure shows HDLC (High
h Level DataLink Contr
ol) frame format I. In the figure, 101 is an address section, 102 is a control section, and 103 is an information section.

Fe2 (Frame Ceck 5e
quence) is the frame check sequence.

Figure 6 shows the H between the primary station and secondary station in the first communication device.
FIG. 3 is a time series diagram showing commands and responses of DLC.

FIG. 6 is a diagram showing the line selection procedure and link establishment procedure by the HDLC. In the figure, 104 is an XID (Exchange
Identification) command, 105
106 is an XID response that can be used as a line specification response, and 106 is an SNRM (
Set Normal Re5ponse Mo
de) command, 107 is a UA (Unnumbered Ack no
w l e d g e m e n t ) response.

Next, the link establishment operation will be explained with reference to FIGS. 5 and 6 above. The primary station puts the line selection switch number corresponding to the line to be connected at the secondary station in the information section 103 of the XID command 104, and transmits it from the primary station to the secondary station. The secondary station that receives the XID command 104 uses the address section 101 to determine whether it is addressed to its own station, and if it is addressed to its own station, it selects a line according to the line selection switch number listed in the information section 103 and sends the XID command. Response 1
Return 05. 1 that received XID response 105
The next station sends SNRM to the secondary station indicated in the address field 101.
Send command 106.

The secondary station that receives this SNRM command 106 uses the address section 101 to determine whether the command is addressed to its own station, and if it is addressed to its own station, returns a UA response 107. Through the operations described above, a link is established between the primary station and the secondary station. Note that the above operation is for B
It is clear that this can be realized using an ASIC procedure or the like.

FIG. 7 is a flowchart showing the link establishment operation of the communication device set as a secondary station in the communication device of FIG. Figure 7 shows communication devices 2, 3.4 set as secondary stations.
A flowchart of the link establishment operation is shown, and the operation will be explained according to the element number of this flowchart.

Step 110: Put all lines into reception state.

In step 11, the process waits for a line designation command to be received.

Step 112: Upon receiving the line designation command, the process proceeds to step 113.

Step 113: Check whether the received line designation command is addressed to the own station. If it is addressed to the own station, proceed to step 114; if not, return to step 111.

Step 114 = Select only one line according to the line selection switch number included in the received line designation command.

Step 115: Return a line specification response.

Step 116: Start a timer to detect failure to receive a link establishment command.

Step 117: Wait for reception of link establishment command.

Step 118: Upon receiving the link establishment command,
Proceed to step 119.

Step 119: Check whether the received link establishment command is addressed to the own station. If it is addressed to the own station, proceed to step 120; if not, return to step 117.

Step 120: Returning a link establishment response,
Finish executing the link establishment procedure.

Step 121: If the link establishment command cannot be received and the timeout occurs, the first step 110
Return to

FIG. 8 is a flowchart showing a link establishment operation of the communication device set as a primary station in the communication device of FIG. FIG. 8 shows a flowchart of the link establishment operation of the communication device 1 set as the primary station. Note that the flowchart in FIG. 8 extracts and shows the operation for the communication device 1 for which a link has not been established, and is parallel to the polling operation for other lines for which a link has been established (shown in FIG. 10, which will be described later). It may also be executed.

Step 130: Select any one or more lines.

Step 131: Clear the number of transmission retries.

Step 132: Send a line designation command to the line for which no link has been established.

Step 133: Start a timer (1) for detecting that a line designation response cannot be received.

Step 134: Wait for reception of line specification response.

Step 135 When a line specification response is received while waiting for reception of a line specification response in step 134, the process proceeds to step 140.

Step 136: If the timer (1) times out without receiving a line specification response, step 1
Proceed to 37.

Step 137: Increment the number of transmission retries by "1".

Step 138: If the number of transmission retries does not exceed the specified value, proceed to step 139 and repeat the retries. On the other hand, if the number of transmission retries exceeds the specified value, processing for the line is stopped and the process proceeds to step 148. The line in question will be placed in a line failure state and will not be subject to subsequent link establishment operations.

Step 139: Send the line designation command again.

Step 140: Repeat and clear the number of transmission retries.
.

Step 141: Send a link establishment command.

Step 142: Start a timer (2) for detecting that a link establishment response is not received.

Step 143: Wait for reception of link establishment response.

Step I44: If a link establishment response can be received in the state of waiting for reception of a link establishment response in step 143, it is determined that the link of the line has been established. Proceed to step 148 to check whether link establishment for all lines has been completed.

Step 145 = If the timer (2) times out without receiving a link establishment response, proceed to step 146.

Step 146: Increment the number of transmission retries by "1".

Step 147: If the number of transmission retries does not exceed the specified value, return to step 144- and repeat the retries.

If the number of transmission retries exceeds the specified value, processing for the line is stopped and the process advances to step 148. The line in question will be placed in a line failure state and will not be subject to subsequent link establishment operations.

Step 148: Check whether there is a line with no link established;
If "no", the process ends; if "yes", the process returns to step 131 and continues execution of the link establishment procedure for the line for which the link has not yet been established.

FIG. 9 is a flowchart showing the operation of the communication device set as a secondary station in the communication device of FIG. 1 after link establishment. Figure 9 shows the communication device 2 of the secondary station after the link is established.
, 3.4 is a flowchart showing the operation of FIG.

Step 150: In preparation for a failure of the primary station due to a line failure or movement of the function of the primary station due to such failure, a timer is activated to detect a command non-reception state.

Step 151: Wait for command reception or timeout event.

Step 152: If a timeout occurs while waiting for an event, it is assumed that a link failure has occurred, and the link re-establishment operation shown in FIG. 7 is restarted.

Link re-establishment is performed for all lines.

Step 153: If a command is received while waiting for an event, the process proceeds to step 154.

Step 154: Process according to the command and proceed to step 155.

Step 155: Return the response. The reception of the command and the return of the response means that the link is maintained in a normal state, so the process returns to step 150, restarts the timer, and waits for the next event.

FIG. 10 is a flowchart showing the operation of the communication device set as a primary station in the communication device of FIG. 1 after link establishment. FIG. 10 is a flowchart showing the operation of the communication device 1 of the primary station regarding the link after the link is established. If there are multiple established links, the 10th
The processing of the diagrams is performed in parallel and independently of the links here.

Step 160: Start a timer (1) for periodically polling.

Step 161: Wait for the occurrence of a transmission request or a timeout event.

Step 162: If the timer (1) for periodically polling is set, step 162.
Step 163. Step 164. The process proceeds to step 165 to transmit a polling command, and then enters step 166 to receive a polling response.

Step 163: Clear the number of transmission retries for the line.

Step 164: Start timer (3) to detect non-reception of polling response.

Step 165: Send a polling command.

Step 166: Wait for reception of polling response.

Step 167: Upon receiving the polling response,
The ring is confirmed to be normal.

Step 168: When the timer (3) times out without receiving a polling response, step 169
Proceed to.

Step 169: Increment the number of transmission retries.

Step 170: If the number of transmission retries does not exceed the specified value, the process returns to step 164 to continue the retry operation. On the other hand, if the number of transmission attempts exceeds the specified value, it is regarded as a link failure and a link re-establishment operation for the line in question (see FIG. 8) is started.

Step 171 When a transmission request occurs in the event waiting state of step 161, the process shifts to transmission processing.

Step 172: Clear the number of transmission retries.

Step 173: Start a timer (2) for detecting non-reception of a response.

Step 174: Send the command.

Step 175: Enter into response waiting state.

Step 176: When a response is received in the response waiting state, the process returns to step 161 in the event waiting state.

Step 177: In the response waiting state, when the timer (2) times out without being able to receive a response, the process proceeds to step 178.

Step 1782: Increment the number of retry attempts for transmission on the line.

Step 179: If the number of transmission retries does not exceed the specified value, retry command transmission. - On the other hand, if the number of transmission retries exceeds a specified value, it is regarded as a link failure and a link re-establishment operation (see FIG. 8) for the line in question is started.

[Effects of the Invention] As described above, the present invention provides a communication device in which a line selection switch unit selects any one or more lines from a plurality of lines and connects the line to a transmitting/receiving unit, and the control unit Since the communication procedure is carried out, only one transmitting/receiving section is required in the communication device, which provides excellent effects such as simplifying the device and allowing it to be constructed at low cost.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram showing a communication device that is an embodiment of the present invention, FIGS. 2 and 3 are specific circuit configuration diagrams of a line selection switch section in the communication device of FIG. 1, and FIG. 4 is a flowchart showing a link establishment operation of a communication device set as a primary station in the communication device of FIG. 1, FIG. 5 is a diagram showing a frame format of an HDLC transmission frame in the communication device of FIG. 1, and FIG. The figure is a time series diagram showing the HDLC command and response between the next station and the secondary station in the communication device shown in FIG. 1, and FIG. FIG. 8 is a flowchart showing a link establishment operation of a communication device set as a primary station in the communication device of FIG. 1. FIG. 9 is a flowchart showing a link establishment operation of a communication device set as a secondary station in the communication device of FIG. FIG. 10 is a flowchart showing the operation after link establishment of the communication device set as the primary station in the communication device of FIG. 1, and FIG. 1 is a block configuration diagram showing a conventional communication device. In the figure, 1 to 4... communication device, 11 to 14°18
1-184... Control unit, 21-24... Line selection switch unit, 25-27. 65-67... Line selection switch, 31-34, 191-200... Transmission/reception unit, 4
1-46...Line, 51-56...Line selection signal line, 61...-Transmission section, 62...Reception section, 71-76.
・Sending side AND gate, 81~83.85~87...
・Receiving side AND gate, 84.88...Receiving side OR gate, 91.93...Line specification command, 92°9
4...Link establishment command, 95-98,100...
・Response, 99... Command, 101... Address section, 102... Control section, 103... Information section, 1
04...XID command, 105...XID response, 106...SNRM command, 107...U
A-Tresence, 110-121. 130-148.
150-155, 160-179...steps. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (2)

[Claims] (1) In a communication network in which a plurality of communication devices are connected to each other via lines, the communication device has one transmitting/receiving unit that performs transmission and reception between each communication device, and an arbitrary one from among the plurality of lines. A communication device comprising: a line selection switch unit that connects one or more lines to the transmitting/receiving unit; and a control unit controlling the line selection switch unit and the transmitting/receiving unit to perform communication operations. Device. (2) One of the plurality of communication devices mentioned above is designated as a primary station, and the others are designated as secondary stations, and the control unit of the communication device set as this primary station controls one or more connected lines. between a first means for simultaneously selecting one or more lines from which a data link is to be established, and, once the lines have been selected, a communication device set at the one or more secondary stations; and a second means for establishing a data link to the above-mentioned second means.
The control unit of the communication device set as the next station simultaneously selects all the connected lines and waits for the line designation command sent by the communication device set as the primary station to be received. When this line designation command is received, a third line selection command is added to the line designation command that selects only one line according to the line selection switch number corresponding to the line to be connected at the secondary station set by the primary station. and a fourth means for establishing a data link on the selected line, and after the link is established, monitors the continuous no-reception state on the line where the link has been established, and when the no-reception state is detected, the fourth means establishes the data link again on the selected line. 2. The communication device according to claim 1, further comprising: fifth means for transferring processing to the means.