JPS61139144A - Data communication supervisory system - Google Patents

Abstract

PURPOSE:To prevent the loss of the supervisory function as the whole of a system even if any monitor function is faulty, by discriminating whether each communicating equipment becomes abnormal or not in accordance with the comparison between contents of a main table and a subtable and performing this operation for plural communication at least. CONSTITUTION:A switch SW selects a transmission end S of a communication equip ment CE in accordance with the control based on the discrimination of the communica tion equipment CE if the communication equipment CE has the transmission right, but the switch SW selects a reception-side transmission line LR similarly if the has not the transmission right, and the switch SW connects the selected transmitted end S or reception-side transmission line LR to a transmission-side transmission line LS. If a communication equipment CEA has the transmission right and transmits data signals from the transmission end S to a communication equipment CEC and the communication equipment CEC receives them from a reception end R and transmits a response signal, this signal is given to the reception end R of the communication equipment CEA, and the data communication is performed between communication equipment CEA and CEC. Since data are transmitted in the order of priority level among communication equipment CEA-CED, the transmission of important data is not delayed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method in which a plurality of communication devices are connected in a loop through a transmission path and data is transmitted between each communication device. This relates to a method for monitoring whether or not the

[Conventional technology]

In such a communication system, the transmission right is acquired by transmitting a transmission right request signal, and the communication is carried out under the initiative of the communication device that has acquired this, so each communication is Means for monitoring whether a device is normal or not is used, and conventionally, monitoring is performed only by one specified communication device among each communication device.

[Problem that the invention seeks to solve]

However, with conventional means, only one communication device performs monitoring, so if a failure occurs in this communication device itself,
This has led to the problem that it is impossible to monitor the entire system.

[Means for solving problems]

In order to solve the above-mentioned problem, the present invention is constructed by the following means.

In other words, in the above communication method, the communication device that has acquired the transmission right is determined in response to a transmission right request signal during a certain monitoring period, and the communication device that has acquired the transmission right is stored in the sub-table corresponding to each communication device. A code indicating each communication device that does not acquire the right to transmit is registered as abnormal, and the contents of this sub-table are compared with the contents of the main table in which the results during the previous monitoring period are registered to determine whether each communication device is correct or not. Then, the contents of the main table are updated based on the contents of the sub-table, and the above operation is repeated in at least a plurality of communication devices.

[Effect]

Therefore, by comparing the contents of the main table and the sub-table, it is possible to judge whether each communication device is correct or not. However, the monitoring function of the entire system will not be lost.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to figures showing examples.

FIG. 2 is a block diagram showing the configuration of each communication device,
The communication device CB includes a terminal device TE and a transmitting/receiving section SR, and a receiving side transmission line LR made of an optical fiber is connected to the receiving end R of the communication device CB via a photoelectric converter 0/E.
Transmission side transmission line L of optical fiber via electro-optic converter E10
A switch SW is inserted between the communication device CE and the communication device CE, and selects the transmission end S of the communication device CE when it has the right to transmit according to the control based on the judgment of the communication device CE. If not, the receiving side transmission line LR side is selected and connected to the transmitting side transmission line Ls.

Therefore, if the switch SW selects the receiving end R side, the communication device CE is only capable of receiving and is excluded from the transmission path, and the signal from the receiving end transmission path LR is transmitted until that time. The data is transmitted to the side transmission path LB, and there is no transmission delay due to the intervention of the communication CE.

Furthermore, if the switch SW selects the transmission end S side, the image transmission paths LR and LS are separated, and the communication device CE is free to transmit and receive.

Fig. 3 is an overall block diagram based on the configuration of Fig. 2, omitting each converter 0/E and Elo, and connecting communication devices CE^~CED to each transmission line Ll-yL<) loop. In addition to connecting to
The selection status of A-8WD is shown in (4) to (2), and FIG. 4 shows the transmission/reception status of various signals corresponding to each stage of FIG. 2.

Here, first, as shown in FIG. 3 (4) and period (A) in FIG. 4, the communication device CIA has the transmission right,
Data signal I) TA is transmitted from the transmitting end S to the communication device CEc, while the communication device C receives it from the receiving end R.
If Ec sends a response signal ASC, this is the communication device C.
The signal is applied to the receiving end R of EA, and data communication is performed between communication devices CE^ and CEc. .

Then, when the communication device CE finishes transmitting the data signal DTA and receiving the response signal ASC, the communication device CE
In order to send the termination signal CDC to
Sending a confirmation signal CUc in response to receiving the end signal CDc,
Immediately after that, by setting the switch SWC to the receiving end R side, the communication device CEB-C
All EDs are in reception mode, where only reception is possible.

After the communication device CEA receives the confirmation signal CUc and after a predetermined period of time until the communication device CEc switches the switch SWc to the state (B), the communication device CEA receives the transmission right as shown in period (B) in FIG. The communication device CEA transmits a takeover signal cp indicating that the transfer is to be taken over as GLS, and the communication device CEA transmits this to all transmission paths Ll-%-
When received via L4, this communicates with other communication devices CEB-
The takeover signal cp is determined to have been received at CED.
In order to send an enabling signal OK indicating that the communication device CEa should be recognized as valid, this is received by another communication device CEB-CED, and the communication device CEa receives a takeover signal CP that has become valid.
Based on the judgment, if it has data to be transmitted to itself, it controls its own switching device SWa to
side, and enters the transmission mode shown in FIG. 3(C) and stands by.

Then, as shown in period (C) in FIG. 4, the communication device CEA switches the switch (
After the time required to reach state C), if the communication device CEA still has data to transmit, it sends a request signal C to which a unique address code is added indicating a request for transmission rights.
Furthermore, a priority code (■) indicating the priority of the transmission data is added to the TA, and these are sent to the request signal CTA (II
).

Then, this is received by the communication device CEB, and if the priority of the transmission data it owns is (1), it is determined that the communication device CEB should acquire the transmission right preferentially by comparison with this, and the communication device CEB Request signal CTn (with priority code (1) added and own address code added)
1) as GLS and is transmitted as shown in period (C) in FIG. 4, so that it is received by the communication device CEA.

The communication fcEh assigns the transmission right to the communication device C by comparing the received request signal CTB(T) with its own priority (Of).
It is determined that it should be taken over to EB, and the request signal cTn(()
After transmitting the signal as shown in period (C) in FIG. 4, the switch SWA is set to the receiving end R side, and the state shown in FIG. 3 (2) is established.

Request signal cTB(1)' transferred from communication device CIA
When the r communication device CEB receives the request signal CT, it determines that it has been granted the right to transmit, and sends the request signal CT.
After transmitting the validation signal OK that validates B(I), a response request signal C8D to which the destination address and self address codes are added is transmitted from the communication device CEn as shown in period 0) in FIG. Therefore, if the communication device CED is specified by the destination code, the device CEn will accordingly set the switch SWD to the sending end S side, and enter the state shown in FIG. Communication device C as shown in (g))
Since the ED sends the confirmation signal CUD, the communication device CEi
+ transmits the data signal DTB after receiving this confirmation signal, and the communication device CED starts transmitting the response signal ASD in response to receiving the data communication DTB.

Therefore, between the communication devices CEB and CED,
Data communication is performed, and each of the above operations is repeated in response to the end of data communication.
Since data is transmitted sequentially starting from high-priority data, there is no delay in transmitting important data.

In addition, takeover signal cp, request signal CTAQI), CTB(
GLS such as T), etc., each transmitting communication device receives and confirms what it has transmitted, and accordingly transmits an activation signal OK. -L
If a failure occurs in any of 4, it will not be able to confirm its own reception and will not send the activation signal OK, and communication devices after the failure location will not receive GLS. Only the communication device before this is prevented from going into a responsive state due to reception of GLS.

In addition to these signals CP1CT, GLS handles data such as time, alarm, and shared data in the same way. The signal OK is transmitted, and each communication device that receives the GLS temporarily stores it in the buffer memory and waits in response to receiving the GLS, reads and decodes the contents of the buffer memory in response to receiving the validation signal OK, and Actions are taken accordingly.

Therefore, the reception status of GLS is determined only by the communication device that sent it, and it is only necessary to send an activation signal OK, which simplifies the communication procedure and improves the overall communication speed. do.

FIG. 5 is a general flowchart showing the judgment and operation status by the terminal equipment TE in the communication device CIA-Cln, which is executed by a processor such as a microprocessor and memory provided in the terminal equipment TE.

In other words, through the initialization process 101, it is determined whether each communication RCEA-CED becomes a primary side that has transmission rights or a secondary side that does not have transmission rights, and depending on the result, the primary side ? '102 determination is made.

Note that step 101 is skipped when the power is turned on or the power supply recovers from a power outage, for example, when each communication device CEA-C
A waiting time is set for each ED according to its address number, and if no signal is received during this time, it is determined that it has the right to transmit, and if a signal from another is received, it is determined that it does not have the right to transmit.

If step 102 turns out to be Y (YES), the switch SW is controlled to perform "transmission mode setting 1111", and then performs "takeover signal" CP transmission 1112, and checks whether or not this is received via all transmission paths. Open signal %cp received? '11
3, and this is N (No) and a certain period of time % TR elapsed according to the timer in the processor? While '114 is N, step 113 and subsequent steps are repeated, and if υ step 114 becomes Y due to time-up of the timer, 1 transmission count = M until the maximum number of retransmissions M set by the counter in the processor is reached. ? '115 N through
Steps 112 and subsequent steps are repeated, and when step 115 becomes Y, the process moves to ``abnormality processing'' 116, where an alarm is sent out and displayed.

If step 113 becomes Y while step 115 is N, an enabling signal ``OK transmission'' 121 is performed, and whether or not this is received via all transmission paths is determined by an open signal ``OK reception?'' 122. While this is N, a certain period of time 'TR has elapsed?' as in steps 114 and 115.
``123 Y and もNumber of transmissions = M?'' 124 N
Step 121 and subsequent steps are repeated via Step 124
becomes Y, the process moves to step 116.

If step 122 becomes Y while step 124 is N, select the transmission data that has the highest priority among the transmission data it owns, and whisper a request signal to which a code indicating this priority is added. 131, and the same signal “CT received?
〃132, and while this is N, step 11
Same as 4,115, %TR elapsed for a certain period of time? ”133 Y
And ゝゝNumber of transmissions 2M? Step 131 and subsequent steps are repeated via N in 134, and in response to Y in step 134, the process moves to step 116.

If step 132 becomes Y while step 134 is N, it is determined whether or not this is the self-transmitted message using 1 self-CT? “
135, and depending on the Y of this, the enable signal 'O
K transmission "Perform 141, and as in steps 122 to 124, open signal % OK received?" While 142 is N, a certain period of time %TR has elapsed? '143 Y and 1 transmission count = M
? '144ON, steps 141 and subsequent steps are repeated, and as step 144 becomes Y, the process moves to step 116.

If step 142 becomes Y while step 144 is N, when new transmission data is generated, it is checked whether the priority of this data is higher than the priority transmitted in step 131. 1 Occurrence priority> Sent priority?
'151, and for the purpose of continuously transmitting data with the same priority, by comparing the highest priority among other data to be transmitted and the priority transmitted (in step 131). highest priority = source priority? If step 152 is N, step 112 and subsequent steps are repeated to give other communication devices a chance to acquire the transmission right, while if step 151 is Y, step 131
The following steps are repeated, and other communication devices are notified that there is transmission data with a higher priority than last time.

When step 151 is N1 and step 152 is Y, the turtle data transmission process 153 is performed, and steps 151 and subsequent steps are repeated, and until step 134 is N, the self-transmission data is sent in descending order of priority. If a request signal CT with a high priority is transmitted (from another communication device), and the result in step 135 is N, a transition is made to a reception mode to be described later.

Regarding the above, when step 102 is N, the switch SW
After controlling the Heron reception mode setting 161,
1 data sent to self? '162 is checked, and if it is Y, 1 transmission mode setting 1163 is performed as in step 111, and the request signal I from another communication device is
CT reception? '171 becomes Y, determine the priority of the self and the received one. Self priority ≦ reception priority? '
172, and if this is N, it is determined that its own transmission priority is not equal to or lower than other transmission priorities, and that it has the transmission right, and the process moves to step 131.

Further, if step 112 is Y, it is determined that the self does not have the transmission right, and the request signal CT received in step 171 is
as GLS and memory buffer area (hereinafter referred to as BF'
M)-BFM 4-CT 〃181 is used to store the content, then the content of the BFM is sent as is by the turtle reception CT transfer〃182, the air reception mode setting 1183 is performed in the same way as step 161, and the east data reception processing # After performing step 184 and performing 1 monitoring process "185,"
62 and subsequent steps are repeated.

Therefore, in step 185, each communication cover CE^~
Monitoring for CED is repeated.

FIG. 6 is a flowchart showing the details of step 153. 'Is the transmitted data GLS?''201 is judged, and if this is N, only 1 data transmission I202 is performed, but when step 201 is Y, -0LS transmission〃211
After doing this, check whether this is received via all transmission paths or not by 1 transmission GLS reception? monitored by '212,
While this is N, is the constant time %TR elapsed as in steps 114 and 115? '213 Y and "Number of transmissions =
M? Step 211 and subsequent steps are repeated via #214ON, and as step 214 becomes Y, step 11
1 abnormality processing" 215 is performed in the same manner as in step 6.

If step 212 becomes Y while step 214 is N, the activation signal ＼O
K transmission I221 and open signal 'OK reception? 〃222
%TR elapsed for a certain period of time via N? ``Discrimination of 223,
This YK corresponds to the number of transmissions = M? ' 224 through N's after step 221, and step 22
If the KOK signal is received while step 224 is N, step 222 becomes Y.

FIG. 7 is a flowchart showing the details of step 184, and asks whether the received data is GLS? Determine #301,
If this is N, -BFM for GLS←Clear” 302
While doing so, the address code ICfi is addressed to Tsukigame himself? '303 is checked, one content decoding (3o4) is performed according to Y of this, and steps 301 and subsequent steps are repeated.

Moreover, when step 301 is Y, the content is the activation signal %OK? '311 and if the result is N then %
BFM 4- GLS' 312 After storing GLS in BF'M, repeat steps 301 and after, and then, as step 311 becomes Y via Y in step 301, check whether there is vABFM content? '3 Check the old and read the contents of %BFM according to this Y (322). Is this the takeover signal 1cP? 1323
If the result is N, the process moves to step 304.

In addition, the response signal As, the end signal CD, and the confirmation signal CU
, response request signal CS, etc. are performed during the general procedure of data transmission and reception.

FIG. 1 is a flowchart showing details of step 185, in which the main table and sub-table shown below are provided as specific areas in the memory of the terminal device TE, and these are used.

In other words, the main table (hereinafter referred to as MT) and the sub-table (hereinafter referred to as ST) correspond to each communication device CEA to CEo. A code indicating a failure, and a code indicated by an x mark if an abnormality is similarly determined, are stored in correspondence with each other, and registration is performed based on these codes.

MT Table 2 ST MT 3'l' Note that the MTs in Table 1 are registered with the judgment results during the previous monitoring period, and the MTs in Table 3 are registered as they are in the first monitoring period in the next monitoring period. Used as MT for the table.

In Figure 1, 1 power supply ON? '401, and if it is Y, initialize it to %MT as all All X registration to SST as per I412
and the communication device %C according to the result of step 304.
Ei obtains transmission rights? '421 is determined, and if this becomes Y, 'MT's CEt-=X? Check '422, and if this is Y, 'CEi of MT-8T
Go to ○Register I431, for example, CEi = CIA
Now, let's assume the state shown in Table 2, 'CEi recovery notification〃432
As a result, the communication device CEI performs processing such as displaying that the communication device CEI has recovered from an abnormality to normality and storing in the memory a message that it can be selected as a communication partner.

Moreover, if step 422 is N, CEi of %ST
Go to x Registration I433, for example CEi = CEB
Now, as shown in Table 2, what is the timer time up?
While #441 is N, steps 421 and subsequent steps are repeated, and 1 judgment processing 442 is performed in response to Y in step 441, and the above operations are repeated through steps 162 and subsequent steps in FIG.

Therefore, for example, if the communication devices CEA and CEC sequentially acquire the transmission right and the communication devices CEB and CED do not acquire the right, the state shown in Table 2 will occur, and step 442 will determine the previous result as shown in Table 1. The contents of MT that had been shown are finally updated and become those shown in Table 3.

That is, in step 442, the contents of the following table are executed.

Table 4 Note that for the abnormality occurrence notification I, the same display as in step 432 and processing such as storing in the memory that the communication partner cannot be selected are executed.

Therefore, the above operation is performed for each communication device CEA to CED.
If all or at least a plurality of units perform this, an abnormality is determined based on the comparison at 1×registration 1 in Table 4, and a notification is made accordingly, and a recovery to normality is also notified in step 432. , these are performed in each communication device, so even if any communication device loses its monitoring function, the overall monitoring function will not be lost, and the reliability of the entire system will improve.

Then, step 431 is based on ST only, and MT's ○
Registration may be included in step 442 and step 432
The same effect can be obtained even if step 442 is similarly reduced.

Note that the priority may be determined by adding a code indicating the importance to each transmitted data, and the grade of this is (I),
In addition to (If), the destination address of the data signal DT can be determined according to the conditions. The reception mode may be maintained.

In addition, in FIG. 2, the switch SW may be an optical switch, and each converter 0/E and Ilo may be provided in the communication Eg, as long as each transmission line LR, LS passes an electric signal. The present invention can be modified in various ways, such as omitting the converters 0/E and I10 and using a general switch as the switch SW.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, since at least a plurality of communication devices individually monitor the correctness or failure of each communication device depending on the acquisition status of transmission rights, overall reliability is improved. A remarkable effect can be obtained in various data communications in which a large number of communication devices are connected in a loop, such as data communications between terminals of building management equipment.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing the details of the monitoring process, FIG. 2 is a block diagram showing the configuration of each communication device, FIG. 3 is an overall block diagram, and FIG. 4 is a diagram showing the transmission and reception status of various signals.
FIG. 5 is a general flowchart, and FIGS. 6 and 7 are flowcharts showing lower routines of FIG. 5. CE, CED to CEA...Communication equipment, S@...
・Transmission end, R...Reception end, SW, 5WA-8WD・
・φ・Switcher, LR...Receiving side transmission line, LS-...
- Transmission side transmission line, Lx-L4...transmission line.

Claims (1)

[Claims] A plurality of communication devices are connected in a loop through a transmission path, and a communication device that requires a transmission right sends a transmission right request signal by adding its own unique code, and in response to receiving the transmission right request signal. In a data communication system in which another communication device determines that it does not have the transmission right and the communication device that has transmitted the transmission right request signal acquires the transmission right, the communication device responds to the transmission right request signal during a certain monitoring period. determine the communication device that has acquired the transmission right, and register a code indicating each communication device that has acquired the transmission right as normal and a communication device that has not acquired the transmission right as abnormal in a sub-table corresponding to each communication device; The content of the sub-table is compared with the content of the main table in which the results during the previous monitoring period are registered to determine whether each communication device is correct or not, and the content of the main table is updated based on the content of the sub-table. A data communication monitoring method characterized by repeating the operation in at least a plurality of communication devices.