JPS61140247A - Transmission right takeover system of data transmission - Google Patents

Abstract

PURPOSE:To reduce overall communication required time on data transmission by confirming the transmission state of a transmission right request signal through the own judgement only and transmitting an effective signal and using a switch to select a reception side transmission line thereby obtaining the reception mode. CONSTITUTION:A reception side transmission line LR comprising an optical fiber is connected to the reception end R via a photoelectric converter O/E, and a switch SW is inserted between the line LR and a transmission side transmission line LS comprising an optical fiber via an electrooptic converter E/O. Then in response to the control based on the judgement of a communication equipment CE, when the own transmission right exists, the transmission end S of the CE is selected, and when no transmission right exists, the LR is selected and then the CE is connected to the LS. In throwing the SW to the position of the S, both the transmission lines LR and LS are separated and the transmission/reception of the CE are attained freely.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a communication method in which a plurality of communication devices are connected in a loop through a transmission path, and data is transmitted in a fixed direction. This article relates to a transmission right handover method used when handing over the transmission right from one communication device to another communication device.

[Conventional technology]

In such a communication system, one of the communication devices has the right to transmit data, and it takes the initiative to send and receive data (l!t) to the other party's communication device. A communication device sends a global signal (GLS) to all seven communication devices after communication by another device is completed
), and in response to reception of this, other communication devices that do not require the entire transmission right relinquish the transmission right.

[Problem that the invention seeks to solve]

However, in the conventional method, the reception of fl and GLS is performed by all other communication devices, and after confirming everything, a specific communication device transmits a confirmation signal from each communication device. This creates a problem in that the time required for this process slows down the overall communication speed.

[Next method to solve the problem]

In order to solve the above-mentioned problem, the present invention is configured as follows.

That is, in the above-mentioned communication method, a switch is provided that selects the receiving side transmission path connected to the receiving end of the communication device and the transmitting end of the communication device and connects it to the sending side transmission path. Compare the transmission priority with other transmission priorities, and when the transmission priority of oneself is not equal to or lower than the other transmission priority, select the transmission turtle by the switch and transmit the own transmission right request signal, If this own transmission right request signal is received, it is determined that the transmission right request signal has been received, and then an enabling signal for validating the transmission right request signal in another communication device is transmitted, and if the own transmission right request signal is If n is not received, it is determined that there is no right to send,
The receiving side transmission path is selected by a switch in response to reception of an enabling signal from another device.

[Effect]

Therefore, based solely on its own judgment, the transmission status of the transmission right request signal is confirmed, and the corresponding enabling signal is transmitted only in some of the other communication devices. A transmission mode in which reception of the transmission right request signal is blocked and transmission is possible by selecting the transmitting end using the switch, and a reception mode in which only reception is possible by selecting the receiving side transmission path by the switch .

[5! Weaving example〕 Below is ′! ! The present invention will be explained in detail by way of example.

Figure 2 is a block diagram showing the configuration of each communication device.The ROM communication device CE consists of a transmitting/receiving section SR made of layer end equipment TE. It is connected via converter 0/E, and a switch SW is inserted between this and the transmission line Ls on the source fiber's transmitting side via electro-optical converter E10ffi, and control based on the judgment of Tsushin & CE is installed. Accordingly, when it has the transmission right, it selects the transmission end St of Tsushin ACG, and when it does not have the transmission right, it selects the reception side transmission line Lm98, and connects it to the transmission side transmission line Ls. .

Therefore, if the switch selects the receiving end R11,
The communication device CE becomes capable of only receiving and is excluded from the transmission path, and the signal from the reception side transmission path LR is immediately transmitted to the transmission side transmission path Ls, and there is no transmission delay due to the intervention of the communication gII LCE. It becomes something that does not occur.

However, if the switch SW selects the transmitting end 5lllI, the image transmissions Nt Lx and LB are separated, and the image can be freely transmitted to and received by the communication device cE.

The third factor is an overall block diagram based on the configuration of FIG. 2, in which the converters 0/E and Elo are omitted, and the communication devices CEA-CED are connected to the respective transmission lines Ll-L4 in an ecrug shape. In addition, the selection status of the switching device 5WA-SWD according to the transition of the communication status is shown in the figure. It shows the sending and receiving status.

First, let us consider the prisoner period in Figure 3 and the period in Figure 4 (4
), the communication device CEA has the transmission right and transmits the data signal DTAt from the sending end S to the communication device CEc, and receives it from the receiving end R and sends it to the communication device CEc.
If c is the response signal ASc t-sender, it is given to the receiving end R of the communication device CEa, and the communication devices tcE^ and C
Data optimization is performed between Ec and Ec.

Next, when the communication device cE^ finishes transmitting the data signal DTA and receiving the response signal ASc, the communication device cE^ sends a completion signal CDcf to the communication device CEc.
CEc sends a confirmation signal C in response to receiving the end signal CDc.
Immediately after that, the switch SWc is set to the receiving mR side, as shown in Fig. 3 ω), and the communication devices CE B ” and CE o enter the receiving mode of receiving only. .

After the communication device CEA receives the confirmation signal CUc,
After a predetermined period of time has elapsed until the communication device cEc changes the switching device SWc to the state of ), a takeover signal CP'f indicating that the transmission right is to be taken over as shown in period Q3) in FIG.
cGLS, and when the communication device CE^ receives this through all the transmission paths Ll-L4t-, it determines that this has been received by the other communication devices CEB to CEo, and recognizes the takeover signal CPk as valid. This is received by the other communication devices CEa′ to CED, and the communication device CEa
If it has data to be transmitted to itself based on the judgment corresponding to the 9 takeover signal CP that becomes valid, it controls its own switching device SWa' to become the transmitting end S*, and as shown in FIG. mode and wait.

Then, as shown in period 0 of the fourth factor, the communication device CEA switches the switch t-(C
), and when the communication device CE^ outputs all transmission data, a priority code (( ID' is added, and these are sent to the request signal C.
Transmit as TA((1).

Then, this is received by the communication device CE a,
If the priority of the transmission data owned by the communication device CE is not (1), the communication device CE determines that it should preferentially occupy all the transmission rights by comparison with this, and the communication device CE! I is the priority code (I)
The request signal CTJI(I) is transmitted as kGLs during the period (Q) in FIG. 4, and is received by the communication device (J).

The communication device CEA compares the received request signal CTi5(I) with its own priority level ■, and determines the transmission right communication device ff1.
It is determined that it should be taken over to tcEB, and the request signal CTB (
I) During the t-period of FIG. 4 (as shown in Q), the signal is transmitted until i), and the switch SWA'fr is set to the upper side of the receive mode as shown in FIG. 3, 0.

The next requested redemption code CTs (1
) is received by the communication fit CE B, it is determined that the right to transmit has been granted to itself, and the request signal CT B (1) t- is the activation signal OK to be valid.
After transmitting t-t, as shown in period 0 in FIG. 4, the communication device CEs adds the destination address and self-address codes and sends a response request signal C8D. In response to this, the interlayer & CED closes the switch 5WDt - the transmitting end S@, and enters the state shown in Figure 3 (■), and during the period shown in Figure 4 (as shown in 9, the communication device CED transmits the confirmation signal CUD). After receiving all of the confirmation signals, the communication device CEa transmits the data signal DTBt-1, and the communication device CEo starts transmitting the response signal ASD in response to receiving the data signal DTn.

Therefore, data communication is performed between Tsushin fl(J:m and (JEo), and upon completion of this, each of the above operations is repeated, and each communication device CE8 to
In the CEo, since data is transmitted sequentially starting from high priority data, there is no delay in transmitting important data.

MA, takeover signal cp, request signal CTA (II), C
In GLS such as Ts (I), since each friend communication device that transmits all the data receives all of its own transmissions and sends a Nu, and in response, sends an activation signal OK, if the transmission line L+
- If a faulty sound occurs in any part of L4, it will not be possible to confirm its own reception and will not send the activation signal OK, and the communication device after the fault will not receive all GLS signals. Only previous communication equipment is GLS
This prevents the system from entering a responsive state due to the reception of this information.

Note that each of these signals CP is used as GLS.

CT fl, time, alarm, shared data, etc. are handled in the same way, and all data is sent to the next GLS! After receiving it, an enabling signal OK is sent, and then each communication device & frame, in response to the reception of GLS, it is temporarily stored in the buffer memory and waits, and an enabling signal OK is sent, and then received. Each communication device that has
Upon reception of L, it is temporarily stored in the memory and stands by, and upon reception of the enable signal OK, the contents of the buffer memory are read out and decoded, and all subsequent operations are performed accordingly. .

Therefore, the reception status of GLS is as follows.
The decision is made only by the Natsutomo communication device, and it is only necessary to send the validation signal OK, which simplifies the communication procedure and improves the overall communication speed.

Figure 1 shows terminal equipment T in communication device CEA = CEo.
Referring to the flowchart showing the judgment and operation status of E, a processor such as a microprocessor and a memo IJr (-F) are installed in the terminal equipment TE.

That is, from the 1 initialization 101K, it is determined whether the primary g41 which each communication device CE^~CED has the transmission Qi right becomes the secondary side which does not have the transmission right, and depending on the result of this, the '1 Next side? Step 101 is performed after the power is turned on and when the power supply recovers from a power outage.
A monitoring time is set for each Eo according to its address number, and if no signal is received during this period, 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 is Y (YES), the switch 5Wt
- Control 1 transmission mode setting" 111 k, then perform takeover signal Hayabusa CP transmission" 112 i, check whether this is received via all transmission paths or not CP reception during all signals? '
113, and this is N (NO) and a certain period of time %TR has elapsed according to the timer in the processor? '114
is N, repeat steps 113 and after, and if step 114 becomes Y due to time-up of the timer,
Until the maximum number of retransmissions M set by the counter in the processor is reached, ◆Number of retransmissions = M? 115ONt-, steps 112 and subsequent steps are repeated, and when step 115 becomes Y, the process moves to alarm abnormality processing #116, where all alarms are sent out and displayed.

If step 113 becomes Y while step 115 is N, the validation signal 'OK' is sent '121 t', and the open signal 'OK' is checked to see if this is received via all transmission paths.
Reception? “122 Eri is monitored, and while C is N, a certain period of time is passed as in step 114 and 115 ◆ Ti elapsed?” 123 Y response 1 transmission count = M? ” Repeat step 121 and subsequent steps through Nt of 124, and step 1
Since 24 becomes Y, the process moves to step 116.

If step 122 becomes Y while step 124 is N, select the one with the highest priority among the transmission data it owns, add a code indicating this priority, and send the next request signal by one self-CT. ``Send 19 to 131 and check if it is received through all transmission channels or not - CT reception?''
132, and while this is N, step 114
,115 Same as %TI elapsed for a certain period of time? ”133
Number of transmissions per Y and L = Mν134. After repeating steps 131 through N', the process moves to step 116 in response to Y in step 134.

If step 132 becomes Y while step 134 is N, check whether or not this is a message sent by the user using the i-self CT? '1
35, and depending on the Y of this, it is valid 1. Hi signal'
OK send "141t", snap 122-124
Similarly, while the open signal 'OK reception 7'' 142 is N, the constant time 'Tλ elapsed 7'' 143 is Y and the number of 1 transmission = M? '144ONt- After step 141 and subsequent steps are repeated, and step 144 becomes Y, the process moves to step 116.

If step 142 becomes Y while step 144 is N, new transmission data is generated and if fc, the priority of this is sent to step 31 and checked to see if it is higher than the priority. Therefore, 1 Occurrence Priority> Sent Priority 7
``151, and for the purpose of continuously transmitting data with the same priority, Eri, 1 and other methods are used to compare the highest priority among other data to be transmitted and the priority transmitted in step 131. Highest priority = transmission source priority 7 "152 is determined, and if step 152 is N, step 1
Step 12 and subsequent steps are repeated to give other communication devices an opportunity to acquire the transmission right, while in response to Y in step 151, steps 131 and subsequent steps are repeated to give other communication devices the opportunity to receive transmission data with a higher priority than the previous one. Notify the communication device.

When step 151 is N1 and step 152 is Y,
1 data transmission process “153t-perform, step 151
Thereafter, the process is repeated repeatedly, and until step 134 becomes N, all of the own transmission data is transmitted in order from the one with the highest priority, but when a request signal CT with a higher priority is transmitted from another communication company &, step 134 is repeated. When 135 becomes N, a transition is made to a reception mode which will be described later.

Regarding the above, when step 102 is N, the switch 5W
t-control! After setting the reception mode "161t-", check the self for 1 transmission data "9?" 162K,
If this is Yf6, perform the same C transmission mode setting "163" as in step l11, and in response to the request signal 'CT reception?' 171 from another communication device t becoming Y, priority is given to the self and the next one. Self-priority (reception priority 7″1)
72 and step 9, and if this is N, it is determined that its own transmission priority is not equal to or lower than that of other transmission destinations, and that it has the transmission right 69, and the process moves to step 131.

If Step 172 is Y''t6, the terminal determines that it does not have the right to transmit, and sends the request signal CT'k GLS received by Stella 7'171 to the memory buffer area (hereinafter referred to as BFM) -BFM-CT''. 181, and then send the BFM contents t-"to the reception CT transfer N182 as is, and set 1 reception mode as in step 161" 183t-Perform, 1 data reception processing" 1
84 'i' is performed, and steps 162 and subsequent steps are repeated.

FIG. 5 is a flowchart showing the details of step 153. Is the transmission data GLS? “201t is judged, and if it is N, only 1 data transmission’202 is performed, but if step 201 is Y” GLS transmission 52
11 'i line.In addition, whether or not this is received via all transmission paths is monitored by t-' transmission (&rGLS reception?'212. While this is N, steps 114 and 11
Like 5, does STi elapse for a certain period of time? "Y in 213 and 1 number of transmissions = M?" Nt in 214 - step 21
1 and subsequent steps are repeated, and when step 214 becomes Y, the entire 1 abnormality process 215 is performed in the same way as the stick 116.

If step 212 becomes Y while step 214 is N, then steps 121 to 124 and 4, the enable signal '
OK send '221. And, is the same signal OK received? '
Has 1TR passed for a certain period of time via N of 222? Judgment of '223, number of messages sent corresponding to Y of this = M? “224 Nt.
- In all the iterations after step 221, if step 224 becomes Y, the process moves to step 215, while if step 224 is able to receive the OK signal while N, step 222 becomes Y.

The sixth factor is the flowchart that shows the details of step 184. Is the received data GLS? ” 301t, and if this is N″″c, perform 'BFM←clear' 302 for GLS, and then address it to oneself based on the address code? ``303t--Check, and depending on Y, perform deaf content decoding'' 304i, and repeat step 301 and subsequent steps.

Further, when step 301 is Y, the content is determined to be the validation signal nor<:r ``311'', and if the result is NrQn, ``BFFvi = GLS'' 312
GLS t- is stored in L9BFM, and steps 301 and subsequent steps are repeated, and then Y t of step 301 is stored.
- Interchange L-'C' step 311 becomes Y, check 'BFM contents 9?' 321 and set this to Y - Read BFM contents' 322 f, this is the takeover signal 'CP ?" 323 ', and if N, the process goes to step 304 (line s-r).

Then, the GLS containing the request signal CT t- will be reliably received and read by each communication device other than itself, and will be validated by the independent judgment of the communication device that has become the primary side. After the OK signal is sent, the communication procedure is simplified and the overall communication speed is increased.

By handling the GLS, the transmission and reception of the takeover signal CP and the request signal CT, the reception and response of each communication device are ensured, and there is no confusion in the handover of transmission rights.

Note that the response signal As, the end signal CD, the confirmation signal CU, the response request signal C8, etc. are performed during the general procedure of data transmission and reception.

72'y, and the priority may be determined by adding all the codes indicating the importance level to each transmitted data, and the priority level is 72'y.
), In addition to (II), it may be determined according to the conditions, and when all communication devices other than the communication device having the transmission right are specified at the same time by the destination address of the data signal DT,
Each designated communication device may maintain a receiving mode.

In addition, in the 2N, the switching device SW may be used as a purple source switch, and each converter 0/E, E10' may be provided in the communication device CE, and each transmission path LR, Ls may be connected to an electric signal t-. For example, the present invention can be freely modified in various ways, such as omitting the converters 0/E and E10t and just using a general switch all around the switch y.

[Effects of the Invention] As is clear from the above explanation, if the present invention is implemented, the overall communication time required for data transmission will be shortened, and the signal involved in taking over the transmission right will be reduced due to a failure in the transmission path. This prevents reception by only some communication devices, making the handover of transmission rights extremely smooth, and allowing many communication devices to be connected in a loop, such as data communication between terminals of building management equipment. Significant effects can be obtained in various types of data communications.

[Brief explanation of drawings]

Figure 1 is a flowchart showing the judgment and IO operation status.
Figure 2 is a block diagram showing the configuration of each communication device, Figure 3 is an overall block diagram, Figure 4 is a diagram showing the transmission and reception status of various signals, and Figures 5 and 6 are lower-level routines of Figure 1. A flowchart showing Ruru. CE, CE^~CED... Communication device, S...
・Transmission end, R...Reception end, SW, 5WA=SWo・
...Switcher, LH...Reception side transmission line, Ls...
- Transmission side transmission line, Ll to L4...transmission line.

Claims (1)

[Claims] Connect multiple communication devices in a loop through a transmission path,
In a data transmission method in which data is transmitted in a fixed direction, a switch is provided to select a receiving side transmission path connected to a receiving end of the communication device and a transmitting end of the communication device and connect to the sending side transmission path, Comparing the own transmission priority and the received transmission priority of another, and selecting the transmission end by the switching device when the own transmission priority is not equal to or lower than the other transmission priority. Sends its own transmission right request signal,
If the own transmission right request signal is received, it is determined that there is a transmission right, and an enabling signal for validating the transmission right request signal in another communication device is transmitted, and when the own transmission right request signal is received, the communication device determines that the transmission right is available. If there is no transmission right, it is determined that there is no transmission right, and the receiving side transmission path is selected by the switching device in response to reception of an enabling signal from another party.