JPS58111540A - Loop communication system - Google Patents

Abstract

PURPOSE:To improve the efficiency in a loop communication system and the response time, by transmitting data of the secondary station requiring the data transmission to the primary station at the same time while the primary station transmits the data to the secondary station. CONSTITUTION:In case of relay function, data coming from a line 33 is transmitted to a line 24 via an AND circuit 11, an OR circuit 12 and a driver 13 with a delay by 1 bit at a one-bit buffer 9 through a receiver 8 of a relay section 5. Further, in transmitting data, a frame transmission controlling circuit 22 of a transmission controlling section 7 gives an on-signal to an AND circuit 21 to obtain the right of transmission. When a GP (general polling) is given to a GP detection circuit 20 of the section 7 from the buffer 9, the circuit 20 operates a relay controlling circuit 14 via an OR circuit 15 of a reception control section 6 to transmits the on-signal to an AND circuit 21 and interrupts the relay function with the AND circuit 11 of the section 5. At the end of transmission of the data, a frame transmission circuit 22 resets the circuit 14 of the section 5 and is restored to the relay function.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical details of the invention The present invention provides a system in which one primary station and a plurality of secondary stations are connected in a loop on the same line. This study deals with overconfidence methods in data overconfidence systems that transmit data between

(2) Background of the technology In a data communication system in which one primary station and multiple secondary stations are connected in a loop on the same AM, data is transmitted between the primary station and one secondary station. In this case, the remaining secondary stations are simply operating a data relay function. Therefore, data overconfidence systems using the loop communication method are inefficient, and countermeasures are desired.

(3) Conventional technology and problems The loop communication system of the conventional technology transmits data from the primary station to the secondary station, sends out general polling (hereinafter abbreviated as GP), and has the aim of data transmission. The secondary stations can transmit data in turn. FIG. 1 is a diagram for explaining the loop communication method, and FIG. 2 is a time chart for explaining the operation of FIG. 1. B, (!, D, B,
F is a secondary station. Stations A to F are connected in a series loop by the same aS indicated by 1. In FIG. 2, the primary station sends data a to one of the secondary stations B-F, for example, station B, and after sending data a, sends GP.

Assuming that the data flow is in the direction of the arrow, the B station having the incoming data transmission request obtains the transmission right and sends the data b, and when the GP is completed, the B station sends out the 11GP.

0 stations are sending out days! If there is no GP, station D, which has a request for the next data transmission, completes sending out the data at IIL, which sends out the GP. 1. If there is no data to be sent to ν, dGP is relayed as is and it returns to the primary station. In this method, only the data of K12 always exists in the loop IK. In other words, the data sent from the primary station
is received at secondary station B, but is relayed at station B with a delay of 1 bit and sent to station 0. Station 0 interrupts the data a with a delay of 1 bit and sends it to station D. In this way, the bits are returned to the primary station with a delay equal to the number of sent data and the number of secondary stations. Data b sent by secondary station B is also relayed with one bit missing at station 0 and sent to station D.

In this way, each station reaches the primary station with a delay of one bit. Therefore, the loop overconfidence method of this method has the drawback of being inefficient.

(4) Purpose of sending data The purpose of the present invention is to eliminate the above-mentioned drawbacks by making it possible for other secondary stations that have data transmission requests to simultaneously transmit data to the primary station while the primary station is transmitting data to the secondary station. to enable loop times
The objective is to improve the efficiency of the loop communication system by reducing the time required for data transmission by the secondary station and improving the response time.

(5) Structure of the Invention The present invention will be explained in detail with reference to FIGS. 3, 4, and 5. Figure 3 is a diagram explaining the loose communication system of the present invention.
FIG. 5 is a time chart explaining the operation of FIG. 3. In FIG. 3, when data is being transmitted from primary station A to secondary station C as shown by arrow 2, secondary station B requires a relay function, but the secondary station, lli,? The relay function is not essential. Therefore, at this time, the secondary station, IC, IF
If there is data to be sent to the primary station A, the data can be sent at the same time. When the secondary station C starts receiving data from the primary station A, it determines whether the data is addressed to itself, and if it is addressed to itself, it inputs the armpit data and at the same time stops relaying the data.

Send GP instead. If the HDLO procedure is used, it can be determined whether the destination is the local station or not by receiving 2 bytes of flag and address. #I In Figures 3, 4, and 5, arrow 2 indicates data a to be transmitted from station 5 to station 90, and arrow 4 indicates station 0.
'/I-Gp.

If the current station has data addressed to Muma, the D station sends the data d shown by the p arrow 3 through the ap from the 0 station. Also, the 0 station sends ay and sets the continuous flag after 9 for example d-O-・1--1
--1--1-・1・-1-#0- are sent until the reception of the data from the mu station is completed, and when the reception is completed, the original middle S function is returned. When the data transmission to the A station is completed, the D station also returns to the original relay function. No. 41111 shows a case where data a sent from station P is longer than data d sent from station D. In this case, the station has completed transmission and is busy.
Although the I/A function returns, since the continuous flag is sent aS from the 0th station, the flag continues after the sending data d of the 9th station, and the loop line is prevented from becoming blank. In addition, since it is transmitted from the secondary station and relayed sequentially by the 90'PaB station, the secondary station, which has the transmission data, can thereby obtain the transmission right and transmit the data. FIG. 5 shows a case where the transmission data a of the station M is shorter than the transmission data d of the station D. In this case, since the 0 station returns to the medium function first, the GP of the A station disappears at the D station, but the 7:7 signal sent at the end of the transmission data d of the D station and the continuous "1" due to the subsequent relay function When the GP is sent out, the GP becomes the same as if the transmission was overflowing.Furthermore, when the B station transmits the GP of the A station, the data is lost at the D station, but the recovery means are the same as in the prior art.

(6) Embodiment of the Invention FIG. 6 is a block diagram of a circuit showing an embodiment of the invention. In the case of the relay function, data from the circuit 1123 passes through the receiver 8 of the relay section 5, is delayed by 1 bit by the 1-bit buffer 9, passes through the AND circuit 110R circuit 12, enters the driver 13, and is sent to the input terminal 11m1124. When receiving data from the primary station, the relay unit 501 bit buffer 9
Based on the 2-byte data of the flag and address entered into the flag and address match determination circuit 16 of the reception control unit 6, it is determined whether or not it is addressed to the own station. If it is determined that the address is addressed to the own station, oR1r! The relay control circuit 14 is activated via the circuit 15 to turn on the output, turn off the output of the NOT circuit 10 of the relay section 5, and turn off the AND circuit 1 to block subsequent data. AND 1 bit buffer 9 and reception control section 6
The data entered in l 8 is sent to the circuit 1 that determines the flag address.
Since the output of 6 is O/, the frame reception control path 19 is inputted. Further, the GP flag generation path 7 is also connected to O of the rounding relay section 5 when the flag address match determination circuit 16 is on.
The driver 13K()P and continuous 72 signals are sent to the transmission circuit 1i24 via the R circuit 12. When the reception of the data is completed, the 7-frame reception control circuit 19 of the reception control s6 is activated! The control circuit 14 is reset, the output of the NOT circuit 10 of the relay s5 is turned on, the AND circuit 11 is turned on, and the relay function is returned to.

When transmitting data, the frame transmission control circuit 22 of the transmission control section 7 sends an on signal to the rounding AND circuit 21 that obtains the transmission right. Relay part 501 bit buffer 9, 6Gp
enters the GP detection circuit 20 of the transmission control section 7, ep detection -
In order to send an ON signal to the AND circuit 21, the relay control circuit 14 is activated via the OR circuit 15 of the reception control section 6, and the relay function of the relay section 5 is cut off in the same manner as described above. The frame transmission control circuit 22 of the transmission control section 7 sends data to the driver 13 to the transmission line 24 through the OR circuit 12t"k of the relay section 5. When the data transmission is completed, the frame transmission control circuit 22 transmits the data to the reception control section 6. The relay control circuit 14 is reset and returns to the relay function as described above.

(7) Detailed explanation of the invention The present invention enables the secondary station to send data to the primary station during the loop communication system when the primary station is sending data to the secondary station. Therefore, it is possible to increase the efficiency of the loop communication method and improve response time.

[Brief explanation of the drawing]

Figure 1s1 is a diagram explaining the loop communication method, and Figure 2 is the first diagram.
It is a time chart explaining the operation|movement of a figure. - It is. FIG. 6 is a block diagram of a circuit showing one embodiment of the present invention. 5 is a relay section, 6 is a reception control section, 7 is a transmission control section, and 14 is a relay control circuit. 16 is a flag address match determination circuit, 1 x7aep flag generation circuit, and 19 is a HIRO frame reception control circuit. 20 is a GP detection path, and 22 is a frame transmission control circuit. Akira 11!1 Taku Zl! 1 Man 3 figure

Claims (1)

[Claims] In a data communication system in which one primary station and multiple secondary stations are connected in a loop on the same line and the primary station and secondary stations communicate, Wrinkle 2 due to overconfidence between stations
A loop overconfidence system characterized by providing a means by which a secondary station other than the next station can communicate with the primary station.