JPS6295038A - Multiplex transmission equipment - Google Patents

Abstract

PURPOSE:To execute data transmission in a short time without using an address with regard to respective secondary stations, by providing the secondary station for calculating a parameter which is set from the outside, by a prescribed arithmetic expression, counting receiving data, also comparing its counted value with arithmetic value, and executing the data transmission to a primary station, when they have coincided. CONSTITUTION:A prescribed parameter is set to a secondary station 2 from the outside. As for the parameter, for instance, '1' is set to the secondary station 2, and as for secondary stations 3-6, parameters of 2-5 are set, respectively. This parameter is given to an operation holding circuit 25 and calculated by a prescribed arithmetic expression, and its value is held. A comparator 26 compares this arithmetic value and a counting value of a receiving counter 24, and when those values coincide, an enable signal is applied to a data reproducing circuit 27 and a receiving data is outputted to the outside. To the secondary station 2, a data signal transmitting circuit 23 to which a data input is provided from the outside is also connected, and by a coincidence signal of the comparator 26, the data input is sent out onto a transmission line 7.

Description

[Detailed Description of the Invention] [Field of the Invention] The present invention connects a primary station (master station) and a plurality of secondary stations (slave stations) to two stations.
This invention relates to a multiplex transmission device configured by connecting core wires in a multi-drop manner.

[Summary of the invention]

The multiplex transmission device according to the present invention includes a primary station that transmits a reset signal in advance prior to data transmission for l-scanning, and then sequentially transmits data to each secondary station, and a device that is connected to the primary station in a multi-drop manner. A secondary station that calculates externally set parameters using a predetermined calculation formula, counts the received data, compares the counted value with the calculated value, and when they match, transmits data with the primary station. A multiplex transmission device is constructed by the following. Such a configuration makes it possible to perform data transmission in a short time without using addresses for each secondary station.

[Prior art and its problems]

In general, in time-division multiplex transmission equipment that connects a primary station and multiple secondary stations using a two-core dedicated line to configure a data transmission system, a unique address is set for each secondary station. ,
Based on the address, data transmission between the primary station and the secondary station is performed. In this way, when setting a unique address for a secondary station and transmitting data using that address, it is necessary to add an address to the transmitted data, which makes it difficult to improve the efficiency of data transmission. Ta.

In particular, if the number of secondary stations is large, the address code becomes complex, and if the number of data is small, the actual data transmission time becomes short, resulting in a significant drop in transmission efficiency.

[Purpose of the invention]

The present invention has been made in view of the problems of the conventional multiplex transmission device, and it does not transmit the address of each secondary station in the transmission data, and can transmit a large number of secondary stations in a short time. An object of the present invention is to provide a multiplex transmission device capable of data transmission.

[Structure and effects of the invention]

The present invention is a multiplex transmission device in which a primary station and a plurality of secondary stations are connected in a multi-drop manner via a transmission line, and the primary station is
It has a reset signal transmitting means for transmitting a reset signal to each secondary station, and a data transmitting means for transmitting data to each secondary station at predetermined intervals starting from the highest ranking secondary station. The station has a calculation holding means that calculates externally given parameters using a predetermined calculation formula and holds the calculated value, a reception counter that counts the number of data sent on the transmission line, and a count value of the reception counter and calculation storage means. Comparing means for comparing the calculated values of and outputting a matching signal when they match, and data signal receiving means for receiving and reproducing the data signal given from the primary station when a matching signal is given from the comparing means. and 1 when a matching signal is given from the comparing means.
The present invention is characterized by comprising a data signal transmitting means for transmitting a data signal to the next station.

According to the present invention having such characteristics, predetermined parameters are externally set in each of the secondary stations, and values calculated based on the parameters are held in the calculation holding section. When transmitting data to the primary station, the data signals are counted and compared with the held value, and if they match, data is transmitted to the primary station. In this way, since no address is added to the transmitted data, the transmission time for one cycle of data transmission with each secondary station can be shortened. Particularly when the number of connected secondary stations is large and the amount of data transmitted between the secondary stations and the primary station is small, high-speed data transmission can be performed.

[Explanation of Examples]

FIG. 1 is a schematic block diagram showing an embodiment of a multiplex transmission apparatus according to the present invention. In this figure, the input/output terminal of primary station 1 is connected to a 2-core transmission line 2, and multiple 2-wire
Next stations 3 to 6 are connected in a multi-drop manner at arbitrary points. The primary station 1 sends a reset signal to each secondary station, sequentially sends a data signal to each secondary station, receives a data signal received from a transmission line 7, and performs data transmission.

(Configuration of primary station) As shown in the configuration of the primary station 1 in FIG.
1, and the transmission counter 12 is reset. The reset signal transmitting circuit 11 transmits a reset signal to each secondary station via the transmission line 7, and after transmitting the reset signal, provides a transmission start signal to the data signal transmitting circuit 13. The data signal transmitting circuit 13 sequentially transmits data to each secondary station based on data input provided from the outside, and provides a count input to the transmission counter 12 for each transmission. Further, a data signal receiving circuit 14 is connected to the transmission line 7. The data signal receiving circuit 14 receives data signals from each secondary station and provides a start signal to the comparator 15. The comparator 15 estimates the number of connected secondary stations and compares the set value with the counted value of the transmitting counter 12. If they do not match, the data signal transmitting circuit 13 A transmission continuation signal is given, and in case of failure, a 1 scanning end signal is given.

(Configuration of Secondary Station) FIG. 3 is a block diagram showing the configuration of the secondary station 2, and the other secondary stations 3 to 6 have similar configurations. Now, the secondary station 2 connects the reset signal receiving circuit 21 to the transmission line 7. A data signal receiving circuit 22 and a data signal transmitting circuit 23 are connected. The reset signal receiving circuit 21 provides a reset signal to the reception counter 24 when a reset signal is provided from the primary station 1. Further, predetermined parameters are set to the secondary station 2 from the outside. For example, the parameter is set to 1 for secondary station 2, and parameters 2 to 5 are set for secondary stations 3 to 6, respectively. This parameter is given to the calculation/holding circuit 25, where it is calculated using a predetermined calculation formula and its value is held. The comparator 2G compares this calculated value with the counted value of the receiver (δ counter 24), and if these values match, it gives an enable signal to the data reproducing circuit 27 and outputs the received data to the outside. A data signal transmitting circuit 23 to which data input is given from the outside is also connected to the secondary station 2, and a comparator 26
The data input is sent onto the transmission line 7 in response to the coincidence signal.

(Operation of this embodiment) Next, the operation of this embodiment will be explained with reference to a flowchart and time chart 1-. 4 and 5 are flowcharts showing the operations of the primary station 1 and each of the secondary stations 2 to 6, respectively, and FIG. 6 is a time chart showing the sending signals of each station during data transmission. First, when a 1 scanning start signal is given to the primary station 1 from the outside, it starts operating,
In step 31, the transmission counter 12 is reset and the reset signal R is sent out from the reset signal transmission circuit 11 as shown in FIG. 6fal. When each of the secondary stations 2 to 6 starts operating, it proceeds to step 41 and waits for a reset signal from the primary station l, and when the reset signal R is received, it resets the reception counter 24. Now, for each secondary station, a set value A (n+) is set in advance by the calculation holding circuit 25 from an external setting value, and the data is transferred to the calculation holding circuit 25.
5, and the calculation value is calculated by the following equation.

Calculated value - A(n)X 2-1 (n = 1 to 5
) This calculated value is held by the calculation holding circuit 25. Therefore, secondary stations 2 to 6 each have 1. 3. 5゜7.
This means that the calculated value of 9 is held in the holding circuit 25. Now, the primary station 1 proceeds from step 32 to step 33, and based on the data input from the data signal transmitting circuit 13, the data signal T1 to the secondary station 2, which has the highest priority, is transmitted on the transmission line 7.
Send out. Then each secondary station will perform steps 43 and 44.
The data signal is received and the reception counter 25 is incremented. Then, in step 45, it is determined whether the count value of the reception counter 24 and the calculated ργ value held in the calculation holding circuit 25 are equal. In the secondary station 2, the calculated value held in the calculation holding circuit 25 is 1, and these values are equal, and all other secondary stations 3 to 6 do not have the same value, so only the secondary station 2 performs step 46. .47, and as shown in Figure 6 (bl 4), the data signal regeneration circuit 2
7 and outputs the received data TI to the outside, and sends the data signal R1 to the primary station. On the other hand, the other secondary stations return to step 43 and wait for the next data signal.

Now, the primary station 1 receives the data signal R1 from the secondary station 2 (step 35), proceeds to step 36, and receives the data signal R1 from the counter 12.
Check whether the count value is equal to the number of secondary stations set externally. If these values are not equal, the process returns to step 33, where the data signal T2 is sent to the next secondary station 3 and the transmission counter 12 is incremented. Since the data signals Tl, R1, and T2 are sent out on the transmission line 7, the secondary station 3 counts the number of data signals using the reception counter 24, and when data T2 is sent out, the calculation is held in the secondary station 3. Since it is equal to the calculated value in the circuit 25, only the secondary station 3 goes through steps 46 and 47Q, transmits the data signal R2, and outputs the received data T2 to the outside, and the other secondary stations 2 and 4
-6 returns to step 43 and waits for the next data signal. This will result in Figure 6(a).

As shown in FC+, only the secondary station 3 can perform data transmission with the primary station 1. Thereafter, for the secondary stations 4 to 6, the number of data signals transmitted onto the transmission liner 7 is counted by the reception counter 24, and the received data signal T3 is counted only when the calculated values held there match.
~ Output T5 externally and send data signal R to primary station 1.
3, R4, and R5, respectively. In this way, data transmission can be performed between the primary station 1 and a plurality of secondary stations without setting an address for each secondary station.

In this embodiment, a multiplex transmission apparatus using five secondary stations has been described, but it goes without saying that a similar system can be constructed using an even larger number of secondary stations.

Furthermore, in this embodiment, a multiplex transmission device that alternately transmits data between each secondary station and a primary station has been described. The multiplex transmission device according to the present invention can also be used when any of these secondary stations are connected by changing the calculation formula of the calculation holding circuit that calculates the number of data sent onto the transmission line during data transmission. It is possible to apply.

[Brief explanation of drawings]

FIG. 1 is a schematic block diagram showing an embodiment of the multiplex transmission device according to the present invention, FIG. 2 is a block diagram showing the configuration of the primary station 1 of the multiplex transmission device according to the present embodiment, and FIG. 3 is the present embodiment. A block diagram showing the configuration of the secondary station, Fig. 4 is the primary station,
Figure 5 shows flowcharts 1 and 6 showing the operations of each secondary station.
The figure is a time chart showing the output of each station during normal transmission. 1-----・Primary station 2--6---Secondary station 7--
--Transmission line 11---Recession 1-Signal transmission circuit
12-----One transmission counter 13, 23--
--Data signal transmission circuit 14, 22--111 Data signal reception circuit 15, 26--Comparator 21--Reset signal reception circuit 24-
・-Reception counter 25- ・Calculation holding circuit Figure 1, Figure 2? --S Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) A multiplex transmission device in which a primary station and a plurality of secondary stations are connected in a multi-drop manner via transmission lines, and the primary station transmits a reset signal to send a reset signal to each secondary station. and data transmission means for sequentially transmitting data to each secondary station at predetermined intervals starting from the highest priority secondary station, and each of the secondary stations performs predetermined calculations on parameters given from the outside. Calculation holding means that calculates according to a formula and holds the calculated value; Comparing means that compares the counted value of the reception counter and the calculated value of the calculation holding means and outputs a match signal when they match; and the comparing means data signal receiving means for receiving and reproducing a data signal given by the primary station when a matching signal is given from the comparing means; and sending a data signal to the primary station when a matching signal is given from the comparing means. 1. A multiplex transmission device comprising: data signal transmission means for transmitting a data signal.