JPS61237552A - Multiplex transmission equipment - Google Patents

Abstract

PURPOSE:To simplify the circuit by receiving/transmitting the data between the primary station and plural number of secondary station connected each other in loop by a poling signal and a request signal, and by placing the transmission type and reception type of secondary stations mixedly. CONSTITUTION:Plural number of secondary stations 2-6 are connected in loop to a primary station 1 by a two-core transmission line 7. The primary station 1 sends a poling signal from its output terminal 1-0, and when it receives a request signal from the transmission line 7, it sends out a data signal. Also the primary station 1 sequentially receives the data signal after it sent out the poling signal. Two types of secondary stations are mixed up, the transmission type which transmits the given data signal after it received the poling signal and further sends the poling signal to lower rank stations, and the reception type which sends a request a signal after receiving the poling signal and receives the data and further sends the poling signal to lower stations. Thus, setting of address becomes unnecessary and multiplex transmission can be done by simple circuit.

Description

[Detailed Description of the Invention] [Field of the Invention] The present invention is constructed by connecting a primary station (master station) and a plurality of secondary stations (slave stations) in a digital chain manner using a dedicated two-core wire. This invention relates to a multiplex transmission device.

[Summary of the invention]

The multiplex transmission device according to the present invention receives a data signal after sending out a polling signal, and when a request signal is obtained, two
A primary station that sends out a data signal to the next station, and a sending-type secondary station that is connected to the primary station in a continuous loop in a digital chain manner and receives polling signals from the priority station and sends out data. , a transmission type secondary station that receives a polling signal from a priority station, sends a request signal, receives a data signal, and receives a polling signal to form a transmission device. This configuration eliminates the need to set addresses for individual secondary stations, and allows for transmitting and receiving secondary stations.
It becomes possible to connect a mixture of subsequent stations.

[Prior art and its problems]

In general, in multiplex transmission equipment that configures a data transmission system by connecting a primary station and multiple secondary stations with a two-core dedicated line, the secondary stations are connected to any point on the common bus. A multi-drop system is often used, and in this case it is necessary to set a unique address for each secondary station. Such address settings are normally made using a DIP switch or the like provided at each secondary station.

However, when it is necessary to make the secondary station extremely compact, there is a problem in that the DIP switch limits the miniaturization. Furthermore, when setting up a large number of secondary stations at once, setting addresses is relatively easy, but when increasing or decreasing the number of secondary stations after configuring the multiplex transmission equipment system, the addresses may not be consecutive. Furthermore, there is a possibility that a plurality of secondary stations may be mistakenly set at the same address, resulting in the problem of transmission hoovering. In addition, a shift register method is known in which addresses are not specified for each secondary station in order to facilitate work at the secondary station installation site, but in this method, in addition to data signals, signal lines for clock signals are However, there is a problem in that a transmission system cannot be constructed using inexpensive two-core cables, and the price of the transmission cable increases. - Also, the second auxiliary station has a receiving type secondary station that receives data from the primary station and drives relays, etc., and a transmitting type secondary station that is connected to sensors etc. and sends data to the primary station. However, with conventional multiplex transmission equipment, it is difficult to configure a transmission equipment by mixing these, and the primary station must memorize the connection order, which complicates the system configuration. [Objective of the Invention] The present invention has been made in view of the problems of the conventional multiplex transmission equipment, and uses Dl and P switches to set addresses for each secondary station. It is an object of the present invention to provide a multiplex transmission device that can be configured by connecting a transmitting type secondary station and a receiving type secondary station in the same loop shape and using a two-core transmission cable without the need for a transmission type secondary station and a receiving type secondary station.

[Composition and effects of all types]

The present invention is a multiplex transmission device in which a primary station and a plurality of secondary stations are loop-connected in a digital chain manner via a transmission line, and the primary station transmits a polling signal, which is the right to transmit and receive, to the secondary station having the highest priority. A polling signal transmitting means for transmitting a polling signal to a station, a request signal receiving means for receiving a request signal obtained from a transmission line, a data signal receiving means for sequentially receiving data signals obtained from the transmission line after transmitting a polling signal, and a request signal. data signal transmitting means for transmitting the data signal to the secondary station after reception; each secondary station is connected between the input and output, passing the data signal and request signal obtained from the input terminal and blocking the polling signal. a transmitting type secondary station having a filter means for transmitting a polling signal, a transmitting means for transmitting a data signal given after receiving a polling signal, and a polling signal transmitting means for transmitting a polling signal to a subsequent station after the transmitting means transmits the data signal. and a filter means connected between the input and output terminals to pass the data signal and request signal obtained from the input terminal and block the polling signal, a request signal sending means for sending out the request signal after receiving the polling signal, and a data signal after sending the request signal. A receiving type secondary station having data signal receiving means for receiving the data signal and polling signal sending means for sending out the polling signal after receiving the data signal is connected in a mixed manner.

According to the present invention having such characteristics, a polling signal, a data signal, and a request signal are transmitted using a two-core transmission line, and the transmitting type secondary station transmits its own data after receiving the polling signal. After receiving the polling signal, the reception-type secondary station sends a lift-hand strike signal onto the transmission line, receives data from the primary station based on it, and performs data transmission with the primary station. There is. After that, when the secondary station completes its operation, it issues a polling signal and sends it to the subsequent secondary station. With such a configuration, data transmission between the primary station and the transmitting type and receiving type secondary stations can be performed using two-core transmission and only vjI. The transmitting type and receiving type secondary stations can be connected to the same loop, and there is no need to detect which station is connected at the time of connection. Since addresses are not set for each secondary station, there is no need to provide a DIP switch. Therefore, each secondary station can be downsized, and workability when installing the secondary stations can be improved.

[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, primary station 1 and multiple 2
The next stations 2.3, 4.5.6 are connected in a loop in a digital chain by a two-core transmission line 7. That is, the output terminal 1-o of the primary station is connected to the input terminal 2-i of the secondary station 2 connected to the highest order, and the output terminal 2-o of the secondary station 2 is connected to the next It is connected to the input terminal 3-i of the secondary station 3. Similarly, the output terminal 3-o of the secondary station 3 is connected to the input terminal 4-i of the secondary station 4, and the output terminal 4-o is connected to the input terminal 4-i of the secondary station 5.
The output terminal 57o is connected to the input terminal 5-i of the
It is connected to the input terminal 6-i of the next station 6. The output terminal 6-o of the last secondary station 6 is connected to the input terminal 1-3 of the primary station l via a transmission line A7. The primary station 1 transmits the balling signal to the highest ranking secondary station among the secondary stations connected in a loop, receives and receives data sequentially from the transmitting secondary station, and also sends requests. It sends data to a receiving type secondary station according to the signal. Here, secondary stations 2, 3, and 5 are transmitting type secondary stations, and secondary stations 4 and 6 are receiving type secondary stations, and these transmitting and receiving type secondary stations are mixed and connected via transmission line 7 in a digital chain configuration. shall be connected to.

(Configuration of Primary Station) As shown in FIG. 2, the primary station 1 has a polling signal detection circuit 11 that operates based on an external start signal. The polling signal detection circuit 11 provides a start signal to the polling signal transmission circuit 12 at the start of operation, and provides a reset signal to the I10 flag 13, the output counter 149, the person counter 15, and the address counter 16. The polling signal detection circuit 11 detects a polling signal obtained from the input terminal 1-i of the primary station 1, and when detecting the polling signal, outputs a 1-scan completion signal to the outside.

The polling signal transmitting circuit 12 is provided with the output of an oscillator 17 that oscillates a polling signal frequency, for example, IMHz, and also sends out a polling signal from an output terminal 1-o in response to a start signal. Input terminal 1-
i has data signal reception and reproduction times Ia! 18 is connected, and receives data and signals from the secondary station obtained from input terminals 1-3 and reproduces them as data output.
It sets the flag 13 and provides counting input to the input counter 15 and address counter 16. A request signal receiving circuit 19 is further connected to the input terminal 1-i.

The request signal receiving circuit 19 receives a request signal given from a receiving type secondary station, and uses its output to
It resets the 0 flag 13 and provides a count input to the output counter 14, and also provides data transmission timing to the data signal transmission circuit 20. The data signal transmitting circuit 2o sends a data signal to the secondary station that generated the request signal via the transmission line 7 using an NRZ code or the like using a frequency sufficiently lower than the boring signal, for example, 60 KHz, and also sends the data signal to the secondary station that generated the request signal via the transmission line 7. 16 is given counting input. The address counter 16 is a counter that counts the addresses of secondary stations connected to the transmission line 7 and performing data transmission with the primary station 1, and its output is given to the display section 21. Furthermore, the r10 flag 13 is a flag that is set when the secondary station performing data transmission is a transmitting type secondary station, and is reset when it is a receiving type secondary station.
The output is given to the display section 21. The display section 21 displays transmitting/receiving type secondary stations corresponding to the addresses of the secondary stations.

(Configuration of Transmission Type Secondary Station) FIG. 3 is a block diagram showing the configuration of the transmission type secondary station 2, and the other secondary stations 3 and 5 have similar configurations. Now, a low-pass filter 31 and a polling signal detection circuit 32 are connected to the input terminal 2-i of the secondary station 2. The low-pass filter 31 is a passive filter made of LC, which blocks the IMHz frequency signal used as the boring signal regardless of the power supply state, and cuts off the IMHz frequency signal provided from the transmission line 7, for example, 60 KH.
A data signal modulated by z, a request signal to be described later, etc. are transmitted as they are to the output terminal 2-o. Further, the polling signal detection circuit 32 receives the boring signal applied via the transmission line 7, and provides the detection timing to the data signal transmission circuit 33. The data signal transmitting circuit 33 transmits data to be transmitted from the secondary station 2 to the primary station 1 onto the transmission line 7 after receiving the polling signal.
The same as the data signal transmitting circuit 20 of the next station (a signal modulated by NRZ code etc. is used. Also, the timing after transmitting the data signal is given to the boring signal transmitting circuit 34. The boring signal transmitting circuit 34 is 2 is a transmitting circuit which oscillates a bowling signal by itself, is connected to its output terminal 2-o, and then transmits a bowling signal to the secondary station in the order, and an oscillator 35 is connected to these transmitting circuits 33 and 34. And the low pass filter 31
．． The outputs of the data signal transmitting circuit 33 and the boring signal transmitting circuit 34 are transmitted to the subsequent secondary station 3 via the output terminal 2-o.
It is connected to

(Configuration of Reception Type Secondary Station) FIG. 4 is a block diagram showing the configuration of the reception type secondary station 4, and the reception type secondary station 6 also shows a similar configuration. Now, to the input terminal 4-i of the secondary station 4, a low-pass filter 41, a polling signal intelligence circuit 42, and a data signal receiving/reproducing circuit 43 are connected. The low-pass filter 41 is a filter that blocks high-frequency signals used as boring signals, similar to the above-described low-pass filter 31. The polling signal detection circuit 42 receives the boring signal and provides the detection timing to the request signal transmission circuit 44. Like the data signal, the request signal is composed of an NRZ code or the like with a frequency of 60 KHz, and is a signal requesting the primary station 1 to transmit data, and is sent from the request signal transmitting circuit 44 to the transmission line 7. The sending timing of the request signal transmitting circuit 44 is then transmitted to the data signal receiving/reproducing circuit 43. The data signal receiving/reproducing circuit 43 receives the data signal sent from the primary station 1, decodes it, and outputs it, and its output is 2
It is used as a drive signal for different output means, such as a relay, for each next station. The reception timing of the data signal reception/reproduction circuit 43 is given to the boring signal transmission circuit 45. The bowling signal transmitting circuit 45 is a transmitting circuit that, like the polling signal transmitting circuits 3 and 4 described above, oscillates a bowling signal in the secondary station 4 itself and transmits the bowling signal to the subsequent secondary station. Then, the output of the oscillator 46 is given as a transmission clock to the boring signal transmission circuit 45 and the request signal transmission circuit 44, and the data signal reception and
It is given to the reproduction circuit 43 as a reception clock.

(Operation of this embodiment) Next, the operation of this embodiment will be described with reference to flowcharts and waveform diagrams. FIG. 5 is a flowchart showing the operation of the primary station 1, and FIGS. 6(a) to 6(f) are waveform diagrams showing signal waveforms at each point of a % f shown in FIG. In this figure, when a start signal is given to the primary station 1, the polling signal detection circuit 11 operates, and the operation signal resets the I10 flag 13, the output counter 14, the input counter 15°, and the address counter 16 (step 51). ). At the same time, a start signal is given to the polling signal transmitting circuit 12, and a boring signal P1 is sent from the primary station 1 to the transmission line 7 as shown in FIG. 6(a) (step 52). And step 53゜55
, 56 connected to input terminal 1-i;
Check whether a polling signal, data signal, or request signal is received from the receiving circuit. The boring signal P1 is transmitted to the highest priority secondary station 2 connected to the output terminal 1-o of the primary station 1, and the polling signal detection circuit 3
Detected by 2.

As described above, since the boring signal is modulated with a high frequency of frequency IM)lz, it is not transmitted to the subsequent secondary stations 3 and onwards, as shown in FIGS. 6(b) to 6(f).

In the secondary station 2, the detection timing of the boring signal is transmitted to the data signal transmitting circuit 33, and the data signal D2 is sent from the secondary station 2 to the transmission line 7, as shown in FIG. This data signal D2 passes through the low-pass filter of each secondary station, is received by the data signal receiving/reproducing circuit 18 of the primary station 1, and is output. Therefore, the process proceeds from step 55 to step 57, where the I10 flag 13 is set and the input counter 15 is incremented. The playback data received at the same time is output to the outside (steps 58 and 59).
, the process proceeds to step 63, where the address counter 16 is incremented. Furthermore, as shown in FIG. 7, the display section 21 displays that the first connected secondary station 2 is a transmitting type secondary station (step 64), and the process returns to step 53 to repeat the same process. Then, the secondary station 2 transmits the timing after transmitting the data signal to the polling signal transmitting circuit 34, and transmits the boring signal P2 to the secondary station 3 in the succeeding order as shown in FIG. 6(b) to perform data transmission processing. finish.

Now, since the secondary station 3 is also a transmitting type secondary station like the secondary station 2, it receives the boring signal P2 from the secondary station 2 and sends the data D3 as shown in FIG. 6(b) and (0). The transmission line 7
Send upward. Then, the bowling signal P3
Send to next station 4. Since the secondary station 4 is a receiving type secondary station having the configuration shown in FIG. Since the request signal R4 is composed of a signal having a frequency of 60K)lz like the data signal, it passes through the low-pass filter of each secondary station and is given to the primary station 1. The primary station l receives this signal R4 by the request signal receiving circuit 19, proceeds from step 56 to step 60.61, resets the I10 flag 13, increments the output counter 14, and further transmits it to the data signal transmitting circuit 20. Communicate the timing. Then, as shown in Figure 6+8), the data signal D is transmitted from the primary station 1.
4 is sent.

The secondary station 4 receives this data signal D4 from the data signal receiving/reproducing circuit 43, reproduces it, drives a relay, etc., and transmits a reception timing signal to the polling signal transmitting circuit 45. Therefore, the boring signal P4 is sent from the secondary station 4 as shown in FIG. This shows that the receiving type secondary station is connected to the third secondary station.

Then, the process returns to step 53 and the same process is repeated. Since the secondary station 5 is a transmitting type secondary station, it sends out a data signal D5 and a military ring signal P5 after receiving the boring signal P4, as shown in FIG. 6 (el).

Further, since the secondary station 6 is a receiving type secondary station, as shown in FIG. 6(f), it sends out the request signal R6 after receiving the polling signal, and after receiving the data signal D6 from the primary station, sends out the polling signal P6. Send out. Then the bowling signal P
6 is transmitted to the primary station 1, the polling signal detection circuit outputs a signal indicating the completion of one scan (step 54).
At the same time, the process returns to step 51 to reset the I10 flag 13 and each counter 14 to 16, and the same process is repeated thereafter.

In this way, the primary station 1 receives the data signal after sending out the polling signal, and transmits the data to the secondary station in response to the request signal, thereby creating a two-core system by mixing the transmitting type and receiving type secondary stations. 2 even when connected to a transmission line.
It becomes possible to automatically identify the type of next station and perform data transmission without setting addresses 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 low-pass filter is provided in each secondary station in order to pass the data signal and request signal as they are and block only the polling signal. By modulating it, it is also possible to change the filter that blocks the polling signal to a filter such as a bypass filter.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing an embodiment of a multiplex transmission device according to the present invention, and FIG. 2 is a schematic block diagram showing an embodiment of a multiplex transmission device according to the present invention.
A block diagram showing the configuration of the next station 1, FIG. 3 is a block diagram showing the configuration of the transmitting type secondary station, FIG. 4 is a block diagram showing the configuration of the receiving type secondary station, and FIG.
6 is a flowchart showing the operation of the primary station 1, and FIG. 6 is a waveform diagram showing the waveforms of each part a to f of the transmission line of the multiplex transmission device.
FIG. 7 is a display diagram showing the types of secondary stations displayed on the display unit 21. 1--------1/1st station 2, 3.4.5.6-
・−・−・Secondary station 7−−−−−−Transmission line 11.
32. 42-----Polling signal detection circuit 12. 34. 45--------Polling signal transmission circuit 13-...-I/O flag 14.
15.16---Counter 1B, 4
3--Data signal reception/regeneration circuit 20.33--
-Data signal transmission circuit 31.41--Low pass filter 44--Request signal transmission circuit Patent applicant Tateishi Electric Co., Ltd. agent Patent attorney Yoshiki Okamoto (and one other person) Fig. 1 3 Figure 2 Figure 4 Figure 7 Figure 6 Procedural amendment (voluntary) June 17, 1985 1. Display of the incident 1985 Patent Application No. 078948 2. Name of the invention Multiplex transmission device Name (294) Tateishi Electric Co., Ltd. Representative: Takao Miki 4, Agent address: 3rd floor, 5th Shinkosan Building, 1-13-38 Nishihonmachi, Nishi-ku, Osaka-shi, Osaka 550, Details of the invention in the specification subject to amendment Explanation Column 6, Contents of Amendment (1) The description of "transmitting type secondary station" in the first line of page 4 of the specification will be corrected to "receiving type secondary station." (2) Specification No. 11 due east, line 6, page 12, line 8, 14
The description of r60KHzJ on page 1, line 1 and page 17, line 13 will be corrected to r60KHz and 30 KHz J. (3) The description of ``rNRZ code'' on line 7 due east of page 11, line 17 of page 12, and line 1 of page 14 of the specification will be corrected to ``biphase code.''that's all

Claims (2)

[Claims] (1) A multiplex transmission device in which a primary station and a plurality of secondary stations are loop-connected in a digital chain manner via a transmission line, and the primary station transmits a polling signal, which is the right to transmit and receive, to the two stations with the highest priority. a polling signal transmitting means for transmitting a polling signal to the next station; a request signal receiving means for receiving a request signal obtained from the transmission line; a data signal receiving means for sequentially receiving data signals obtained from the transmission line after transmitting the polling signal; data signal transmitting means for transmitting a data signal to the secondary station after receiving the request signal, and each of the secondary stations is connected between input and output and passes the data signal and request signal obtained from the input terminal and performs polling. Transmission comprising a filter means for blocking a signal, a transmitting means for transmitting a data signal given after receiving a polling signal, and a polling signal transmitting means for transmitting a polling signal to a subsequent ranking station after the transmitting means transmits the data signal. type secondary station, filter means connected between input and output for passing data signals and request signals obtained from input terminals and blocking polling signals, request signal sending means for sending out request signals after receiving the polling signals, and request signal sending means for sending out request signals after receiving the polling signals. a receiving type secondary station having data signal receiving means for receiving a data signal after transmitting the signal; and polling signal transmitting means for transmitting a polling signal after receiving the data signal;
A multiplex transmission device characterized by being connected in a mixed manner. (2) The polling signal sent out by the polling signal sending means of the primary station and each of the secondary stations is a data signal;
Claim 1, wherein the signal has a higher frequency than the request signal, and the filter means of each secondary station is a low-pass filter that blocks the polling signal and passes the data signal and the request signal. The multiplex transmission device described.