CN85101327B - Data collecting apparatus of multi-point connection type - Google Patents

Abstract

The present invention relates to a data acquisition unit in a multipoint connection mode. A master station and a plurality of slave stations are connected in the multipoint connection mode; a carrier wave in an upstream transmission line between the master station and the slave stations is demodulated and secondarily modulated by each slave station and is always switched on. Modulating devices and demodulating devices are modems according to a CCITTV28 standard, each of the modems is connected with the corresponding slave station through a signal wire, and the signal wire is a signal wire of an EIARS232C standard.

Description

Data collecting apparatus of multi-point connection type

The present invention relates to a kind of data collecting apparatus of multi-point connection type, comprise a main website, it links to each other with a plurality of slave stations by two unidirectional transmission lines.More particularly, be a kind of data acquisition unit that transmits response data by slave station to main website at a high speed.

For example, in No. the 107487/77th, the disclosed patent application of Japan, introduced a kind of data acquisition unit, comprise that a main website is connected with slave station with the multiple spot type of attachment, the title of this application is " the multiple spot 1VS.N type data acquisition unit that is used for remote supervisory control system ".Main website is a plurality of slave stations of accessing one by one, and collect response data from slave station.The visit slave station is also obtained the access cycle of the required minimum time T(slave station of response data) provide by following formula:

T＝t ₁+t ₂+t ₃+t ₄

Wherein, t ₁It is required slave station call time of master access slave station;

t ₂Be that the control time is connected in transmission, connect (ON) from the carrier wave of modulating device and carry out the transmission control command and begin to carry out the data transmission to slave station;

t ₃It is the response data delivery time of slave station;

t ₄Be to transmit to cut off the control time, finish by slave station transmission data and cut off to carrier wave.

In slave station, must carry out switch control to the carrier wave of modulator, because in leading to the uplink line of main website, the data that only allow one road carrier wave to be used for a slave station transmit.

Here it is, when not carrying out the switch control of carrier wave, is used for the carrier wave that a plurality of slave station data transmit, and mixes mutually in the uplink line, and therefore, main website can not correctly demodulate the response data corresponding to the slave station of master access.Now, suppose to use the modulator-demodulator of 4800BPS, transmitting the required time of 1 bit data is 208 μ s.Because according to the suggestion of CCITT (CCITT), control time t is connected in transmission above-mentioned ₂Should be 708ms, so in prior art, also do not relate to high speed access to each slave station.Specifically for instance, when using the modulator-demodulator of 4800BPS, above-mentioned time t ₁, t ₂, t ₃And t ₄Be respectively: t ₁=12ms, t ₂=708ms, t ₃=63ms, t ₄=2ms.Therefore, by the calling of slave station is 787ms to receiving from the required time T of the response data of slave station (after this be called slave station access cycle).

One of purpose of the present invention is, a kind of data collecting apparatus of multi-point connection type is provided, and in this device, need not carry out the switch of carrier wave and control in the slave station data transfer time, thereby shorten slave station access cycle.One of feature of this invention is, main website is connected with the multiple spot type of attachment with slave station, and the carrier wave between main website and the slave station in the uplink line by demodulation and modulation once more, is kept carrier wave and continued to be in on-state in each slave station, to remove the switch control of carrier wave.From following detailed description to embodiment and accompanying drawing, can find out other purpose of the present invention and feature more significantly, wherein:

Fig. 1 is the theory diagram of one embodiment of the invention;

Fig. 2 is an illustration of expression transformat;

Fig. 3 transmits sequential chart according to data of the present invention;

Fig. 4 is the illustration that is used for modulation-demodulation device of the present invention (MODEM);

It is of the present invention from station arrangement 2-1 and serial I/O unit 100-1(SI/O unit 100-1 that Fig. 5 represents to be used for) between annexation;

Fig. 6 is a circuit diagram, is illustrated in the plug-in unit SFA800(1 among the serial I/O unit 100-1 of Fig. 5) 110 inside built-up circuit, this plug-in unit is used to connect modulation-demodulation device;

Fig. 7 is a circuit diagram, is illustrated in the plug-in unit SFA800(2 among the serial I/O unit 100-1 of Fig. 5) 120 inside built-up circuit, this plug-in unit is used to connect modulation-demodulation device;

Fig. 8 is a circuit diagram, the plug-in unit 800(3 of the essential part BASIC UNIT of slave station 2-1 in the presentation graphs 5) 130 inside built-up circuit, this plug-in unit is used to connect modulation-demodulation device.

Among Fig. 1, main website 1 is connected on the downlink transfer line 9 by modulating device 3.Data signal 7 is imported in the modulating device 3 with transmitting control signal 6, and sends into downlink transfer line 9.Downlink transfer line 9 by each splitter 5(5-1～5-N), is connected on the demodulator 4(4-1A of each slave station 2(2-1～2-N)～4-N).The data-signal 8(8-1 that each demodulator 4 is received～8-N) is input among each slave station 2(2-1～2-N).Because do not have other station to link to each other, so the signal on the downlink transfer line 9 without splitter, is directly imported demodulator 4-N with last slave station 2-N.

Above-mentioned composition is identical with prior art.Except that demodulator 4(4-1～4-N), the present invention gives demodulator 4-1B, 4-2B ...Signal among the uplink line 10(10-2～10-N) by the demodulator that newly provides, inserts in the modulator of relevant slave station.For example, the signal among the transmission line 10-2 is by demodulator 4-1B demodulation.Restituted signal 15-1, by or the door 17-1, enter among the modulator 3-1 of slave station 2-1, modulate again, be conveyed into uplink line 10-1 then.Data signal 7-1 is from slave station 2-1, and signal 15-1 is the output signal of demodulator 4-1B, two signals by or a door 17-1 send into modulator 3-1.Here, for simplicity, or the output of door 17-1 is represented with reference number 16-1.Main website is to slave station 2-2(2-1～2-N) visit, and response data there certainly of collecting.By input transfer control signal 6(6-1～6-N), each slave station provides carrier wave to uplink line 10(10-1～10-N) constantly, and makes modulator 3(3-1～3-N) continuous operation.When main website 1 to certain during from website access, have only this slave station that itself data signal 7(7-1～7-N) is provided.Then, be positioned at the modulated output signal of the up slave station in this station 2, by demodulator 4(4-1B, 4-2B ...) demodulation, demodulator is connected with the uplink line 10 of up slave station 2.Demodulated output signal 15(15-1 ,～...) by OR-gate 17 as the modulating input signal 16(16-1 of modulator 3(3-1～3-N)～16-N), modulate again, and send into the uplink line 10 of this slave station, as modulated output signal.The demodulator 4 of main website 1 is to this signal demodulation, and demodulated output signal is the data-signal 8 that main website 1 receives.

Slave station 2 is called out by downlink transfer line 9 by main website 1.For discerning accessed slave station, in transformat, to insert tributary address, as shown in Figure 2.Called slave station utilizes uplink line 10, and this calling is provided answer signal, and the situation when calling out with main website is the same, will insert tributary address in the transformat, so that main website can discern the slave station that provides answer signal.

In the embodiment of Fig. 1, main website is t to the call time of slave station ₁, the response data delivery time of slave station is t ₃, when main website sequential access slave station, the minimum time T of slave station access cycle is t ₁With t ₃Sum, as shown in Figure 3, like this, just can shorten dramatically access cycle.In the prior art of 4800BPS, T is 787ms, and now, as shown in Figure 3, under similarity condition, T is 77ms, because in the present invention, does not need the switch control time of carrier wave, so can be from a plurality of slave stations image data at high speed.

As shown in Figure 4, the concrete modulation-demodulation device (3-1) that the present invention is adopted in slave station, (4-1A), (4-1B), be V.26 according to CCITT, V.26bis, V.27, V.27bis, V.27ter or V.29 the modulator-demodulator of standard (MODEM), lead to the uplink line 10-1 of main website and from the downlink transfer line 9 of main website, link to each other with the SLINE input with the RLINE input of modulator-demodulator (MODEM) respectively, modulator-demodulator (MODEM) comprises modulator (3-1) and demodulator (4-1A), from the uplink line 10-2 of descending slave station, in kind with according to CCITT V.26, V.26bis, V.27, V.27bis, V.27ter or V.29 the demodulator DEM4-1B of standard links to each other.Holding wire MODEM-1 and MODEM-2 from modulator-demodulator (MODEM) and demodulator (DEM), it all is standard signal line according to international standard EIA-RS232C, as shown in Figure 5, for serial I/O unit 100-1(SI/O unit 100-1) link to each other with modulator-demodulator (MODEM), MODEM-1 is connected to the connector CN1(input of plug-in unit 110) on.MODEM-2 is by the connector CN2(input of plug-in unit 120) link to each other with modulator-demodulator (MODEM), plug-in unit 110 and the instantiation that plug-in unit 120 is connected with modulator-demodulator are seen Fig. 6 and Fig. 7 respectively, interconnect by the holding wire title shown in the right-hand member.

Plug-in unit 110 is used to connect modulator-demodulator (MODEM), plug-in unit 130 is essential part-BASIC UNIT of slave station 2-1, connector CN2(output with plug-in unit 110) and the connector CN1(input of plug-in unit 130) be connected to each other by holding wire SI/O-1, this holding wire is an EIA-RS232C standard signal line.The essential part of slave station 2-1 is made up of 130 plug-in units, line buffer SFA000 presses the holding wire title shown in Fig. 8 right-hand member and is connected with 130 plug-in units, analog input control AICESFA200, digital input controller DICESFA130, pulse input controller PCICE SFA150 and digital o controller DOCESFA300, the input/output bus with line buffer SFA000 links to each other respectively.After slave station 2-1 started working, the DR signal of modulator-demodulator was at plug-in unit 110(as shown in Figure 6) in become the ER signal, line buffer LBSFA000 sends the RS-N signal by this ER signal.Receive the RS-N signal, the modulating part 3-1 in the modulator-demodulator starts working.When only using the demodulator in the modulator-demodulator, the DR signal in the MODE-2 holding wire is by plug-in unit 120(as shown in Figure 7) send the RS-N signal.This RS-N signal and above-mentioned RS-N signal all pass through serial I/O unit 100-1(SI/O unit 100-1) in " line or " circuit.When only using demodulator, the CS-N signal replaces the RS-N signal, becomes the ER signal of modulator-demodulator.Main website by downlink transfer line 9 is to the calling-on signal of slave station #1, by demodulator 4-1A demodulation, and be input to serial I/O unit 100-1(SI/O unit 100-1) coupling part-plug-in unit 110 in, as the signal among the EIA-RS232C standard signal line MODEM-1.As shown in Figure 6, this signal is converted to Transistor-Transistor Logic level in plug-in unit 110, and is input to line buffer LBSFA000 as the RD-P signal.In line buffer, determine whether visit points to our station.If for the visit of our station, line buffer LB SFA000 sends the ER-N signal by plug-in unit 130.Consequently, by the effect of signal SI/O-1, the trigger FF of plug-in unit 120 is by zero setting.Thereby the RD-P signal in the MODEM-2 line of demodulator 4-1B is lockable.After sending the ER-N signal, provide the answer response by the SD-P signal.By holding wire SI/O-1 and MODEM-1, give uplink line 10-1 this response through modulator-demodulator 3-1.After answering end, line buffer LB SFA000 cuts off the ER-N signal.Then, the trigger FF of plug-in unit 120 shown in Figure 7 is opened once more.If not visit, because line buffer LB SFA000 does not send the ER-N signal, so the trigger FF in the plug-in unit 120 shown in Figure 7 is in running order for our station.Therefore, from the response of descending slave station by uplink line 10-2, by demodulator 4-1B demodulation.This response becomes the SDP signal among the EIA-RS232C standard signal line MODEM-2 by plug-in unit 120 shown in Figure 7.Back one signal becomes the signal among the MODEM-1, and sends into uplink line 10-1 by modulator-demodulator 3-1 through plug-in unit 110 shown in Figure 6.

Substantial portion of the present invention is not limited to above-mentioned embodiment, also is among the claim.

Claims (4)

1, a kind of data collecting apparatus of multi-point connection type, it comprises a main website and a plurality of slave station, main website links to each other with a downlink transfer line by homophony system device, each slave station links to each other with above-mentioned downlink transfer line from demodulating equipment by first, main website sends calling-on signal by the some slave stations of downlink transfer alignment, each slave station is by linking to each other with a uplink line from modulating device, above-mentioned main website transfers device to link to each other with above-mentioned uplink line by principal solution, the slave station that receives the master access signal then sends a response signal by uplink alignment main website, above-mentioned data link is characterised in that, in each slave station, be provided with second from modulating device, the uplink line of transferring device to be connected with principal solution is linked in sequence from modulating device and second from demodulating equipment, carrier wave on the uplink line is in each slave station demodulation, and then modulation, always in running order to keep carrier wave.

2, according to the data acquisition unit of claim 1, the modulating device and the demodulating equipment of wherein said main website and slave station are according to the CCITT modulator-demodulator of standard (MODEM) V.26, V.26bis, V.27, V.27bis, V.27ter or V.29.

3, according to the data acquisition unit of claim 1, wherein said from modulating device with link to each other with each slave station by a signal line from demodulating equipment, this holding wire is an EIARS 232C standard signal line.

4, according to the data acquisition unit of claim 1, wherein saidly be connected to each other by a signal line from demodulating equipment from modulating device and second, this holding wire is an EIA RS232C standard signal line.

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