JPS6384333A - Circuit adaptor device - Google Patents

Abstract

PURPOSE:To improve the transfer efficiency of a circuit adaptor device by storing the address of a slave station side device that answered the polling or selecting operation carried out by the master station side. CONSTITUTION:A polling or selecting text received from a master station is sent to a control circuit 24 of a control part 15 via a receiving part 11 of a circuit adaptor. The terminal address of the text is latched by a register 21 and compared with the contents of a register 23 by a comparator 22. If noncoincidence is obtained from said comparison, the received text is sent to a terminal equipment via a transmitting part 12. When an answer text is confirmed via a receiving part 13, a transmission request signal RS is turned on and the terminal address stored in the register 21 is registered to the register 23. If the received terminal address stored in the register 21 is coincident with a registered address, the received text is sent to a terminal in a 2nd and following transmission modes.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention is directed to a data transmission system based on a polling/selecting method, in which a control device on a master station side and a plurality of terminal devices on a slave station communicate with each other. The present invention relates to a line adapter device interposed between the lines.

(Prior Art) In a polling/selecting data transmission system, a line adapter device is used to interface lines that have the same logical communication means but different electrical interfaces and communication speeds. This line adapter device connects a terminal device connected via a high-speed communication line within the premises to a regionally remote location,
This is used when connecting via a specified communication line, etc.
The logical communication means at this time is the same as the procedure for the Yokonai communication line in order to reduce the functional burden on the line adapter device.

Here, the operation of the conventional line adapter device will be explained using the system configuration example shown in FIG.

In Figure 4, 1 is the computer main body of the main station, 2.2.
. . is a modem (modulator/demodulator), 3 is a 4W (4-wire) unidirectional branch specific communication line, 4a and 41) are respective line adapter devices, and 51 to 54 are slave station terminal devices, respectively.

A polling/selecting procedure is used from the master station to the slave station, and the computer main unit l and the terminal device 51 (i-1, 2,
3, 4).

When a polling or selecting text is sent from the computer main body 1 on the master station side to the terminal device 51 on the slave side, the line adapter devices fi 4a, 4b receive the text and send the text to the respective terminal devices 51 to 54. Send. Only one terminal device (for example, 5+) responds to this text (for one polling or selection), and the response text from the same terminal device 51 is received by the line adapter*4a. .

When the line adapter device 4a receives the response text from the terminal device N5+, it sends a carrier transmission request signal (R
3) Turn on and send clear signal (CS) from the same modem 2.
After turning on, the response text is sent to the main station.

Further, after the transmission is completed, the line adapter device 4a turns off the carrier transmission request signal (R5).

After that, when a polling or selecting text is sent from the main station to the next terminal device (for example, 52),
The text is received and transmitted to each terminal device 51 to 54, and the operation described in 1 is repeated.

FIG. 5 is a time chart showing this series of operations.

Figure (a) shows the text sent from the main station, Figure (b) shows the response text from the line adapter device (4a or 4b),
The same figure (C) is the transmission text from the line adapter device (4a or 4b) to the terminal device (51), the same figure (d) is the response text from the terminal device (51) to the line adapter device (4a or 4b), The figure (e) shows the transmission request signal (R3) from the line adapter device (4a or 4b) to the modem 2, and the figure (f) shows the transmission request signal (R3) from the line adapter device (4a or 4b) from the modem 2 to the line adapter device (4a or 4b).
) can be sent (No. A (CS). Here, the text in Figures (C) and (d) is short because the line adapter device 4a
, 41) to the terminal devices 51 to 54 or a high-speed communication line.

Such line control has the following problems.

That is, there is a waiting time (T) between when the line adapter device (4a or 4b) sends the transmission request signal (R8) and when the send clear signal (CS) is sent back to the line adapter device (4a or 4b). , this waiting time (T) impedes line efficiency. This waiting time (T) varies depending on the performance of the modem, etc., but depending on the line speed, it appears as a considerably large drop in transfer efficiency.

(Problems to be Solved by the Invention) As mentioned above, in the past, the waiting time (from when the transmission request signal (R5) is sent from the line adapter device until the transmission clear signal (CS) is returned to the same device ( T), which resulted in a decrease in transfer efficiency.

An object of the present invention is to provide a line adapter device that significantly reduces the waiting time (T) described in (-) without requiring the addition of large-scale functions, and significantly improves transfer efficiency. shall be.

[Structure of the Invention (Means and Effects for Solving Problems)] The present invention stores the address of the slave terminal device that has responded to polling or selection from the master terminal device, and
When a text is sent to a terminal device having the same address, the text is sent to the terminal device and, at the same time, a signal (R8) is sent to the main station side device to prompt the device to prepare for transmission.

In this way, for subsequent text transmission to the terminal device having the address stored during polling or selection text transmission, the main station side device can prepare for transmission without waiting for a response text from the terminal device. By adopting a configuration that sends a prompting transmission request signal (R8), unnecessary time is saved between when the transmission request signal (R3) is sent from the line adapter device and when the transmission ready signal (C8) is returned to the same device E<. Waiting time (T) can be significantly reduced, and data transfer efficiency can be greatly improved.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 12 is a block diagram showing one embodiment of the present invention.

In FIG. 1, reference numeral 11 denotes a receiving unit (R) that receives text transmitted from a control device serving as a main station via a modem.
, 12 is a transmitter (T) that transmits text to a terminal device that becomes a slave station, 13 is a receiver (R) that receives a response text from the terminal device, and 14 is a transmitter that transmits a response text to a control device (main station). This is a transmitter (T).

15 is an adapter control section that controls transmission and reception within the adapter.

2.about.24 are internal components of the adapter control section 15, respectively, and 21.23 is a first..21.24 which stores a terminal address, respectively. Second address register (ADRI
, ADH2), 22 are this address register 21.
This is a comparator (COM) that compares 23 addresses. 2
4 is each address register 21, 23 and comparator 2.
2, and is in charge of transmission/reception control including terminal address registration control and transmission request signal (R8) output control as shown in FIG. When the addresses match in the address comparison, the transmission request signal (RS) is turned on, and when the addresses do not match, the terminal address stored in the first address register 21 is held in the second address register 23. It has a control function of clearing the first address register 21 and transmitting the received text to the terminal device via the transmitter 12.

FIG. 2 is a flowchart showing the transmission/reception control processing flow of the adapter control section 15.

FIGS. 3(a) to 3(f) are time charts for explaining the operation of the embodiment shown in -, respectively.

Here, the operation of one embodiment will be explained with reference to the above-mentioned FIGS. 1 to 3.

When the polling or selecting text transmitted from the control device (main station) is received by the receiving section 11 of the line adapter device, the control circuit 24 of the adapter control section 15,
The terminal address of the text is latched in the first address register 21, and the same address is compared with the contents of the second address register 23 by the comparator 22 (steps SL and S2 in FIG. 2).

At this time, if this is the first polling or selecting text transmission to the terminal device with the specified terminal address in 1., of course the terminal addresses do not match in the above comparison, and this In this case, the received text is transmitted to the terminal device via the transmitter 12, and then the receiver 13 confirms that the response text from the terminal device has been received, turns on the transmission request signal (R5), and then The terminal address latched in the first address register 21 is registered in the second address register 23 and the first address register 21 is cleared (step S3 in FIG.
S5).

Then, it waits for the transmission ready signal (C8) from the modem to become "ON", and when the signal (C8) becomes "ON2", the above response text is sent to the control device (main unit) via the modem via the transmitter 14. station), send a transmission request signal (RS) to
OFF" (steps 56 to S9 in FIG. 2).

In addition, in the above comparison and verification of terminal addresses, the terminal address has already been registered in the second address register 23, and the first
When the receiving terminal address stored in the address register 21 matches the registered address (i.e., when sending text to the same terminal device for the second time or later), the transmission request signal (
R8) is turned on and the received text is sent to the terminal device (steps S10 and S11 in FIG. 2). After that, when a response text is received from the terminal device, the response text is sent to the control device (main station) via the transmitter 14 via the modem after waiting for the transmission itJ signal (CS) from the modem to turn "on". After sending, send request signal (RS)
(Steps SI2.SO to S9 in Figure 2)
).

Figure 3 (a) shows the timing of the text sent from the control device (main station) at this time, and Figure 3 (C) shows the timing of the text sent from the line adapter device to the terminal device. The timing of the response text to the adapter device is shown in the same figure (d), the timing of the response text from the line adapter device to the modem is shown in the same figure (b), and the "on" timing of the transmitter request signal (R8) is shown. Same figure (
The “on” timing of the transmittable signal (C8) is shown in (f) of the same figure.

In this way, in response to the second and subsequent text transmissions to the terminal device with the address stored during polling or selection text transmission, the control device (main station) can be sent to the control device (main station) without waiting for a response text from the terminal device. By configuring the system to issue a transmission request to prompt transmission preparation (R8-“on”),
It is possible to significantly reduce the wasteful waiting time (T) from when the transmission request signal (R8) is sent from the line adapter device to when the send clear signal (CS) is returned to the same device.

For this reason, in the past, when comparing point-to-point and multi-drop connections, there was a significant difference in transfer efficiency; however, by adopting the configuration of the present invention described in It is possible to bring the transfer efficiency close to the same level as that of , and it is possible to significantly improve the data transfer efficiency.

[Effects of the Invention] As detailed above, according to the present invention, in the line adapter device interposed between the control device on the master station side and the plurality of terminal devices on the slave side, the terminal address storage means and , address comparison means for comparing the address stored in the terminal address storage means and the specified terminal address at the time of text transmission from the control device; and when the addresses do not match in the address comparison means, the specified terminal address is -1-
and means for storing the text in the terminal address storage means and, when the addresses match, transmitting the same text to the corresponding terminal device and at the same time transmitting a signal prompting the control device to prepare for transmission. 2 times 1 to the terminal device with the address stored at the time of transmission
In response to subsequent text transmissions, the system sends a signal prompting the main station device to prepare for transmission X and fi before waiting for a response text from the terminal device, which eliminates the need for large-scale addition of functionality. It is possible to greatly reduce the unnecessary waiting time from the time when the line adapter device sends a signal prompting for preparation until the sending permission signal is sent back to the same device, thereby greatly improving data transfer efficiency. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a flowchart for explaining the operation of the embodiment described in -1-, and FIGS. , 4th
The figure is a block diagram showing a data transmission system to which the present invention is applied, and FIGS. 5(a) to 5(f) are time charts for explaining the operation of a conventional line adapter device. 11, 13... Receiving section (R), 12.14... Transmitting section (T), 15... Adapter control section, 21.23.
・Address register (ADRI, ADR2), 2
2... Comparator (COM), 24... Control circuit (CN
T), R8...Transmission request signal, CS...Send permission signal.

Claims (1)

[Claims] In a line adapter device interposed between a control device on the master station side and a plurality of terminal devices on the slave side side, a terminal address storage means and an address stored in the terminal address storage means and a plurality of terminal devices on the slave side are provided. Address comparison means compares the specified terminal address at the time of text transmission, and when the addresses do not match, the specified terminal address is stored in the terminal address storage means, and when the addresses match, the same text A line adapter device comprising means for transmitting a signal to a corresponding terminal device and at the same time transmitting a signal prompting the control device to prepare for transmission.