JPS6019340A - Control system of line concentrator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a communication system, and particularly to control suitable for an online system that uses a contention system.

[Background of the invention]

Conventional line concentrators are installed on the terminal equipment side to reduce the number of uses and keep line usage charges low, but in this case, the communication method or Volink/
The drawback was that it was limited to the selection method and could not use the contention method.

[Purpose of the invention]

An object of the present invention is to provide a line concentrator that enables a contention type communication system.

[Summary of the invention]

In order to achieve the above objectives, the key point is how to avoid the transmission section, which is the biggest problem with the contention method.

In the present invention, this method of avoidance is achieved by using three-phase clocks and giving priority to the earlier carrier detection. And when the line program number and the prioritized line number are different,
This is avoided by detecting line mismatch from the LiC and notifying the communication management blockram to switch the line blockrum number.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 7.

FIG. 1 shows a system configuration using this device (LC).

LC is a central processing unit ((:'PU) and a terminal unit (DTB).
) is located between multiple units, and line connection is made by modem (Co., Ltd.).

FIG. 2 shows the concept of a logical switch on the CPU side that houses the LC.

The LC 81 and the communication management 10 crumb 82 are switched in synchronization.

FIG. 4 shows a logical block diagram of the LC.

The logical configuration is characterized by a switch section (SW) and a modem carrier signal detection section (CD).

In the case of contention method, N, N+1. A transmission request (ENQ) occurs simultaneously in the CPU on the center side.

FIG. 3 shows a case where a quick calculation of the transmission error occurs at the center side CPU, DTEN, and N+1.

Also, we will show how to avoid this situation with this device.

In the case of this figure, the line activation occurs at DTI (N), and the line activation occurs a little later at 1JTEN+1.Also, when the line activation occurs on the CPU side, the mode of this LC changes from IDLE to N.
Transition to mode (DTEN activation detection).

After N mode, starting from DTEN+1 is the next IDLE
No reception until mode status.

The activation of CPU 111ON+1 is directly transmitted from this LC to DTb via ICA.

However, here, this LC is I) TEN startup reception and CPU
1) Since the TEs are different, a mismatch in line numbers is detected.

If a mismatch is detected, this LC reports it to the IOA. Upon receiving this report, the ICA switches the N+1 forest block on the communication management block to the N line block.

Next, detailed circuit operation will be described.

Figure 5 shows the DTBN, N+1 modem carrier signal (
When t2. Or Sunblink at t3. Based on the result of the sunblink, the logic SW is switched to either N or N+1.

Activation of the line from the CPU is performed by switching between /... and hardware signals based on the C0NT_σL signals 2 and 3 from the ICA and the kGES signal. In this case, the IOA analyzes the data sent from the communication management block and converts it into a signal.

Prior to the ENQ data, the communication management program notifies the line number in a data format that does not affect the terminal device even if it is transmitted according to the protocol.

In this embodiment, in the case of D TE N, CI ON i
' ROL2. In the case of DTEN+1, C (JNT 几waL
3°I D ], the reset signal RES is used to enter the E state. RES is generated depending on connection/disconnection data, 1) LE, and EOT data.

The switch timing is as shown in Figure 6.

tl is Ci'U activation, t2 is DT1! ! N5t3 is N+
1 startup is accepted.

tl is a timing that always occurs in the N0I (MAL state), and t2 or t3 is a timing that stops upon detection of either DTE.
As shown in the figure.

〔Effect of the invention〕

According to the present invention, since it is possible to control several devices with a single line communication adapter, an online system that conventionally required two or more lines can be connected to just one device.

[Brief explanation of drawings]

Figure 1 is a system configuration diagram, Figure 442 is a conceptual diagram of a four-value switch, the third factor is a transmission fA contest diagram, and Figure 4 is an int
The physical block diagram, Figure 5 is the CD output circuit 8ν~1 time h”
6 and 6 are timing charts, and FIG. 7 is a timing generation circuit diagram. SW...Ink face operation section CI)...CD release section TIMING...Timing light generation section■〕1
~D2. R1~1 also 2 modem ink face J) li
V, RCV part D1n~D2n, 1%1n~R2
n-Motemuire・'Tough Ace signal generic name C0NTR0L・・ICA interface! tilj's other issue DATA...IOA interface mode mutator information 1 Figure CPU Figure 2 PLI O 3 Figure Rotation 4 Figure 5

Claims (1)

[Claims] 1. In an online system, the connection between the central processing unit on the center side and the terminal device uses a double-layered communication method and a contention method, and in a system that uses a synchronous modem, contention is applied to the line concentrator. A control method for a recollection line concentrator, which is characterized in that it enables control.