JP3016984B2 - ISDN terminal adapter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ISND terminal adapter, and more particularly to an ISDN terminal adapter for transmitting and receiving data terminal interface signal monitoring data by circuit switching.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram showing an example of a conventional ISDN terminal adapter. 460 illustrates a 460 sub-rate multiplexed data terminal adapter.

FIG. 3 is a timing chart of data terminal interface points, line output points of a rate adapter, and data on the B channel.

In this example, I. As shown in FIG. 110 Rate adapter (hereinafter referred to as RAa) 11 having speed matching function
And rate adapter (hereinafter referred to as RAb) 12 and RAa1
1, a data terminal interface (DTEI) 13 and a DTEI 14 for connecting the RAb 12 and a communication port (RS-232c port) 9 respectively, a basic rate interface transceiver receiver LSI (BRI) 5 and a BPI 5 A shift register (hereinafter, SFT) 8 for delaying the frame pulse (hereinafter, FP) by half a cycle and inputting it to the RAa 12, and a data terminal control unit (hereinafter, DTEC) 17.

[0005] For the 110 speed matching method, 19.2k
Data of data terminal (hereinafter referred to as DTE) less than 8 bps
bps, 16 kbps, or 32 kbps. According to 460, an 8 kbps signal takes bit 1, a 16 kbps signal takes bits 1 and 2,
The 32 kbps signal is transmitted and received using bits 1, 2, 3, and 4. (The bit position in the B channel octet is
It is assumed that the first transferred bit is numbered 1 to 8 as the first bit. ) SFT FP from BRI5
8 and a half cycle delayed and input to RAb12, I.E. Since 460 subrate multiplexing can be performed, 1
Using two B channels, two D channels as shown in FIG.
The TE can communicate. "In FIG. 3, the data rate of the data terminal is 19,2 kbps, and" 1 ",.
“6” indicates transmission data (hereinafter, TxD) of DTE1,
"A" and "F" represent the TxD of DTE2, "1 '" and
“6 ′”, “A ′”,. 11
Indicates the 0 control bit. However, these codes represent only bit positions.

In addition, the conventional V.V. In the 110 speed matching method, E4 to E6 for transmitting network independent clock information
The bit and the E7 bit for establishing multi-frame synchronization when the user speed is 600 bps or less are unused (fixed to “1”) because the corresponding function is unnecessary.

[0007]

SUMMARY OF THE INVENTION 460
The sub-rate multiplexing scheme simply multiplexes one B channel to provide two logical channels. We were building a remote maintenance system.

Therefore, when constructing a remote maintenance system, data that can be transmitted and received as monitor signals is V.0 Since the 110 line switching is limited to three types of SD (transmission data signal), ER (data terminal ready signal) and RS (transmission request signal), other control lines RD (reception data signal), DR (data Set ready signal), CD (carrier detection signal), ST2 (transmission timing 2 signal), RT (reception timing signal), CS (clear to send signal), and CI (call indicator signal) can be monitored. There was a problem that it was not possible.

[0009]

SUMMARY OF THE INVENTION An ISDN terminal adapter according to the present invention has a CCITT-recommended interface characteristic V.11.
24 and V.I. 28, an ISDN basic interface access circuit, and an interface characteristic of the CCITT recommendation. CCIT with first and second speed matching circuits according to H.110
T. Recommendation I. An ISDN terminal adapter having a subrate multiplexing circuit with 460 characteristics, wherein a first control line among control lines from the ISDN terminal adapter to the data terminal is connected to a Sa bit input terminal of the second speed matching circuit. 2 control line Sb of the second speed matching circuit.
Connected to the bit input terminal and connected to the second
First transmitting means for transmitting each received signal to the line by connecting to the D bit input terminal of the speed matching circuit of the above, and the Sa bit and the Sb bit of the control line from the ISDN terminal adapter to the data terminal The third, fourth, fifth, and sixth control lines that cannot be mounted on A second transmitting means for transmitting the E4, E5, E6, and E7 bits shown in the bit map 110 to the line, and reading the E4, E5, E6, and E7 bits from the line to the monitor signal interface; Output means for outputting.

The first, second, third, fourth, fifth, and sixth control lines are respectively a carrier detection signal line,
It is a clear-to-send signal line, a transmission timing 2 signal line, a reception timing signal line, a data set ready signal line, and a call indicator signal line.

[0011]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of an ISDN terminal adapter according to the present invention, wherein (a) shows a transmitting side,
(B) shows the receiving side.

In FIG. 1, components having the same functions as in the conventional example are given the same abbreviations as in FIG. That is, as shown in FIG.
, RAb2, DTEI3, BRI5, central processing unit (hereinafter, CPU) 6, DTEC7, SFT8,
A communication port 9;
A monitor signal that cannot be carried over the D, Sa, and Sb bits of Ab2 is read. The DTEC 7 controls the communication port 9.

In the data terminal adapter on the monitor data transmission side, as shown in FIG. 1 (a), the DTEI3 is all input, and the signal on the communication port 9 is monitored and input to RAa1 and RAb2. I do.

That is, SD, ER, and RS from the communication port (RS-232c port) 9 are D, S of RAa1.
a, Sb, and RD, CD, C from communication port 9
S is input to D, Sa, and Sb of RAb2.

Then, D, Sa, of RAa1 and RAb2
Monitor signals ST2, RT, D that cannot be carried on the Sb bit
R and CI are periodically read out by the CPU 6 and transmitted on bits E4 to E7 of RAb2.

Further, the receiving side in the present embodiment is shown in FIG.
As shown in (b), RAa1, RAb2, and DTEI
4, a BRI 5, a CPU 6, an SFT 8, and a monitor port 10. The CPU 6 reads the E bit from RAb2.

In the data terminal adapter on the receiving side of the monitor data, as shown in FIG. 1B, DTEI4 is all output, and D, Sa, Sb of RAa1 and RAb2 are output.
Monitor signals ST, ER, RS, R received in bits
D, CD, and CS are output to the monitor port (RS-232c port) 10.

The CPU 6 periodically reads the E bit of RAb2 and outputs the remaining monitor signals ST2, RT and D.
R and CI are output.

[0020]

As described above, the present invention relates to I.V. 46
Monitoring of SD and RD by the 0 sub-rate multiplexing system and up to 12 arbitrary control lines using Sa, Sb and E bits (Sa × 2, Sb × 2, (E4, E4
By providing the monitoring function of (5, E6, E7) × 2), there is an effect that the signal of the data terminal interface can be fully monitored.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of an ISDN terminal adapter according to the present invention, wherein (a) shows a transmitting side and (b) shows a receiving side.

FIG. 2 is a block diagram showing an example of a conventional ISDN terminal adapter.

FIG. 3 is a timing chart of a data terminal interface point, a line output point of a rate adapter, and data on a B channel.

[Explanation of symbols]

1,2,11,12 Rate adapter (RAa, RA
b) 3,4V. 24 / V28 data terminal interface circuit (DTEI) 5 basic rate interface transceiver receiver (BPI) 6 central processing unit (CPU) 7, 17 data terminal control unit (DTEC) 8 shift register (SFT) 9 communication port (RS-232c port) 10 Monitor port (RS-232 port)

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsutomu Nozaki 1-4-2 Mita, Minato-ku, Tokyo Inside NEC Communication Systems Co., Ltd. (72) Inventor Hiroshi Oyama 4-2 Shimomata, Kakegawa-shi, Shizuoka Shizuoka Japan (56) References Takao Hayashi, ed., "Data Communication Using Modem and Telephone Network" (1988.3.520), CQ Publishing, p. 177-183 (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04L 12/02 H04L 29/10 H04M 11/00 303

Claims (2)

(57) [Claims] [Claim 1] V.1 of the interface characteristic of CCITT recommendation 24 and V.I. 28, an ISDN basic interface access circuit, and an interface characteristic of the CCITT recommendation. 11
CC with first and second speed matching circuits by zero
I.T. 460. An ISDN terminal adapter comprising a subrate multiplexing circuit with 460 characteristics.
The first of the control lines from the terminal adapter to the data terminal
Is connected to the Sa bit input terminal of the second speed matching circuit, the second control line is connected to the Sb bit input terminal of the second speed matching circuit, and the received data signal line is connected to the second bit matching terminal. First transmitting means for transmitting each received signal to a line by connecting to a D-bit input terminal of a speed matching circuit of
Among the control lines from the ISDN terminal adapter to the data terminal, the third, fourth, fifth, and sixth control lines that are not carried on the Sa bit and the Sb bit are connected to the V.4 terminal. 11
A second transmitting means for transmitting the E4, E5, E6, and E7 bits shown in the bit map of 0 to the line, and reading the E4, E5, E6, and E7 bits from the line to the monitor signal interface; An output terminal for outputting the ISDN terminal adapter. 2. The first, second, third, fourth, fifth, and sixth control lines include a carrier detection signal line, a clear-to-send signal line, a transmission timing two signal line, and a reception timing signal, respectively. 2. The ISDN terminal adapter according to claim 1, wherein said adapter is a line, a data set ready signal line, and a call indicator signal line.