JPH03258043A - Ais transmitter - Google Patents

Abstract

PURPOSE:To eliminate the need for a fixed stuff circuit by devising the transmitter such that a selector controlling a 1st extraction clock extracted from an input signal and a 2nd extraction clock extracted through other channel receiving an input with input signal interrupt information selects the 2nd extraction clock extracted through the other channel at the interrupt of the input signal. CONSTITUTION:An extraction clock 103 extracted from an input signal 102 is inputted to a selector(SEL) 1 together with an extraction clock 108 extracted through other channel and the SEL 1 is controlled depending on input signal interrupt information 101. In the absence of the input signal 102, an extraction clock 108 extracted through the other channel is selected as a write clock 109 to a buffer memory(BMEM) 2 to cause a stuff demand(SD) 100 between the write clock 109 and the readout clock 105 the same as the presence of the input signal 102. Thus, a fixed stuff generating circuit is not required.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an AI
This invention relates to a sending device for S.

[Conventional technology]

Conventionally, this type of AIS sending device, as shown in FIG.
B-M with the input signal ]02 as the write clock and the extracted clock 103 extracted from the input signal 102.
Writing to EM2, stuff demand (SD:
5tuff Demand) 106 is generated, but
Since there is no extraction clock 103 when the input signal 102 is disconnected, 5D106 cannot be generated. Therefore, the fixed stuff 110 generated by the fixed stuff generation circuit 4 is selected by 5EL3 according to the input signal disconnection information 101, and the B-MEM2
Alarm display signal (AIS: Alarm
Indication Signal ) transmission clock (read clock 105) was generated.

[Problem to be solved by the invention]

In conventional AIS sending devices, when the input signal is cut off, there is no extraction clock and SD cannot be generated, so the circuit configuration is such that the fixed stuff is selected from the fixed stuff generation circuit and sent out, so AIS is sent when the input signal is cut off. A disadvantage is that a circuit for generating a fixed stuff must be provided in order to generate the clock.

[Means to solve the problem]

The AIS sending device of the present invention uses a first extracted clock extracted on the receiving side as a clock when writing the input signal to the buffer memory on the receiving side of the input signal on the low-order group side of the asynchronous digital multiplexing device. or a second extraction clock extracted from another channel with an input signal, and the selector selects the second extraction clock extracted from the other channel when the input signal on the receiving side is disconnected. A from the buffer memory by selecting the clock
It has an AIS sending means for sending IS.

〔Example〕

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

FIG. 1 is a block diagram showing one embodiment of the present invention.

In FIG. 1, this embodiment has a buffer memory (hereinafter referred to as B-MEM) 2 into which an input signal 102 is written using a write clock 109, and an extraction clock 103 extracted from the input signal 102 or another input signal. A selector (hereinafter referred to as SEL) 1 that selects a write clock 109 from an extracted clock 108 from another channel based on input signal disconnection information 101, and a 1/4 period clock 1.
B-MEM2 when there is 07 and input signal disconnection information 101
An OR circuit 5 outputs a read clock 105 for the B-MEM 2 based on a logical sum with a stuff demand (hereinafter referred to as SD) 106 from the B-MEM 2.

The B-MEM 2 outputs a normal synchronization signal using the read clock 105 when the input signal 102 is normal, and outputs Al 5106 using the read clock 105 from the 5D 106 when there is input signal disconnection information 101.

Next, the operation of this embodiment will be explained.

The extracted clock 10B extracted from the input signal 102 is
It is input to 5ELL together with the extracted clock 108 extracted from other channels, and 5ELL is controlled depending on the presence or absence of input signal disconnection information 101. If there is no input signal 102, the extracted clock 10 extracted by another channel
By selecting 8 as the write clock 109 to the B-MEM2, 5D106 can be generated between the write clock 109 and the read clock 105 in the same way as when the input signal 102 is present, so the input signal 102 is disconnected. The clock (read clock 105) for sending out the Al5104 from the B-MEM 2 at the time can be generated without using a conventional fixed stuff generation circuit.

〔Effect of the invention〕

As described above, the present invention provides a first extracted clock extracted from an input signal and a second extracted clock extracted from another input channel on the receiving side of a low-order group of an asynchronous digital multiplexer. The clock has a selector controlled by input signal disconnection information, and this selector selects a second extracted clock extracted from another channel when the input signal is disconnected, thereby eliminating the need for a conventional fixed stuff circuit. This has the advantage that it is possible to generate the SD and create the clock for AIS transmission without using the SD.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing an example of a conventional AIS sending device. 1...Selector (SEL), 2...Buffer memory (B-MEM), 3...Selector (SEL)-4...
Fixed stuff generation circuit, 5...OR circuit, 101...
- Input signal disconnection information, 102...Asynchronous input signal, 10
3...Extraction clock, 104...Alarm display signal (AIS), 105...Reading clock, 106...
- Stuff Demand (SD: tuff demand) 7...1/4 period clock, O8...Extraction clock, 9...Write clock, 0...Fixed stuff.

Claims (1)

[Claims] When the input signal is written to the buffer memory on the receiving side of the input signal on the low-order group side of the asynchronous digital multiplexing device, the first extracted clock extracted on the receiving side or another channel with the input signal is used as the clock when writing the input signal to the buffer memory. a selector for selecting the second extracted clock extracted from the other channel; the selector selects the second extracted clock extracted from the other channel when the input signal on the receiving side is disconnected; An AIS transmitting device characterized by having an AIS transmitting means for transmitting AIS from.