JPS6228901B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a check code sending method in data transmission using pushbutton dial signals.

Generally, when transmitting data via communication lines,
Various types of signals are used, but
In some cases, push button dial signals are used as they are for data transmission, partly because the circuit can be constructed economically.

In this case, there are 12 types of pushbutton dial signals (0 to
9, 〓, #) signals. Therefore, there is no problem with data transmission, but in a device that transmits a check code using a parity check method, for example, if the check code is a banal code such as "C", "D", "E", etc. A problem arises when this code cannot be sent.

The present invention was devised in view of this point, and makes it possible to send a check code in all cases.

Hereinafter, the present invention will be explained in detail with reference to embodiments of the drawings. Figure 1 is a block diagram, and Figure 2 is an example of a check code, where a is a conventional sending code and b is an example of a check code.
is a sending code according to the present invention, and FIG. 3 is a data frame according to the present invention.

In FIG. 1, 1 and 2 are a plurality of gate circuits that accept input data, 3 is a timing pulse generation circuit, to which the output of an oscillator 4 is applied, and a timing pulse output 3a for data transmission.
(START~END) and timing pulse output 3b (TIMG A,
TIMG B). Timing pulse output 3a for data transmission
(START~END) are the multiple gate circuits 1,
The control pulse is given as two control pulses, and input data is sequentially taken in. Reference numeral 4 denotes a check circuit for transmitting a check code, which is composed of, for example, a flip-flop circuit corresponding to each bit, and is controlled by the timing pulse output 3a, and performs a bit check for each unit of input data. Output CECK1 to CECK8 each time
changes. 6 is a 4-bit 2-channel multiplexer, which outputs the timing pulse 3b mentioned above.
(TIMG A, TIMG B) via the output circuit 7, and the output TIMG A connects the A channel A.
1~A4 is output TIMG B and B channel B1~
B4 is selected. In addition, the corresponding inputs A3, B3, A so that bit outputs Q3, Q4 are always output as "0"
4, B4 is the output CECK1 of check circuit 4
This is done independently of CECK8.

Reference numerals 8 to 11 denote output circuits, and the outputs Q1 to Q4 of the multiplexer 6 and the input data accepted by the gate circuits 1 and 2 are respectively inputted via lines 5. 12 is a decoder which selects and oscillates one of the low group frequencies L1 to L4 and high group frequencies H1 to H3 of the pushbutton dial signal oscillator 13 according to the output of the above-mentioned output circuit, and causes the pushbutton dial signal oscillator 13 to oscillate by selecting one of the low group frequencies L1 to L4 and high group frequencies H1 to H3 according to the output of the above-mentioned O/W circuit. Sends a button dial signal (MF signal). 13a,
13b is a connection terminal to a communication line (telephone line, etc.).

Next, the operation will be explained in detail.

By being supplied with the output of the oscillator 4, the timing pulse generation circuit 3 sequentially sends out timing pulse outputs 3a for data sending from START to END. As a result, gate circuits 1 and 2 are controlled, and input data are sequentially accepted. The input data is input to the output circuits 8 to 11 via the line 5, and the output thereof is given to the decoder and decoded, so that, as described above, a push button dial signal corresponding to the input data is sent to the communication line. Ru. On the other hand, the accepted input data is input to the check circuit 4 and bit checked each time, and outputs CECK1 to CECK8 are obtained each time. Since this is not accepted until pulse output 3b (TIMG A, TIMG B) is given, its output Q
1 to Q4 are not sent.

The timing pulse generation circuit 3 sends out the timing pulse output 3a for sending out data, and then sends out the timing pulse output 3b for sending out a check code in the order of TIMG A and TIMG B, so that the output TIMG A is sent out. At this time, the multiplexer 6 outputs the check outputs CECK1 and CECK2 connected to the A channel among the check outputs CECK1 to CECK8 sent out by the check circuit 4 by the data timing pulse output END.
Also, when the output TIMG B is sent out, the check output CHCK4, which is connected to the B channel,
Accepts CECK8 and outputs them Q1,
Q2, and uses this as a check code to send out a corresponding push button dial signal.

To explain this with reference to Fig. 2, the check code that is sent after data is generally sent out is the output CECK1 to CECK8 of the check circuit 4 as it is as a binary equal code, as shown in Fig. 2a. There is. However, as described above, in a device using a push button dial signal, if the binary equal code becomes "C", "D", "E", etc., it cannot be sent.

FIG. 2b shows the transmission of the check code according to the present invention as described above. As can be seen from the above explanation, the binary equal code of the check outputs CECK1 to CECK8 is divided into the upper 2 bits and the lower 2 bits. are shifted in time and sent out in correspondence with the binary equal code "1" and "2". At this time, the bits corresponding to the binary equal codes "4" and "8" are always sent as "0", so "C", "D", and "E"
A binary equal code does not occur. Therefore, the check code can be sent within the range of the pushbutton dial signal.

In addition, on the side receiving the data, the data code is
After receiving END, the above divided 2
Needless to say, the bit check code is temporarily stored in a register and converted into a 4-bit binary equal code to be decoded. The circuit for this is
Since it can be constructed using a normal electronic circuit, illustration thereof is omitted.

As described above, according to the present invention, a check code can be sent in data transmission using a push button dial signal which is relatively easy to use, so data transmission can be performed with fewer misidentifications.

[Brief explanation of the drawing]

FIG. 1 is a block diagram according to the present invention, FIG. 2 is an example of a check code, in which a is a conventional sending code, b is a sending code according to the present invention, and FIG. 3 is a data frame according to the present invention. 1, 2...gate circuit, 3...timing pulse sending circuit, 4...check circuit, 6...multiplexer, 12...decoder, 13...push button dial signal oscillator.

Claims (1)

[Claims] 1 In data transmission in which data is sent using a pushbutton dial signal, the 4 bits of the binary equal code sent out as a check code after sending the data are divided into the upper 2 bits and the lower 2 bits, and each A check code sending method in data transmission using a push button dial signal, characterized in that a corresponding push button dial signal is sent.