JPH0773309B2 - Busy signal transmission system in NO7 signal device with chaining function - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] The present invention relates to a busy signal transmission system in a NO7 signal device, and a busy signal transmission system in a NO7 signal device having a chaining function capable of prompt transmission when there is a busy transmission instruction. The purpose is to use HD with the chaining function via a common signal link
In a NO7 signal device that sends and receives LC format messages, a busy send instruction hard register that is set by a busy send instruction from a higher-level device is provided, and an HDLC sending unit that has a chaining function is provided with a busy signal generating unit.
When the busy sending instruction hard register is set, the sending unit suspends the chaining function, and the sequence number held by the BSN hard register in the busy signal generating unit and the sending sequence number in the sent frame held by the sending unit And a busy code generated from the fixed code generating means to generate a busy message, form a new busy message at the head, and form a new chaining followed by an untransmitted message and send it.

[Field of Industrial Application] The present invention relates to a busy signal transmission system in a NO7 signal device.

NO7 common line signaling device standardized by CCITT (hereinafter, simply
The NO7 signaling device) is used for transmitting various control signals and data between the exchange and other devices via a common line signal link independent of a communication path such as voice. Then, the NO7 signal device transmits and receives data in HDLC (high-level data link control procedure) format, and conventionally, control signals corresponding to each channel (each communication path such as a communication path) of the HDLC format are continuously chained. And then send. On the other hand, CCITT's recommendation stipulates that when a busy state (congestion state) occurs in the higher level (higher level of the protocol), a busy signal is sent to the signaling device of the partner station to notify the busy state. .

However, when the signal transmission using the chaining in the HDLC format is performed as described above, it is difficult to immediately transmit the busy signal, and its improvement is desired.

[Prior Art] FIG. 3 shows an explanatory view of a NO7 signal device, and FIG. 4 shows a signal form on the common line signal line.

FIG. 3 shows an example in which a plurality of terminals such as telephones are respectively connected to the exchanges 30 and 32 for simplification of explanation, and a communication line 31 for communication between the terminals is provided between the exchanges. Is provided (for multiple channels), and for transmitting control signals (selection signals for network formation, etc.) to each switching device.
NO7 signal devices 33 and 35 are provided, and a common signal line 34 for transmitting a control signal is provided between the NO7 signal devices.

The NO7 signal device sends control signals corresponding to each communication line (channel) to a message signal unit (displayed as MSU).
, MSU1, MSU2, and so on. Then, the data in HDLC format is preceded and followed by a flag (indicated by F in FIG. 4), and the transmission sequence number (FSN: forward sequence number) and reception sequence number (BSN: backward sequence number) are added to the data part.
Or check signal (FCS: frame check sequence)
Etc. are attached.

FIG. 5 (a) shows a conventional MSU transmission procedure by chaining. In the figure, CE indicates the state of chaining and becomes "1" when chaining continues and "0" when chaining ends.

This chaining function is a descriptor (Descriptor)
When the control code is set in, the hardware for transmission is connected and START / STOP is performed, the chaining process is executed by the firmware program and the sending operation is performed.
Therefore, the firmware only chains the descriptors, and the normal device itself does not need to know how far the transmission has ended, and the processing is left to the hardware.

On the other hand, according to CCITT's 1984 recommendation, a busy signal indicating the reception buffer busy (the original name is Signal Indication
sy, which may be displayed by this initial "SIB") is added to control sending and receiving.
The signal is set to have a high priority because it notifies the partner station that it is busy and requests that the partner stop transmission.

The conventional method for transmitting the busy signal will be described. After the transmission of the chained MSU data as shown in FIG. 5 (a) is started, even if there is a busy signal transmission instruction, the chaining is performed as it is. After sending all MSUs, a busy signal is sent, and priority sending cannot be performed.

Therefore, when the descriptor being transmitted based on the already chained information has been transmitted, it receives a suspend specification (Suspend: interrupt of interruption), and when it has completely stopped, it restarts chaining with the busy signal at the beginning. .

(Note that when suspend is executed, the transmission data is lost, and the idle pattern is continuously transmitted to the line.) A conventional busy transmission sequence diagram is shown in FIG. 5 (b). In this figure, if suspend is applied during the transmission of MSU1 for the first time, the chaining process will stop due to the interruption of the hardware, create a busy signal frame, start it and chain the untransmitted message signal MSU2 and below to transmit it. Is to do.

FIG. 5 (c) shows a flow chart of a conventional busy sending program. In this flow, a busy frame is generated by a busy transmission request (Fig. 51), but at this time, HD
The transmit sequence number (FSN) and receive sequence number (BSN) required for LC format signal frames are not included.

That is, in the NO7 signal device, it is stipulated that a sequence number is added to each one as described above, and each frame of the message (MSU) is sequentially given a different number. For frames other than messages, use the frame number of the frame sent immediately before (same number).

Therefore, after the suspension is requested by 52 in FIG. 5 (c) to request the interruption, and after waiting (until the transmission of the message frame in the middle of transmission is completed), the suspend is executed, and then the current processing is performed by the program processing. Search the descriptor's transmission sequence number (FSN), copy the obtained sequence number to the busy signal frame, and use it for the other BS.
Obtain N (this is the sequence number of the message frame that was successfully received) from the hardware of the NO7 signaling device to create the HDLC frame. After that, by forming a chain with untransmitted message frames (MSU2 or lower) and restarting (56 in FIG. 5 (c)), the fifth
It is transmitted sequentially as shown in FIG.

[Problems to be Solved by the Invention] As described above, each NO7 signal system has a sequence number (FNS), and in a transmission circuit having a chaining function, the sequence number is not the time when the signal is transmitted to the line. , Updated when the chaining process is performed. Therefore, when the busy signal is preferentially transmitted, the FSN value of the busy signal must be set with the FSN value actually sent to the line.

Therefore, conventionally, the procedure is to suspend the communication being transmitted, check the FSN value of the final transmission signal by the program, set the FSN value, and then send the busy, and control the program for that. There is a problem that the signal transmission becomes complicated and time-consuming, and the signal transmission cannot be executed promptly after the busy instruction is generated.

It is an object of the present invention to provide a busy signal transmission system in a NO7 signal device having a chaining function that enables quick transmission when there is a busy transmission instruction.

[Means for Solving the Problems] FIG. 1 shows a basic configuration of the present invention.

In FIG. 1, 8 is a memory control unit including a chaining control unit 9, and 10 is a BSN holding a reception sequence number BSN.
A hard register, 11 is a busy send instruction hard register that is set by an instruction from a higher level when a buffer busy state occurs, 12 is an HDLC sending unit, 13 is a frame creating unit, 14 is a sending unit, 15 is a busy signal generating unit, 16 Is a fixed code generating means, and 17 is a signal generating means.

According to the present invention, when the busy transmission instruction is set in the busy transmission instruction hard register, the BSN (reception sequence number) of the hard register holding the BSN value and the second word (transmission sequence number: FSN) of the frame which has been transmitted last time are set. It is used to generate and send a busy signal by obtaining other necessary words from the fixed code generating means and incorporating them in the hardware.

[Operation] After the busy sending instruction of FIG. 1 is given to the busy sending instruction hard register 11 from the upper layer, when the HDLC sending unit 12 issues the next frame request to the memory control unit 8, this instruction is set. The busy signal generator 15 is driven.

As a result, in the signal generating means 17 in the busy signal generating section 15, the SIB code (represented by 1 byte, "05" is used in 16 signal code) from the fixed code generating means 16 and the LI code (length indicator: LI Display and if busy code 1
Each code of "01" representing the byte length is set in the storage units 174 and 173 through the gate 161 opened by the output of the busy sending instruction hard register 11 because of the byte length.

Further, the BSN hard register 10 stores a reception sequence number BSN which is asynchronously updated by a NO7 control program section (not shown), and the content thereof is stored in the signal generation means 17 in the busy signal generation section 15. It is set in part 171.

On the other hand, the content of the frame transmitted last time remains in the transmission unit 14 (it disappears when the next transmission data enters), and the second
A word FSN (1 byte) passes through the gate 161 opened by the set output of the hard register 11 and is set in the storage unit 172 of the signal generating means 17.

The busy signal generator 15 notifies the frame generator 13 that the 4-byte signal is generated. As a result, the frame creation unit 13 executes processing for reconfiguring the chaining under the control of the chaining control unit 9 of the memory control unit 8 (chaining the head of the untransmitted MSU with the busy signal frame as the head). In that case, the signal generated by the busy signal generator 15 is then input from the path to the frame generator 13 and is subjected to processing such as flagging and then sent from the transmitter 14. When the busy signal frame is transmitted, the HDLC transmission unit 12 generates a signal for resetting the busy transmission instruction hard register 11,
Stop outputting the send instruction. This busy signal is transmitted for one frame every fixed period.

[Embodiment] FIG. 2 shows a block diagram of an embodiment of the present invention.

In FIG. 2, 20 is a NO7 control device, 21 is a processing device (CP
U), 22 is a memory, 23-1 is a SIB (busy) register in which a busy transmission instruction is set, 23-2 is a BSN register that holds the BSN value updated by the processing device, and 24 is a dynamic with a first chaining function. Memory control circuit, 25 is HDLC
A sending circuit, 26 is a dynamic memory control circuit with a second chaining function, and 27 is an HDLC receiving circuit.

The processing device 21 is connected to a processing device such as an exchange (not shown).
In accordance with the NO7 signal control program 211, the HDLC transmission circuit 25 and the reception circuit 27 are controlled via the first and second dynamic memory control circuits 24 and 26 with the chaining function so that the N
It controls the transmission and reception of signals through the O7 controller and the common line signal line. The HDLC transmission circuit 25 includes a SIB generation circuit 2 according to the present invention.
51 is provided, the BSN (reception sequence number) of the BSN register 23-2, the FSN (transmission sequence number) of the transmitted frame of the transmission register (not shown) in the HDLC transmission circuit 25,
SI generated by the built-in fixed code generator (16 in Fig. 1)
A code composed of a plurality of bytes forming a busy signal is generated by the B code and the LI code.

The chaining function forms a chain of MSUs (created at a higher level) to be transmitted in the memory 22 by the first dynamic memory control circuit 24 with the chaining function under the program control of the built-in firmware. HDLC
The receiving circuit 27 has the same configuration as the conventional one, checks the received frame, restores the original MSU from the HDLC format, and stores it in the memory
Store in 2.

When the reception buffer busy occurrence is detected by the NO7 signal control program 211 in the processing device 21 during the control of the signal transmission / reception, the SIB (busy) sending program 212 is activated, the SIB register 23-1 is set, and the SIB sending instruction is first issued. It is supplied to the dynamic memory control circuit 24 with a chaining function, and then also to the HDLC detection circuit 25.

As a result, the HDLC transmission circuit 25 sequentially transmits the busy signal generated by the SIB generation circuit 251 according to the principle shown in FIG. 1 as a frame in HDLC format before issuing the next frame transmission request. When the transmission of the busy signal is completed, a transmission request is sent to the first dynamic memory control circuit 24 with the chaining function, and the SIB register 23-1 is reset.

The busy signal is instructed to be sent out at a constant cycle unless the upper state changes, and the same operation as above is performed each time.

[Effect of the Invention] According to the present invention, even if a frame is being transmitted by a long chaining when the NO7 signal device is congested in the device itself, the interruption for the busy signal transmission is eliminated, so the processing speed is increased. Can be achieved.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of the present invention, FIG. 2 is a configuration diagram of an embodiment of the present invention, FIG. 3 is an explanatory diagram of a NO7 signal device, and FIG. 4 shows a signal form on a common line signal line. FIG. 5 (a) is a diagram showing a conventional MSU transmission procedure by chaining, FIG. 5 (b) is a conventional busy transmission sequence diagram, and FIG. 5 (c) is a flow diagram of a conventional busy transmission program. Is. In FIG. 1, 10: BSN hard register 11: busy sending instruction hard register 12: HDLC sending unit 13: frame creating unit 14: sending unit 15: busy signal generating unit 16: fixed code generating unit 17: signal generating unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyofumi Mise 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Hiroyo Masuko 1015, Kamedotachu, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited

Claims (1)

[Claims] 1. A NO7 signal device for transmitting and receiving HDLC format messages using a chaining function via a common line signal link, is provided with a busy send instruction hard register (11) set by a busy send instruction from a host device. , An HDLC transmission unit (12) having a chaining function includes a busy signal generation unit (15), and the HDLC transmission unit (12) suspends the chaining function when the busy transmission instruction hard register (11) is set. At the same time, the sequence number held by the BSN hard register (10) in the busy signal generation section (15), the transmission sequence number in the transmitted frame of the transmission section (14), and the fixed code generation means in which the busy code is set in advance ( A busy message is created by the output of 16), and the created busy message is placed at the beginning and unsent messages continue. A busy signal transmission method in a NO7 signal device having a chaining function characterized by forming and transmitting a new chaining.