JPH04284523A - Live line inserting and extracting system - Google Patents

Abstract

PURPOSE:To improve a working rate by preventing the disturbance of a bus signal, and preventing the breakdown of the electronic parts of a corresponding printed board or the malfunction of another printed board when an electronic device consisting of the printed board and a back plane is inserted or extracted for maintenance of inspection, etc., while electricity being applied. CONSTITUTION:The printed board 1 and the back plane 2 are connected through connectors 5 and 6, and the connectors 5, 6 are made into sequence connectors which are different in the lengthes of their terminals and constitute a three-stage sequence by the combination of their lengthes. On the other hand, the bus signal to/from the back plane is classified into three kinds of power supply, a signal for bus lock, and other bus signals, and they are assigned to each of the three- stage sequence, and the procedure of the first insertion-last extraction of the power supply and the lock of a bus buffer circuit are surely executed. Thus, the order of power supply bus signal signal for bus lock is secured at the time of the insertion, and the order of signal for bus lock bus signal power supply is secured at the time of the extraction.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for hot insertion and removal of printed circuit boards, in which electronic devices such as processors, programmable controllers, and telecontrollers are inserted and removed while the wires are live for maintenance and inspection purposes.

0002

[Prior Art] Generally, when a printed board is inserted into or removed from a connector for maintenance or inspection, the signal line and power line of the printed board are simultaneously connected or disconnected. When a common bus line is used, noise is generated on this bus line, which adversely affects the circuit operations of other printed boards. For this reason, hot-line insertion and removal, which involves inserting and removing a printed board from a connector while signals and power are being supplied, has conventionally been impossible. FIG. 6 is an explanatory diagram showing an example of signals and circuits exchanged between the printed board and the backplane. In the same figure, 1 is a printed board;
2 is a backplane, and the printed board 1 receives many signals from the backplane 2, including a power supply 3, an address bus 21, a data bus 22, a control bus 23, etc., via buffers 11, 12, and 13 to the printed board internal circuits. 1
4 and giving and receiving. While sending and receiving these signals,
When the printed board 1 is inserted or removed, it disturbs the bus signal on the backplane 2, leading to malfunctions of other printed boards and failure of electronic components on the printed board that have been hot inserted or removed.

[0003] This may impair the efficient maintenance and management of the system, and the applicant of the present invention also proposed
In Publication No. 503 and Publication of Utility Model Application No. 61-113549, by using a high-speed serial bus to exchange signals between printed boards, the effect on bus signals during hot insertion and removal is reduced, and if affected, We are proposing a protocol-based remedy. Further, Japanese Utility Model Publication No. 58-24394 and Japanese Utility Model Publication No. 59-4468 propose a method of avoiding the generation of the noise by avoiding turning on the signal and power at the same time.

0004

[Problems to be Solved by the Invention] However, the conventional hot-swap system using a serial bus has poor performance compared to the parallel bus system, which can send and receive a large number of signals at the same time. A conversion circuit is required, which increases costs, and VMEBUS and Mu
It cannot be applied to printed circuit boards that use international standard CPU buses such as ltibus2.

The present invention was devised in view of these problems, and it is possible to replace a faulty printed board with any type of printed board in a energized state, and to replace a faulty printed board in an instrumentation system without stopping the entire system. The purpose of the present invention is to provide a hot-line insertion/removal method that allows the addition or deletion of devices, prevents bus signal disturbances and malfunctions of other boards during hot-line insertion/removal, and improves the operating rate of devices and systems.

[0006]

[Means for Solving the Problems] Means for solving the above problems in the present invention is to energize an electronic device comprising a plurality of printed boards and a backplane provided with a pattern for connecting bus signals between the printed boards. In the hot insertion/removal method, which inserts/removes the printed circuit board while the backplane bus signals are classified into three types: power, bus lock signals, and other bus signals.
Allocate to each stage sequence, ensure the procedure of first insertion and later removal of the power supply and locking of the bus buffer circuit,
A hot-line insertion/removal method is used in which the power supply, bus signal, and bus lock signal are applied in this order during insertion, and the bus lock signal, bus signal, and power supply are removed in this order during removal.

[0007]

[Operation] The present invention utilizes a commercially available sequence connector to realize hot insertion and removal of printed circuit boards. Generally, an electronic device is composed of a printed board with a specific function and a backplane with a bus signal pattern for exchanging signals between the printed boards.
By connecting terminals with sequence connectors with different lengths, you can configure a three-stage sequence by combining terminals with different lengths of plugs and sockets, while also connecting bus signals to the backplane with power, bus lock signals, It is classified into other bus signals and assigned to each of the three-stage sequences. When inserting, turn on the power supply → bus signal → bus lock signal in this order, and when removing it, make sure to remove it in the order of bus lock signal → bus signal → power supply. When inserting, the bus lock signal turns ON at the same time as the power terminal is turned on, and turns OFF when the bus lock signal terminal is turned on. When removing it, the bus lock signal terminal turns ON after removal, and when the power terminal is removed, the bus lock signal turns ON. A bus lock circuit is mounted on the printed circuit board to lock the signal bus buffer using this circuit, which is generated so as to remain ON until the signal is turned on. During hot insertion and removal, if the power supply is inserted first and then removed, and the bus buffer circuit is locked, it is possible to prevent bus signal disturbance and prevent damage to the electronic components mounted on the printed circuit board that is being inserted and removed. It is also possible.

[0008]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partially cutaway perspective view showing an example of a rack configuration of an electronic device embodying the present invention. In the figure, 1
2 is a printed board, 2 is a backplane, 3 is a power supply, and 4 is a subrack. The printed board 1 and the backplane 2 are connected by a connector. The connectors include plug type and DIN (Deutsche Industry
There are two types of connectors: a DIN connector type and a DIN connector type. hand,
By fitting them together, the printed board 1 and the backplane 2 are connected. As the plug 5 and socket 6, there are known sequence terminals as shown in Figs. 2(a) and 2(b), which have longer terminal lengths than standard. It becomes possible to insert the signal first and remove it later.

In the present invention, the signals exchanged between the printed circuit board 1 and the backplane 2 are classified into three types: power supply, bus lock signal, and other signals. These use the sequence connectors, use sequence terminals and standard terminals for each classification, and provide a time difference between input and removal of signals when hot-swapping printed circuit boards. The table below shows an example of a combination in which each signal terminal is assigned to a three-stage sequence.

0010

[Table 1]

FIG. 3 is a waveform diagram of the sequence of turning on or removing each signal terminal during hot-line insertion and removal based on such assignment. The sequence shown in the figure is configured into a three-stage sequence by combining the sequence terminals and standard terminals of the plug and socket, and as a result, as shown in the first to third stages in the figure, the power terminal is connected to the power terminal when inserted. → Bus signal terminal → Bus lock signal terminal is inserted in this order, and when removed, bus lock signal terminal → Bus signal terminal → Power supply terminal is removed in this order. Here, this bus lock signal terminal is used to generate a bus lock signal that locks a bus signal buffer connected to the backplane during hot insertion/removal.

FIG. 4 is a block diagram of a bus buffer lock circuit that performs the above-described generation operation, and shows an example of a circuit that implements the present invention in the electronic device shown in FIG. In the figure, three sequence terminals [1], [2] and [3] correspond to sequences [1], [2] and [3] in Table 1,
The bus lock signal terminal [3] is not connected to other Ov terminals in the printed board internal circuit 14 in FIG. 6. The bus lock signal is generated by a bus lock signal as shown in the third and fourth stages of FIG.
2 and 13, and turn O after inputting the bus lock signal.
Become FF and unlock. Also, when removing it, first
It remains ON until the power supply terminal is removed and the power terminal is turned to N, and the bus buffers 11, 12, and 13 are reliably locked during insertion and removal of the board to prevent disturbance of the backplane bus signal. Furthermore, by inserting the power source first and removing it later, it is possible to prevent the electronic components of the printed board from being destroyed. Here, the reason why the bus signal and the bus lock signal were not set in the same sequence is as follows.
This is because even in the same sequence, there is a slight time difference between input and removal between terminals during insertion and removal, and there is a possibility that the bus signal is input or removed before the bus lock signal is turned ON. The reason why the power supply and the bus signal terminal are arranged in different sequences is to ensure that the power supply is inserted first and removed later with respect to the bus signal.

[0013] Since the insertion and removal of printed circuit boards is usually performed by humans, the operating speed varies, and the time difference between the three types of terminals depends on the operating speed. If you want to keep the bus lock signal ON for a certain period of time or more when inserting a printed circuit board, if you install a timer 51 as shown in FIG. 5, you can easily set the time T1 as shown in the fifth and sixth rows of FIG.
can be turned ON.

In this embodiment, since hot insertion and removal are possible, a faulty board can be replaced while the redundant printed circuit board is energized. In an instrumentation system, it is necessary to replace a faulty printed circuit board or to insert or remove a printed circuit board to add or delete a loop by stopping only a part of the loop without stopping the entire system, but this embodiment makes this possible. Make it. In addition, when hot-swapping printed circuit boards, the procedure of first inserting and then removing the power supply and the locking of the bus buffer circuit can be performed reliably, which prevents bus signal disturbances and malfunctions of other printed boards. It is also possible to prevent the destruction of electronic components mounted on the printed circuit boards that carry out the process, and as a result, the effect of significantly improving the operating rate of devices and systems is clear.

[0015]

[Effects of the Invention] As described above, according to the present invention, it is possible to replace a faulty printed board in a redundant printed board while the power is on, and to add or delete a loop in an instrumentation system without stopping the entire system. It is possible to provide a hot-line insertion/removal method that prevents bus signal disturbance and other printed circuit board malfunctions during hot-line insertion/removal, and improves the operating rate of devices and systems.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of the connector of the present invention.

FIG. 3 is a waveform diagram of a signal sequence in the embodiment.

FIG. 4 is a configuration diagram of a bus buffer lock circuit.

FIG. 5 is a circuit diagram of a bus lock circuit.

FIG. 6 is a configuration diagram of a conventional example.

[Explanation of symbols]

1...Printed board, 2...backplane, 3...power supply, 4...
Subrack, 5...Plug, 6...Socket, 11, 12,
13...buffer, 14...printed board internal circuit.

Claims (1)

[Claims] Claim 1: In a hot-swapping method in which an electronic device is inserted and removed while the power is on, the electronic device is made up of a plurality of printed boards and a backplane with a pattern for connecting bus signals between the printed boards, and the terminals have different lengths. , the printed circuit board and the backplane shall be connected through a sequence connector that constitutes a three-stage sequence by the combination of lengths,
Bus signals with the backplane are classified into three types: power, bus lock signals, and other bus signals, and are assigned to each of the three-stage sequences described above. When inserting, power → bus signal →
The bus lock signal is turned on in this order, and when removed, it can be removed in the order of bus lock signal → bus signal → power supply. When inserted, it turns on at the same time as the power terminal is turned on, and turns off when the bus lock signal terminal is turned on. However, at the time of removal, the bus lock signal turns ON after removal and remains OFF until the power terminal is removed.
A bus lock circuit is provided that generates a bus lock signal that continues N and uses it to lock the bus buffer circuit of the signal connected to the backplane. A hot-swap system that is characterized by reliable locking of the bus buffer circuit.