JPH0654359A - Enable control system for output circuit - Google Patents

Abstract

PURPOSE:To prevent indefinite data transmission at the time of inserting circuits for processing identical signals contained in respective packages relating to a system for preventing the transmission of undefinite data from the circuits. CONSTITUTION:A first circuit 2 provided with a signal input part 1 and a second circuit 4 provided with a signal output part 3 for processing the identical signals are contained in the respective packages and the respective packages are respectively inserted to prescribed positions and power source is respectively supplied. Output is generated after the lapse of a prescribed holding time after turning on the power source by providing power source monitoring circuits 5 and 6 in the first and second circuits 2 and 4 and the signal output part 3 in the second circuit 4 is made operable at the time of the output generation of the both power source monitoring circuits 5 and 6 by providing an enable control part 7. Thus, after inserting the first and second circuits 2 and 4, after the lapse of the holding time of the circuit inserted later, the signal output part 3 generates output signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for preventing the transmission of uncertain data from a circuit, and more particularly, by controlling the enable of a buffer at power-on in a remote multiplex transmission equipment of a digital exchange. The present invention relates to an enable control system for an output circuit, which prevents uncertain data from being transmitted when a package is inserted.

In a central office switch, a large number of optical modules, control circuits, etc. are required with the adoption of an optical transmission system. However, due to the mounting space of the package, it is divided into a plurality of packages according to their functions and mounted. The method of doing is often adopted.

In such a case, even if the package is hot-swapped, it is necessary to prevent the sending of uncertain data when the package is inserted by controlling the enable of the buffer when the power is turned on. In this case, the buffer enable control method is required not to be affected by chattering at the time of package insertion.

[0004]

2. Description of the Related Art In a central office switching system, a large number of optical modules and control circuits have come to be used with the adoption of an optical transmission system. In some cases, the sending unit and the signal receiving unit cannot be housed in the same package,
In that case, a method is adopted in which each function is divided into a plurality of packages and accommodated.

In this case, the signal sending unit and the signal receiving unit are
Since it is in a separate package and has its own power supply, the low-order device side must be stopped until the operation of circuits in the package stabilizes after both packages are inserted. There is a risk that uncertain data will be sent to the lower device and the lower device may malfunction.

Conventionally, when package insertion is detected,
A method for preventing such a problem from occurring is generally used by enabling a signal output buffer for a lower device.

FIG. 4 shows a conventional enable control method for an output circuit, showing a case of a mounting information type control method for detecting and controlling package mounting.
Is a diagram showing a circuit configuration, and FIG. 6B is a diagram showing an example of an output waveform when a package is inserted. In the figure, A indicates a signal sending unit and B indicates a signal receiving unit, which are housed in separate packages. Further, 11 is a signal output buffer, 12 is a mounting information signal line, and 13 is an optical signal light receiving circuit including, for example, an optical module. When the package of the signal sending unit A and the package of the signal receiving unit B are inserted into separate predetermined positions in a housing (not shown), the circuits in the respective packages operate via respective connectors (not shown). It is configured to be supplied with a power source for the operation.

In the circuit of FIG. 4, a signal based on the optical interface from the higher-order device is received by the signal receiving unit B.
It is input to the optical signal receiving circuit 13 and converted into an electric signal. The signal output buffer 11 sends this signal to the lower device.

At this time, both packages are inserted into the signal output buffer 11 through the mounting information signal line 2 and
When it is connected to the ground via the partner package, it is released from the enable state and becomes operable, and by sending a signal, sending of uncertain data to the lower device is prevented.

In this case, the signal transmitter A and the signal receiver B
Since the order of inserting the packages is not specified in (1) and (2), there are cases where the package of the signal sending unit A is inserted first and cases where the package of the signal receiving unit B is inserted first.

FIG. 5 shows the flow of the mounting information type control system, where (a) shows the case where the signal transmission section is inserted first, and (b) shows the case where the signal reception section is inserted first. Is shown.

In FIG. 5A, the package of the signal sending unit A is inserted first, and then the package of the signal receiving unit B is inserted, so that the signal output buffer is passed through the signal of the mounting information signal line 12. 11 is shown to be unenabled.

Further, in FIG. 5B, the package of the signal receiving section B is inserted first, and then the package of the signal transmitting section A is inserted to output the signal via the signal of the mounting information signal line 12. It is shown that the enable of the buffer 11 is released.

[0014]

In the conventional method shown in FIG. 4, when the package is inserted, the enable signal given through the mounting information signal line 12 may be in the chatter state until it is determined. In such a case, there is a problem that the signal output buffer 11 outputs a signal including uncertain data as shown in FIG. 4B, for example, which may cause a malfunction in the lower device.

The present invention is intended to solve the above-mentioned problems of the prior art, and a power supply monitoring circuit is used to set an arbitrary hold time when a package is inserted and the power is turned on in the package. It is possible to suppress the release of the enable to the buffer until the operation of the circuit of is stabilized, and the hot plugging of the package
It is an object of the present invention to provide an enable control method for an output circuit that reliably prevents the transmission of uncertain data.

[0016]

[Means for Solving the Problems] (1) FIG. 1 shows a principle configuration of the present invention. The present invention relates to a first circuit 2 having a signal input section 1 for receiving an input signal and a second circuit having a signal output section 3 for generating an output signal, for performing related processing on the same signal. In a device in which 4 and 4 are housed in separate packages and power is supplied separately by inserting each package into a predetermined position, a predetermined power is supplied to the first and second circuits 2 and 4. Provided are power supply monitoring circuits 5 and 6 that generate outputs when the hold time has elapsed, and an enable control unit that enables the signal output unit 3 in the second circuit 4 when both power supply monitoring circuits 5 and 6 generate outputs. 7 is provided, and after the insertion of the first and second circuits 2 and 4, the hold time of the circuit inserted later has elapsed, the signal output unit 3 generates an output signal.

(2) In the present invention, at this time, the signal input section 1
Is an optical signal light receiving circuit 13 for converting an optical signal input from a higher-level device into an electric signal, and the signal output unit 3 is composed of a signal output buffer 11 for generating an output signal to the lower-level device by this electric signal. .

(3) Further, in the present invention, in this case, the signal input section 1 has a function of detecting a break in the input optical signal from the host device and outputting a light input break detection signal, and the enable control section 7 is provided. The signal output unit 3 is made operable by the outputs of the two power supply monitoring circuits 5 and 6 and the generation of the light input break detection signal.

[0019]

(1) In a device in which the signal sending unit and the signal receiving unit of the central office switch are housed in separate packages, each package has its own power source, so each package has its own power source. Until the power is turned on,
In order to prevent uncertain data from being sent to the lower device, the enable signal for the output buffer is controlled.

In this case, in the prior art, the output control of the buffer is controlled by the mounting information from the related package. However, according to this method, the enable control for the buffer is released by the mounting information immediately after the package is inserted.

Therefore, the buffer may be released from being enabled before the circuit in the package, which is powered on later, becomes stable, which causes uncertain data to be transmitted, causing malfunction in the lower device. It happened.

On the other hand, in the present invention, the power supply monitoring circuit is used to set an arbitrary hold time to generate the enable control signal, and the enable control of the buffer is performed using this signal. I have to.

Therefore, according to the present invention, it is possible to control so as to release the enable of the buffer after the circuit in the inserted package becomes stable, so that the uncertain data is sent to the lower device. Can be reliably prevented.

(2) In the case of (1), the signal input section 1 is composed of an optical signal light receiving circuit 13 for converting an input optical signal from the host device into an electrical signal, and the signal output section 3 is subordinate to the electrical signal. It can be applied to the case where the input signal is an optical signal and the output signal is an electric signal by configuring the signal output buffer 11 that generates an output signal for the device.

(3) Further, in the case of (2), the signal input section 1 is provided with a function of detecting the interruption of the input optical signal from the host device and outputting the optical input interruption detection signal, and the enable control section 7 is provided. When the input optical signal from the host device is cut off by enabling the signal output unit 3 by the outputs of the both power supply monitoring circuits 5 and 6 and the generation of the optical input break detection signal,
By prohibiting the output signal to the lower device, it is possible to prevent the transmission of uncertain data to the lower device when the input optical signal from the upper device is disconnected.

[0026]

FIG. 2 shows an embodiment of the present invention, showing a configuration of a power supply monitoring type control system, (a) showing a circuit configuration, and (b) showing a package insertion. It is a figure which shows the example of an output waveform. The same components as those in FIG. 4 are denoted by the same reference numerals, 14 and 15 are power supply monitoring circuits provided in the signal transmitting unit A and the signal receiving unit B, and 16 is a buffer control signal generating circuit.

In FIG. 2A, the signal based on the optical interface from the host device is received by the package of the signal receiving section B, and the optical signal receiving circuit 13 converts the optical signal into an electric signal. The electric signal generated by the conversion is sent to the package of the signal sending unit A, and the signal output buffer 1
It is sent to the lower device through 1.

The power supply monitoring circuits 14 and 15 are, for example, MB3.
Like 771 (manufactured by Fujitsu), when a power supply (5V) is turned on, a signal that becomes "L" and becomes "H" after a certain hold time is generated. The value can be arbitrarily set. By using this signal, enable control of the signal output buffer 11 is performed. Buffer control signal generation circuit 16
Is, for example, an AND circuit, and the dual power supply monitoring circuit 14,
A logical product signal of 15 signal outputs is generated.

In this case, the signal transmitter A and the signal receiver B
Since the order of inserting the packages is not specified in (1) and (2), there are cases where the package of the signal sending unit A is inserted first and cases where the package of the signal receiving unit B is inserted first. In the following, the two cases will be described separately.

FIG. 3 shows the flow of the power supply monitoring type control system, where (a) shows the case where the signal transmission section is inserted first, and (b) shows the signal reception section inserted first. The case is shown.

As shown in FIG. 3A, when the package of the signal transmitting section A is inserted first, the power supply monitoring circuit 14 operates and outputs a signal of "H" after a predetermined hold time. In this case, since the package of the signal receiving unit B is not inserted, the signal of the power supply monitoring circuit from the package of the signal receiving unit B does not become "H". Therefore, the output of the buffer control signal generation circuit 16 does not become "H", and the signal output buffer 11 is kept in the enabled state.

Next, when the package of the signal receiving unit B is inserted, the optical signal receiving circuit 13 operates to send the signal from the host device to the package of the signal transmitting unit A. The power supply monitoring circuit 15 does not output the "H" signal until a predetermined hold time has elapsed.

When the power supply monitoring circuit 15 outputs a signal of "H" after the lapse of a predetermined hold time, the output of the buffer control signal generating circuit 16 becomes "H" and the signal output buffer 11 is released from the enable state. Therefore, the signal from the optical signal receiving circuit 13 is sent to the lower device.

In this case, the signal receiving unit B inserted later
By setting the hold time of the power supply monitoring circuit 15 in the above package to be longer than the time required for the power supply in the circuit of the signal receiving unit B to stabilize, the package of the signal transmitting unit A and the package of the signal receiving unit B are After the insertion, the operation of both circuits becomes stable, and then the enable of the signal output buffer 11 is released. Therefore, uncertain data is not sent to the lower device, and malfunction does not occur in the lower device. Absent.

As shown in FIG. 3B, when the package of the signal receiving section B is inserted first, the optical signal receiving circuit 13 operates to convert the optical signal from the host device into an electrical signal and stabilize it. The signal is sent to the package of the signal sending unit A.
Further, the power supply monitoring circuit 15 operates and outputs a signal of "H" after a predetermined hold time.

In this case, since the package of the signal transmission unit A is not inserted, the signal of the power supply monitoring circuit 14 in the package of the signal transmission unit A is not "H".
Therefore, the output of the buffer control signal generation circuit 16 is
It does not become "H", and the signal output buffer 11 is kept in the enabled state.

Next, when the package of the signal transmission unit A is inserted, the power supply monitoring circuit 14 in the package of the signal transmission unit A does not output the "H" signal until a predetermined hold time has elapsed.

When the power supply monitoring circuit 14 outputs the "H" signal after the lapse of a predetermined hold time, the output of the buffer control signal generating circuit 16 becomes "H" and the signal output buffer 11 is released from the enable state. Therefore, the signal from the optical signal receiving circuit 13 is sent to the lower device.

In this case, the signal transmission unit A inserted later
By setting the hold time of the power supply monitoring circuit 14 in the above package to be longer than the time required for the power supply in the circuit of the signal sending unit A to stabilize, the package of the signal sending unit A and the package of the signal receiving unit B are After the insertion, the operation of both circuits becomes stable, and then the enable of the signal output buffer 11 is released. Therefore, uncertain data is not sent to the lower device, and malfunction does not occur in the lower device. Absent.

As described above, when the enable control method for the output circuit of the present invention is used, the transmission of uncertain data can be surely suppressed, and the output waveform is illustrated in FIG. 2 (b). Thus, it does not include indeterminate data.

In the circuit shown in FIG. 2, there is a risk that uncertain data will be sent to the lower device even when the optical transmission line signal from the upper device is disconnected.
The optical input disconnection detection circuit built in the optical signal light receiving circuit 13 detects the optical signal disconnection from the higher-level device and outputs the optical input disconnection detection signal. By adding 16 logical conditions, the signal output to the lower device can be stopped even when the optical transmission line signal from the upper device is disconnected.

In this case, since the optical input break detection signal is output from the optical signal receiving circuit 13 with a predetermined hold time, the optical transmission line signal from the host device is cut off. Uncertain data is not sent from the signal output buffer 11 to the lower device.

[0043]

As described above, according to the present invention, the first circuit having the signal input section and the second circuit having the signal output section are housed in separate packages and separately provided. In the device that supplies power, the enable of the signal output unit is canceled when the hold time of the circuit inserted later elapses. Therefore, it is possible to prevent uncertain data transmission due to chattering when the package is inserted. Therefore, it is possible to prevent malfunction in the lower device.

Further, in this case, since the signal input section detects the break of the input optical signal and generates the optical input break detection signal, the signal output to the lower device is prohibited. It is possible to prevent the transmission of uncertain data to the lower device due to the interruption of the input optical signal from the upper device.

[Brief description of drawings]

FIG. 1 is a diagram showing a principle configuration of the present invention.

2A and 2B are diagrams showing an embodiment of the present invention, in which FIG. 2A is a diagram showing a circuit configuration, and FIG. 2B is a diagram showing an example of output waveforms when a package is inserted.

FIG. 3 is a diagram showing a flow of a power supply monitoring type control system, in which (a) shows a case where a signal transmission unit is inserted first,
(B) shows the case where the signal receiving unit is inserted first.

4A and 4B are diagrams showing a conventional output circuit enable control system, in which FIG. 4A is a diagram showing a circuit configuration and FIG. 4B is a diagram showing an example of output waveforms when a package is inserted;

FIG. 5 is a diagram showing a flow of a mounting information type control method, in which (a) shows a case where a signal transmission unit is inserted first,
(B) shows the case where the signal receiving unit is inserted first.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 signal input part 2 1st circuit 3 signal output part 4 2nd circuit 5 power supply monitoring circuit 6 power supply monitoring circuit 7 enable control part 11 signal output buffer 13 optical signal light receiving circuit

Claims (3)

[Claims] 1. A first circuit (2) having a signal input section (1) for receiving an input signal for performing related processing on the same signal, and a signal output section (3) for generating an output signal. A second circuit (4) provided with a power source and a second circuit (4) are housed in separate packages, and power is supplied separately by inserting each package into a predetermined position. The circuit (2, 4) is provided with a power supply monitoring circuit (5, 6) that generates an output when a predetermined hold time has elapsed after power is turned on, and the output of the both power supply monitoring circuits (5, 6) An enable control unit (7) for enabling the signal output unit (3) in the second circuit (4) is provided, and after the insertion of the first and second circuits (2, 4), When the hold time has elapsed, the signal output unit (3 ) Generates an output signal, the enable control method of the output circuit. 2. An optical signal receiving circuit (1) in which the signal input section (1) converts an input optical signal from a host device into an electrical signal.
3. The enable control method of the output circuit according to claim 1, wherein the signal output unit (3) comprises a signal output buffer (11) for generating an output signal to a lower device according to the electric signal. . 3. The signal input section (1) has a function of detecting a disconnection of an input optical signal from a higher-level device and outputting an optical input disconnection detection signal, and the enable control section (7) has the dual power sources. The enable control system of the output circuit according to claim 2, wherein the signal output section (3) is made operable by the output of the monitoring circuit (5, 6) and the generation of the optical input break detection signal.