JPH08107404A - Wrong connection monitoring device for transmitter and receiver - Google Patents

Abstract

PURPOSE: To prevent a transmitter and a receiver at different data speeds from being erroneously connected. CONSTITUTION: The transmitted data at the speed of a clock CKT at a transmission set frequency are received through an optical fiber 4 to a receiver 20. The frequency component almost equal with a clock CKR at a reception set frequency is extracted from the received transmitted data by a BPF 8-2 and its power level is detected by a level detector 8-3. When that power level does not reach a prescribed level, an alarm is issued and wrong connection is displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an erroneous connection monitoring device for preventing erroneous connection between devices having different transmission speeds, that is, a transmission device and a reception device in a communication system having several kinds of transmission speeds. In particular, it is suitable when applied to a camera device.

[0002]

2. Description of the Related Art An example of an outline of a conventional communication system is shown in FIG.
Shown in In the figure, reference numeral 10 is a transmitter, and a portion for creating transmission DATA to be transmitted is omitted. Further, reference numeral 20 denotes a receiving device, which shows the configuration up to the waveform reproducing section, and the transmitting device 10 and the receiving device 20 are connected by an optical fiber (fiber) 4 which is a transmission path.

Then, the transmitting device 10 emits light according to data output from D-type flip-flops (D / FF) 1 and D / FF 1 for normalizing transmission DATA to a clock (CK) speed of a transmission set frequency. Drive circuit 2 for driving D3 and transmission D by being driven by the drive circuit 2
It is composed of a light emitting element 3 for transmitting an optical signal modulated by ATA to an optical fiber. Further, the receiving device 20 receives the optical signal transmitted by the optical fiber 4 and converts it into an electric signal, a light receiving element 5, an amplifier 6 for amplifying an output signal of the light receiving element 5, and an amplified signal of a reception setting frequency. It is composed of a waveform reproducing unit 7 which reproduces a waveform using a clock (CK).

A communication system composed of the transmitting device 10 and the receiving device 20 having the above-mentioned configuration is, for example, a camera head unit (CH) of a camera device.
U) and camera control unit (Camera Contr
ol Unit: CCU). That is, the CHU and the CCU are interconnected by the optical fiber 4, and the image data captured by the CHU is sent from the transmitter 10 to the receiver 20 of the CCU via the optical fiber 4, whereby the image data captured by the CHU is sent. Can be played in the CCU.

[0005]

By the way, in the communication system in which the CHU and CCU of the camera device are interconnected by the optical fiber 4, there are several kinds of transmission speeds on the transmission side, and it is possible to cope with them. There are several kinds of transmission speeds on the receiving side as well. However, in such optical communication, since the control signal is not generally transmitted using a separate line, when the transmission distance between the transmission device 10 and the reception device 20 is long, the transmission device 10 having different transmission speeds.
There is a high possibility that the receiving device 20 will be erroneously connected, and there is a problem that a trouble is likely to occur.

If the connection is incorrect, the waveform cannot be reproduced and retimed on the receiving side, and communication becomes impossible. In order to eliminate erroneous connection, it is sufficient to know the mutual state of the CHU and CCU when laying the optical fiber 4 connected at the site, but the amount of work at the site is diverse and There is a problem that maintenance is difficult because of time constraints.

Therefore, an object of the present invention is to provide an erroneous connection monitoring device for a transmitting device and a receiving device which can prevent erroneous connection by displaying an alarm when the transmitting device and the receiving device are erroneously connected. There is.

[0008]

In order to achieve the above object, an erroneous connection monitoring device between a transmitter and a receiver according to the present invention transfers to a transmission line at a clock speed of a transmission set frequency set in the transmitter. In a receiving device that transmits transmission data and reproduces the transmission data received through the transmission path by a clock having a set reception setting frequency,
Receiving frequency detection means for detecting the clock speed of the received transmission data is provided, and when the clock speed of the transmission data detected by the reception frequency detection means is different from the reception setting frequency, reception with the transmission device is performed. An alarm is generated when it is determined that the device is erroneously connected.

Further, in the erroneous connection monitoring device between the transmitter and the receiver, the transmission path is an optical fiber, and the transmitter is a camera head
It is preferable that the transmission side of the unit section and the reception side of the camera control unit section be the reception side, and the alarm is provided on condition that the transmission data is received by the reception apparatus. May be generated.

[0010]

According to the present invention, when a transmitting device and a receiving device having different transmission speeds are connected to each other, it is determined that an incorrect connection has occurred and an alarm is generated. Therefore, it is possible to easily determine that an incorrect connection has been made. You can Further, when the distance of the transmission line is long, it is particularly effective because it is difficult to grasp the state of the transmission speed between the devices. Furthermore, if an alarm is generated when the data rate of the received data is different from the reception setting frequency on condition that the transmitted data is being received, it may be erroneous whether the transmitter / receiver or the transmission line is faulty. It is possible to easily determine whether it is a connection.

[0011]

FIG. 1 is a block diagram of an embodiment of an erroneous connection monitoring device between a transmitter and a receiver according to the present invention. In the figure, reference numeral 10 is a transmitter, and a portion for creating transmission DATA to be transmitted is omitted. Reference numeral 20 denotes a receiver, which shows the configuration up to the waveform reproducing section. The receiver 20 is provided with a reception frequency detection circuit 8 for monitoring erroneous connection between the transmitter 10 and the receiver 20. ing. The transmitter 10 and the receiver 20 are connected by an optical fiber 4 which is a transmission line.

Then, the transmitter 10 is set to the speed of the clock CKT from the D-type flip-flop (D / FF) 1 and D / FF 1 which normalizes the transmission DATA to the clock (CKT) speed of the transmission set frequency. It is composed of a drive circuit 2 that drives the light emitting element 3 according to data, and a light emitting element 3 that is driven by the drive circuit 2 to send out an optical modulation signal modulated by transmission DATA. In this case, the data transmission speed of the light modulation signal sent from the light emitting element 3 becomes the speed of the clock CKT, and this light modulation signal is transmitted through the optical fiber 4.

Further, the receiver 20 amplifies the output signals of the light receiving element 5 and the light receiving element 5 for receiving the light modulation signal transmitted through the optical fiber 4 and converting it into an electric signal so as to have a predetermined level. It is composed of an amplifier 6, a waveform reproducing section 7 for reproducing the amplified signal by using a clock (CKR) having a reception setting frequency, and a reception frequency detecting circuit 8. Further, the reception frequency detection circuit 8 has an optical signal input disconnection detection circuit 8-1 for detecting that the optical modulation signal is not input to the reception device 20, and the data transmission rate of the optical modulation signal is set in the reception device 20. It is composed of a bandpass filter (BPF) 8-2 for detecting whether or not the clock is substantially equal to the clock CKR and a level detection circuit 8-3.

A communication system composed of the transmitting device 10 and the receiving device 20 configured as described above is, for example, a camera head unit (CH) of a camera device.
U) and camera control unit (Camera Contr
ol Unit: CCU). That is, the transmission end of the CHU and the reception end of the CCU of the camera device are mutually connected by the optical fiber 4, and the image data captured by the CHU is transmitted from the transmission device 10 built in the CHU to the inside of the CCU via the optical fiber 4. The image data captured by the CHU can be reproduced in the CCU by sending it to the receiving device 20 incorporated in the.

By the way, as described above, CHU and CCU
There are several types of data rates for and, and each device is set to one of the data rates. Therefore, in order to perform communication, it is necessary to connect devices having the same data rate to each other to transmit and receive image data. However, as described above, there is a possibility that devices having different data rates may be connected to each other, and in order to prevent this, the reception frequency detection circuit 8 that monitors erroneous connection is provided.

That is, the reception frequency detecting circuit 8 is
An optical signal input break detection circuit 8-1 which detects that an optical modulation signal is not input and outputs an alarm signal, and an optical signal which receives only a frequency component substantially equal to the clock CKR set in the receiver 20. Extract from modulated signal B. P. F8-2 and a level detection circuit 8-3 which detects whether or not the power level of the frequency component substantially equal to the extracted clock CKR has reached a predetermined level and outputs an alarm when the power level has not reached the predetermined power level. It consists of and.

Therefore, an alarm is naturally generated when the optical modulation signal is not input to the receiving device 20, but the data transmission rate is set in the receiving device 20 even if the optical modulation signal is input. When it is different from the clock CKR, the level detection circuit 8-3 detects that the level has not reached the predetermined level, so that an alarm is generated. The level detection circuit 8-3 includes an optical signal input disconnection detection circuit 8-1 in order to prevent the influence of noise or the like.
Outputs an alarm on the condition that no alarm is output.

Therefore, when the receiving device 20 in which the clock CKR different from the clock CKT set in the transmitting device 10 is set, the B.C.
P. An alarm is generated from the level detection circuit 8-3 connected to the F8-2, and the alarm indicates that the incorrect connection is made on the display device or the like, so that the user can immediately determine the incorrect connection. Therefore, erroneous connection can be prevented. In this case, by making the mode displayed by the alarm output from the optical signal input disconnection detection circuit 8-1 different from the mode displayed by the alarm output from the level detection circuit 8-3, misconnection is prevented. It is possible to determine whether the transmission device 10 / reception device 20 or the transmission line (optical fiber 4) has a failure.

In the above description, as a means for detecting whether or not the data rate of the optical modulation data received by the receiving device 20 is equal to the set clock CKR, B. P. Although the means including the F8-2 and the level detection circuit 8-3 has been shown, the present invention is not limited to this, and when the level of the frequency discriminated signal is within a predetermined level range, for example, using a frequency discriminator and a comparison circuit. The comparison circuit may determine that the connection has been made normally, and the comparison circuit may determine that the connection has been made incorrectly when outside the predetermined level range.

The optical signal input break detection circuit 8-1 determines that the input is normal when the level of the detected output exceeds a predetermined level, for example, and the input is cut when the level of the detected output is below the predetermined level. It can be configured by a comparator. The B. P. A notch filter may be used instead of F8-2. The present invention is preferably applied to a camera device having an optical fiber as a transmission path as described above, but is not limited to this and can be applied to a communication system having a plurality of types of transmission rates. Is.

[0021]

As described above, according to the present invention, when a transmitting device and a receiving device having different transmission rates are connected to each other, it is determined that an erroneous connection has occurred and an alarm is generated. It can be easily judged. Therefore, it is possible to prevent normal reception data from being obtained due to timing mismatch due to different transmission setting frequency. Further, when the distance of the transmission line is long, it is particularly effective because it is difficult to grasp the state of the transmission speed between the devices. Furthermore, if an alarm is generated when the data rate of the received transmission data is different from the reception setting frequency on condition that the transmission data is being received, it may be erroneous whether the transmission / reception device or the transmission line is faulty. It is possible to easily determine whether it is a connection.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of an erroneous connection monitoring device for a transmitter and a receiver according to the present invention.

FIG. 2 is a block diagram of a communication system including a conventional transmitter, an optical fiber, and a receiver.

[Explanation of symbols]

 1 D / FF (D-type flip-flop) 2 Drive circuit 3 Light emitting element 4 Optical fiber 5 Light receiving element 6 Amplifier 7 Waveform reproducing section 8 Reception frequency detection circuit 8-1 Optical signal input break detection circuit 8-2 B. P. F (Bandpass Filter) 8-3 Level Detection Circuit 10 Transmitter 20 Receiver

Claims (4)

[Claims] 1. The transmission data is sent to a transmission line at a clock speed of a transmission setting frequency set in a transmitting device, and the transmission data received via the transmission line is converted by a clock of a reception setting frequency set. In the receiving device for reproduction, a reception frequency detecting means for detecting a clock speed of the received transmission data is provided, and the clock speed of the transmission data detected by the reception frequency detecting means is different from the reception setting frequency. In addition, an erroneous connection monitoring device between a transmitting device and a receiving device, wherein an alarm is generated by determining that the transmitting device and the receiving device are erroneously connected. 2. An erroneous connection monitoring device between a transmitter and a receiver according to claim 1, wherein the transmission path is an optical fiber. 3. The transmitter according to claim 1, wherein the transmitter is a transmitter of the camera head unit, and the receiver is a receiver of the camera control unit. Wrong connection monitoring device between transmitter and receiver. 4. The erroneous connection monitoring device between the transmitting device and the receiving device according to claim 1, wherein the alarm is generated on condition that the transmission data is received by the receiving device. .