1. Field of the Invention
The present invention relates to an oil-resistant, water-resistant electronic instrument setting apparatus used when setting the addresses of a master station and a plurality of slave stations connected to a transmission line and also used when performing the initial setting of a control unit in a transmission control system used in a work environment requiring oil resistance and/or water resistance.
2. Description of the Related Art
In a transmission control system in which a parent station and slave stations are distributed along a transmission line, the address setting for each station has been performed by an address switch or the like within the master station and the slave stations.
The environment for setting the address of each of the slave stations is required to be a highly clean one, and considering the setting work, the environment requires intervals between each setting section. In addition, any work undertaken after the setting work has been completed is complicated.
For example, Patent Document 1 describes an oil-resistant rubber switch and an electronic instrument using the same switch. Performing address setting using such an oil-resistant rubber switch, however, requires a large area for the installation location of the switch and as such, downsizing of the equipment cannot be achieved.
[Patent Document 1] Japanese Patent Application Laid-Open Publication No. 2003-086055 Oil-resistant rubber switch and electronic instrument using the same switch
The application system of Patent Document 1 requires a wide space for performing installation adjustments and setting work cannot be performed in a small area.
The method described in Patent Document 2 requires a sealing structure in order to achieve an oil-resistant structure, thereby resulting in a cost increase in the end products.
The present invention hermetically seals the electrical settings of an instrument and performs the setting thereof using an optical communication method, thereby eliminating the need for an oil-resistant sealing structure for the setting section and thereby protects the electronic circuits.
One feature of the present invention is to eliminate an oil-resistant sealing structure and perform the address setting and initial setting of a control unit in a reduced space, at a reduced size and at low cost.
A non-limiting feature of the present invention eliminates the oil-resistant seal structure and allows both address and initial setting of a control unit to be performed using light or electromagnetic induction.
According to one aspect of the present invention, there is provided a console and control/monitor terminal, which is a control/monitor signal transmission system including a plurality of controlled devices each of which includes a controlled section and a sensor section for monitoring the controlled section, wherein a control signal is transmitted as a transmission signal to the controlled section through a data signal line common to the plurality of controlled devices and a monitor signal from the sensor section is transmitted as a transmission signal, and which is a transmission control system connected to a transmission line provided with a master station which is connected to the data signal line and transmits a monitor signal transmitted from a predetermined controlled device as a control signal for a controlled device associated in advance and a plurality of slave stations which are provided in association with the plurality of controlled devices and are connected to the data signal line and corresponding controlled devices, wherein the address setting and initial value setting of the slave station are optically communicated to a data-setting-circuit-equipped console through a light transmission window of the slave station, wherein the slave station includes a light emitting element and a light receiving element for performing address setting and initial value setting, and wherein the data-setting-circuit-equipped console is provided with a light emitting element and a light receiving element. This structure eliminates the need for a switch structure for address setting and can reduce failure factors such as deterioration failure and faulty contacts in a switch section. Performing address setting and initial data writing using the light emission signal through the light transmission window allows the control/monitor terminal to be hermetically-sealed from the outside and to maintain airtightness, thereby providing an oil-resistant, water-resistant structure.
According to another aspect of the present invention, there is provided the console and control/monitor terminal as detailed above, which is the control/monitor signal transmission system which transmits a control signal to the controlled section through the common data signal line and transmits a monitor signal from the sensor section to the data signal line, wherein the same address is set for a light receiving section unit and a light emitting section unit, each of which is a slave station, the control signal is sent as a light emission signal from the light emitting section unit in the same clock cycle of the same address of the transmission signal, is received as a monitor signal by the light receiving section unit during the light emission period of the light emission signal, and is sent as the transmission signal to the common data signal line. The light reception signal received by the light receiver as the monitor signal is sent as an input signal, or a current signal, to the transmission line. Since the input signal, or the monitor signal, indicates the presence of an object to be detected, the master station can recognize the presence of the object to be detected by the monitor signal of that address. Since the addresses of the light emitter side and the light receiver side are the same, the light emission timing and the light reception timing operate in sync with each other. An other light emission signal is not received by mistake, thereby allowing highly reliable detection of the object to be detected to be performed.
This structure can immediately reflect input information in the output signal, allowing the response speed of each sensor to be increased. The input signal as the current signal is obtained in the first-half low voltage level part. With the first-half pulse width as the input signal, an output signal as the current signal may be carried in the latter-half low voltage level.
According to another aspect of the present invention, there is provided the console and control/monitor terminal as detailed above, wherein the light emitting section unit and the light receiving section unit in pairs are set to be the same address of the transmission signal in order to constitute a transmission sensor, wherein a plurality of the transmission sensors constitute an area sensor for detecting an object to be detected within a specific area. A plurality of light emitters and light receivers in pairs are used to constitute a sensor area, wherein either a part of or all the monitor signals detect the presence or absence of the object to be detected, thereby achieving the area sensor.
According to another aspect of the present invention, there is provided the console and control/monitor terminal system as detailed above, wherein only a managing slave station provided at the top of cascade-connected slave stations is provided with the light emitting element and the light receiving element which optically communicates with the data-setting-circuit-equipped console through the light transmission window, and when the address or initial setting value of the managing slave station is set by the data-setting-circuit-equipped console, an address generated by the managing slave station is set for the dependent slave station which is cascade-connected to the managing slave station, and successively added address values are taken over by a cascade line, allowing the address or initial value of the dependent slave station to be successively set. In this case, a plurality of cascade-connected control/monitor terminal systems do not require address setting and this has the advantage of simplifying the address setting work and initial data setting work at the time of system startup and system change.
According to another aspect of the present invention, there is provided the console and control/monitor terminal system as detailed above, wherein a freely deformable wiring or support structure is provided between the data-setting-circuit-equipped console and a tip section provided with the light emitting element and the light receiving element. The control/monitor terminal system using a wire-saving technique for reducing wiring can reduce not only the amount of wiring but also the size of the installation location and thereby downsize the system itself. A work area when setting work is performed manually is not required, and the setting operation can be performed by simply bringing the light emitting section and the light receiving section into close contact with the light transmission window. The light emitting section, the light receiving section, and the data-setting-circuit-equipped console can perform address setting and initial data setting easily, even if there is only sufficient space through which the freely deformable wiring or support structure can pass, thereby achieving both downsizing and space-saving easily.
According to another aspect of the present invention, there is provided the console and control/monitor terminal system as detailed above, wherein a control/monitor terminal provided with a communication section which optically communicates with the data-setting-circuit-equipped console protects a circuit of the control/monitor terminal which has a hermetically-sealed structure. The console and control/monitor terminal system is suitable for use in an oil-dispersing environment, a humid environment, or a reactive-gas environment.
According to another aspect of the present invention, there is provided the console and control/monitor terminal system as detailed above, wherein the tip section provided with the light emitting section and the light receiving section connected to the data-setting-circuit-equipped console through a freely deformable wiring or arm structure is half-fixed to the light transmission window provided with the communication section of the control/monitor terminal for performing optical communications using magnetic material fixing, fitting, engagement, or hook in order to provide a structure wherein a light transmitting/receiving section can be fixed during optical setting. This fixing method allows for stable setting work without impairing communication accuracy due to vibrations or fluctuations during address or initial data setting work. Installation and adjustment can be performed in the above-described narrow location, thereby achieving downsizing, weight reduction, and cost reduction across the entire system.
According to another aspect of the present invention, there is provided the console and control/monitor terminal system as detailed above, wherein the data-setting-circuit-equipped console constituting the console is operated by a battery or a secondary battery, and when it is operated by the secondary battery the console includes a charging circuit.
According to another aspect of the present invention, there is provided the console and control/monitor terminal system as detailed above, wherein the power source of the data-setting-circuit-equipped console is connected to a signal transmission line or a power line in order to receive a power supply. This can potentially downsize or even eliminate a battery or secondary battery within the console, thereby achieving downsizing and weight reduction of the console.
According to another aspect of the present invention, there is provided the console and control/monitor terminal system as detailed above, wherein as a substitute for light, electromagnetic communications are performed through a nonmagnetic hermetically-sealed casing structure. In a state of waiting for adjustment after installation, a master station operation of the control/monitor terminal system is set to be in a non-operating state, and the slave station receives the write command and following address signal sent from the console to the transmission line. By using an operation in which the slave station stores the address as its own address through the removal of a reflective tape on the slave station, the address of the slave station from which the reflective tape has been removed is then set. The console, on completion of the address setting of the slave station, increments the address number and sends it to the transmission line. The reflective tape of the slave station is then removed in order to set the address of the next slave station. Until the address number reaches the one input in the console in advance, the above-described operation is repeated in order to complete the address setting.
According to another aspect of the present invention, there is provided the console and control/monitor terminal system as detailed above, wherein the data-setting-circuit-equipped console constituting the console is connected to the signal transmission line, all sensor windows of the control/monitor terminals for which the address is set are optically sealed to achieve internal reflection, an address non-setting state is recognized, and at the time of address setting an address is set in order of removing the seal.
The control unit and setting device of the present invention can easily provide an oil-resistant structure.
Hereinafter, the control unit and setting device of the present invention will be described on the basis of the embodiments included herein with reference to the drawings.
The oil-resistant control unit and setting device of the present invention will be described with reference to
In
In order to perform address setting and initial data setting, a specific address of a control/monitor terminal is set through a rotary switch and a DIP switch by opening a plastic cover in an address switch part attached to the control/monitor terminal. In this regard, switches and electronic circuits are protected from adhesion of surrounding dust and contamination simply by means of the plastic cover. In the automation of machine assembly factories and food factories, however, in an oil mist or humid environment, oil and water drops enter switches and electronic circuits, causing failure through faulty contacts and insufficient circuit insulation.
The present invention provides the switches and electronic circuits of a control/monitor terminal with a perfect hermetically-sealed structure in order to make the structure resistant to an oil mist or humid environment and this allows the address setting and initial data setting of the control/monitor terminal to be performed using optical communications through the light transmission window 33. In this case, given the structure of the data-setting-circuit-equipped console and the light transmission window 33, a sealing method and a communication setting section used herein must simultaneously satisfy the requirement of being low-priced, have good operability, be small, and have excellent reliability.
At the lowermost column of
In
When the address or initial set value of the managing slave station 43 is set by the data-setting-circuit-equipped console 26, an address generated by the managing slave station is set for the dependent slave station 46, which is cascade-connected to the managing slave station, and successively added address values are taken over by a cascade line, allowing the address or initial set value of the dependent slave station 46 to be successively set.
In
After performing the initial setting, the light receiving phototransistor is then in the standby state in order to receive a light emitting signal from the data-setting-circuit-equipped console 26. The signal from the console 26 is sent as a console side LEDC signal, as shown in the address writing flow chart in
Then, an LEDA signal 16 (shown in
In
Although
On the uppermost part of the figure, I/O address time intervals are shown. Each time interval assigned to each address from “0” to “3” is t0 period. When a current Is, or an input signal, is detected on the front side t0/4 of the time interval, as shown in the I/O address “2” and I/O address “3,” by receiving the detection signal, the residual 3t0/4 output signal is made “High” to reflect the input signal in the output within the same address signal. When this technique is used, the current Is, or the input signal, is received in the first half t0/4 while the latter half 3t0/4 is made “High,” thereby allowing both input and output to be performed within one pulse cycle. Reflecting the input in the output within one pulse cycle simultaneously is defined as full-duplex communication. When full-duplex communication is used, by setting the same address for the light emission side of the transmission sensor terminal 11 and the light reception side of the transmission sensor terminal 11 shown in
In the figure, the sensor system 11 outlined by the broken border on the left of the figure is the light receiving section of the transmission sensor terminal, while the sensor system 11 outlined by the broken border on the right of the figure is the light emitting unit of the transmission sensor terminal. The same address is programmed to be set for the light emitting unit and the light receiving unit connected to the transmission line DP signal line 7 and the DN signal line 8, and, in addition, the address setting is set to be the same address, thereby configuring a pair of transmission sensor terminals.
In the figure, the data-setting-circuit-equipped console 26 is a unit for performing the address setting and initial data setting of the control/monitor terminal. The light emitting section and the light receiving section of the reflection sensor terminal are separated, and each of them is controlled by each MCU 27, thereby constituting the transmission sensor terminal. By performing optical communications with the data-setting-circuit-equipped console 26 through the light transmission window 33 of the control/monitor terminal as the slave station, both address setting and initial value setting are performed. The control/monitor terminal as the slave station provided with the light emitting element and the light receiving element for performing the optical communications and the data-setting-circuit-equipped console 26 provided similarly with the light emitting element and the light receiving element allow address setting and initial value setting to be undertaken in an oil-resistant structure.
The optical communications are performed through the light transmission window 33. As a substitute for light, electromagnetic communications may be performed through a nonmagnetic hermetically-sealed casing structure (not shown).
The address setting for the sensor section 9 is completed by the communication procedure shown in
An LEDC signal 31 emitted from the console includes a StartBit indicating the start of the signal, a write command for instructing address writing, and address data n. The sensor terminal receives a series of these LEDC signals 31 from the console as the INA signal 17 and returns the LEDA signal 16, as a verification signal, to the console. The console captures the LEDA signal 16 as the INA signal 17, thereby allowing the setting completion display and the set address display on the console to be performed.
When a communication control system is installed or a control/monitor terminal device is replaced, in order to perform the address setting and the initial data setting of the control/monitor terminal device, a person who performs the setting work inputs address data and initial setting data required for the data-setting-circuit-equipped console 26 from the KEY input section 28. The display section 29 displays the data and displays data input instructions, the input mode state, and the monitor state of the control/monitor terminal device. The KEY input section 28 includes a data input key and a function key for mode switching and constitutes the console together with the display section 29. In
The data-setting-circuit-equipped console 26 constituting the console is operated by a battery and a secondary battery. The secondary battery includes a rechargeable circuit.
The CPU 10 performs initialization using an initialization program PRG4 stored in the ROM 13 concurrently with power-on, while on completion of the KEY input of address setting data, a transfer key is pressed in order to allow the LEDC signal 31 to be transmitted through the signal line section 34 from the light emitter of the light emitting/receiving section 30 to the control/monitor terminal. When the LEDC signal 31 reaches the communication setting section 24 from the light transmission window 33 of the control/monitor terminal device, the address setting and initial data setting of the control/monitor terminal device are written. The communication procedure for the writing/reading is performed as shown in below-described
In the figure, the data-setting-circuit-equipped console 26 includes the KEY input section 28, the display section 29, and a power switch 36, and is connected to the light emitting/receiving section 30 via a connector 35 through the signal line section 34.
In order to perform the address setting and the initial data setting of the control/monitor terminal device, a person who performs the setting work, when a communication control system is installed or a control/monitor terminal device is replaced, inputs predetermined address settings and initial data settings through the operation of a KEY of the KEY input section 28 while viewing the display contents of the display section 29 and presses the transfer key of the KEY input section 28 in order to allow a data signal to be emitted from the light emitter.
When the power switch 36 is turned on, together with the initialization of the MCU, the initial setting program and the address setting program PRG4 within the ROM 13 are performed. On the display section, the option as to whether address setting is performed, the transfer of the initial data is performed, or the set address is checked is selected by the function setting key, starting the communications from the console to the sensor terminal. In the figure, the signal line section 34 is designed to be freely deformed, bringing the light emitting/receiving section 30 into contact with the light transmission window of the control/monitor terminal device, of which the address is set, thereby allowing address setting operations to be easily performed even in a narrow space.
In the figure, the connection from the connector 35 to the light emitting/receiving section 30 through the signal line section 34 is not limited to the flexible type like the signal line section 34 shown in
In this case, a permanent magnet may be installed around the light emitting/receiving section 30 in order to allow it to be electromagnetically fixed to the light transmission window 33 of the control/monitor terminal device. Stability during communications may be achieved by a fitted structure or a hook (not shown).
A tip section provided with a light emitting element and a light receiving element connected to the data-setting-circuit-equipped console 26 through flexible wiring or an arm structure is half-fixed to a light transmission window provided in a communication section for performing the optical communications for a control/monitor terminal by a fixture method using the attraction force of magnets and magnetic material fixing, a mechanical fit/engage structure, or a hook in order to allow the light transmitting/receiving section to be fixed during optical communication setting, thereby providing the control/monitor terminal system and the light emitting/receiving section 30 with a structure suitable for performing optical communications stably.
In the figure, the transmission line DP signal line 7 and the DN signal line 8 carry +24V, or the peak pulse voltage of the DN signal line 8, with respect to 0V, while the DN signal line 8 carries a signal which is lower than +24V by the equivalent of the wave height of a signal pulse. The signal starts with a StartBit, followed by ADRS0 data and ADRS1 data with the number of control/monitor terminal devices connected to the transmission line, and returns to a StartBit again. The StartBit has a length five times longer than the data signal and is identified as a start signal.
The control/monitor terminal device rectifies part of the signal of the transmission line DP signal line 7 and the DN signal line 8 and obtains a power source by charging a capacitor.
The method for obtaining a power source provides a wire-saving structure.
The MCU 27 receives the CK signal 15 obtained by the CK signal extraction circuit 21 as a basic input signal in order to allow the master station and each slave station to operate as a communication control system. A light emission signal of the first sensor section 9 positioned at ADRS0 emits light at a first pulse leading edge after the StartBit in order to obtain a light reception signal PHTS1, which is the reception of a detection signal of the object to be detected as reflected light by the phototransistor. Similarly, it emits light at a second pulse leading edge in order to obtain a reception signal PHTS2, which is the reception of a detection signal of the object to be detected as reflected light by the phototransistor. Light emission signals LEDSn and light reception signals PHTSn of n sensor sections 9 are thus obtained. When a signal of the last nth sensor section 9 is obtained, the signal returns to a StartBit again in order to repeat the cycle.
In the figure, address reading is performed by the LEDC signal 31 transmitted from the console. The console, when performing address reading, transmits a read command immediately after STB1 as a StartBit. The sensor terminal receives the read command immediately after STB1 as a StartBit, then transmits the address data n of the sensor terminal immediately after STB1 StartBit as the LEDA signal. The console receives the LEDA signal as the INC signal in order to read the address data n.
In the example of the transmission sensor terminal, as shown in the figure, a light emitting unit 39 and a light receiving unit 40 are placed across an object to be detected 42. In this example, they are fixed to a pipe rack 37. The pipe rack 37 constitutes a three-dimensional rack using a connecting part 38. A plurality of sensor terminals is installed on the transmission line using a T-branch connector or the like. The transmission line fixes the wire with wiring fixing members 41 which are appropriately spaced apart. In the transmission sensor terminal, in contrast to the reflection sensor which shows the presence of the object to be detected when reflected light is present, the reception signal is LOW in the presence of the object to be detected and is HIGH in the absence of the object to be detected.
In this case, the light emitting section unit 39 and the light receiving section unit 40, which are a plurality of control/monitor terminal systems connected to the common data signal line DP signal line 7 and the DN signal line 8, have a structure incorporating a plurality of pairs of transmission terminal systems. The same address is set for the light emitting section unit 39 and the light receiving section unit 40 by the console 26 of the present invention, and the address value is set for the address of the light emitting circuit and the light receiving circuit following a managing slave station within the light emitting section unit 39 or light receiving section unit 40 by a cascade connection. The addresses of the plurality of light emitting circuits or light receiving circuits of the light emitting section unit 39 and the light receiving section unit 40 can thus be set in pairs. The detection result of the object to be detected which has been detected by a plurality of light emitting circuits and light receiving circuits in pairs is sent to the master station connected to the common data signal line DP signal line 7 and the DN signal line 8. The master station converts the detection result signal received as a serial signal into a parallel signal and transmits whether the object to be detected has been detected by the detection circuits forming a pair or the detection circuits forming a plurality of pairs through the input unit of the control section.
When such an area sensor is constituted, for each address of a plurality of light emission sides and a plurality of light reception sides, setting only the address of the managing slave station to which the top address is assigned allows the address of the dependent slave station to be successively set on an incremental basis by a cascade connection, thereby allowing address setting to be performed in a short time.
In the conventional detection system for an object to be detected using a plurality of light emitters and light receivers, a problem often occurs in which a light emission signal for the next sensor or another separate sensor is detected by a light receiver. By using a signal processing system which obtains an input signal as a current signal in the pulse-first-half low-voltage level part of a pulse cycle constituting an address and reflects the input signal result in the pulse-latter-half pulse width and outputs it, the light receiver does not receive the light transmission signal for the next sensor or another separate sensor by mistake and therefore, a highly reliable area sensor can be provided. In addition, use of the above-described address setting method of the managing slave station allows an address setting operation to be easily performed at the time of control/monitor terminal device installation or unit replacement.
The light emitting section unit 39 in the figure includes the light transmission window 33 for writing an address and a light emitting section 44. The light receiving section 40 also has a light receiving window (not shown) for receiving the light emitted from the light emitting section 44, and they are positioned facing each other. The light emitting section unit 39 and the light receiving section unit 40 are placed with their optical axes optically aligned. In this case, the same address is set for the light emitting section unit 39 and the light receiving section unit 40, and this can be processed as the presence/absence sensor signal of the object to be detected within one pulse, as in the case of the reflection signal.
The mechanism in which the same address is set for the light emitting section unit 39 and the light receiving section unit 40, and the mechanism in which the light receiving section is operated with the light emission timing of the light emitting section will be described according to the time chart shown in
When using this technique, the current Is, or the input signal, is received in the first half t0/4 while the latter half 3t0/4 is made “High,” thereby allowing input and output to be performed within one pulse cycle. Reflecting the input in the output within one pulse cycle simultaneously is defined as full-duplex communication, which is a technique that allows the input signal and the output signal to be carried within the period of the same pulse. When full-duplex communication is used, by setting the same address for the light emission side of the transmission sensor terminal 11 and the light reception side of the transmission sensor terminal 11 shown in
In the figure, an example is shown in which the connector 35 connecting the light emitting/receiving section 30 and the signal line section 34 is connected to the power line of the bus line through the T-branch connector 45 in order to obtain the power source of the data-setting-circuit-equipped console 26. Accordingly, the console 26 does not need a power source such as a battery power source, and as such, it achieves battery management, downsizing and weight reduction with respect to the shape used.
When the power source of the data-setting-circuit-equipped console 26 is connected to a signal transmission line or a power line in order to receive a power supply, a secondary battery is eliminated, achieving further both weight reduction and downsizing of the console 26.
In the example shown in the figure, the data-setting-circuit-equipped console 26 is connected to the branch connector 45 through the signal line section 34 on the connector 35 of the console. Following that, the number of the control/monitor terminal device of which the address is set is input into the console in advance. Each time the address of the control/monitor terminal device is set, the counter number of the input value of the number of control/monitor terminal device is decreased. When the counter number reaches “0”, the completion of address setting is recognized, and a program is run to terminate the address writing operation.
For the control/monitor terminal device in which, by using the reflective tap, the light transmission window 33 of the control/monitor terminal device is sealed by the reflective tape in order to receive the reflection of the light emission signal at all times, the address is set to be a specific address value at its initial setting.
For example, for the control/monitor terminal device of which the address is not set, the address, when the address value is a 4-bit address, is set to be 1111. It is therefore recognized that the address is not set for the control/monitor terminal device of which the address is 1111.
Following that, the state of the light transmission window 33 is read, and if own light transmission signal is received by the reflective tape at all times, it is determined that the state is not in the address writing state. Next, when the seal of the reflective tape is removed at the time of address setting, the address setting signal sent from the console through the transmission signal line is detected to write the address value following the address setting signal which is written in the address storage area as own address. The control/monitor terminal device of which own address has been written in the address storage area sends a write completion signal to the console. The console which has received the write completion signal sends the next address value setting signal to the transmission signal line and waits for the timing at which the seal of the reflective tape of the light transmission window 33 of the control/monitor terminal device of which the address is not set is removed. Through this series of operations, the address setting of the control/monitor terminal is performed until the counter value of the console reaches “0” (not shown).
The present invention provides, easily and at low cost, an oil-resistant structure for the address setting section of an electronic control device installed in an environment which requires oil resistance such as a machine assembly factory and an electronic control device including such can be widely applied in an oil-resistant or oil-mist environment.
According to the present invention, a low-cost, space-saving, and downsized device can be achieved and the address setting and initial setting of a control/monitor terminal can be performed reliably in an oil-polluted, humid environment.
The present disclosure relates to subject matters contained in Japanese Patent Application No. 2008-173976 (filed on Jun. 6, 2008), which is expressly incorporated herein, by reference, in its entirety.
Number | Date | Country | Kind |
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2008-173976 | Jun 2008 | JP | national |