JP4068079B2 - Data transmission method - Google Patents

Description

  The present invention relates to a data transmission method for controlling a plurality of controlled devices connected to one control device.

  Conventionally, when a plurality of controlled devices (expansion devices) are connected to a single control device (host device) to control these controlled devices, the number of control signals increases as the number of controlled devices increases. In order to improve the inconvenience, there is a proposal to connect devices by serial transmission (for example, see Patent Document 1). In this method, a plurality of extension devices are all connected in parallel and connected to the host device through a fixed number of signal lines. Then, the host device sends a clock signal to the extension device, and in synchronization with the clock signal, sends a selection bit indicating the type of the extension device and transmission data as a serial signal in units of a fixed number of bits. The transmission data from the expansion device side is read. On the other hand, when each extension device receives data of a certain number of bits from the host device, it collates the selection bit in the data with the bit data of the selection code set in advance for each unit, If they match, the transmission data in the fixed number of data is read, and in parallel with the reading operation, the transmission data to be transmitted is sent as a serial signal in units of a fixed bit. As a result, the host device and each expansion device exchange transmission data using serial signals, so the number of signal lines between them can be reduced, and multiple expansion devices are connected in parallel to the signal lines. Even if the number increases, it is not necessary to increase the number of signal lines.

JP-A-5-46548

  In the case of device connection by performing serial transmission as described above, since the identification code (number of bits) and the data frame are determined by setting the upper limit of the selected device in advance, there is an upper limit on the number of additional devices. Therefore, when adding a new controlled device, there is a limit on the number of devices that can be added, so the data length necessary for the preset data frame will not fit, and it will be connected to the existing controlled device. There arises a problem that a change is required depending on conditions.

  The present invention has been made to solve the above-described problems, and removes restrictions on the number of connected units and the data length of the data frame and serially transmits control data to reduce the number of signal lines connected between controlled devices. The purpose is to obtain a data transmission system that does not increase.

  The data transmission method according to the present invention forms a control loop in which transmission data output from a control device returns through a plurality of controlled devices, and the transmission data is a reference for operation of the control device and the plurality of controlled devices. Represents the clock signal, the control data consisting of each frame of setting data and status data expressed in bit strings corresponding to a plurality of controlled devices, and the location where setting data on the control data is fetched and the location where status data is inserted Each of the plurality of controlled devices has a frame delimiter signal indicating its own position when the strobe is in a state where the setting data is captured. When detected, the setting data of the corresponding frame is taken from the control data, and the predetermined setting is made. Upon detecting a frame delimiter signal indicating the position of the self when in the state shown the insertion point, and transmit toward the control device via the inserted control loop its own state data to the corresponding frame on the control data.

  According to the present invention, the number of controlled devices connected can be increased or decreased by simply changing the value of the number of stages N on the transmission data on the software, so there is no need to remake the hardware on the control device side. There is no need to add and route the devices individually, and there is an effect that controlled devices can be added almost unlimitedly.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a data transmission system according to the first to fifth embodiments of the present invention. This configuration exemplifies a data transmission method in which transmission data is converted into an optical signal and transmitted using an optical fiber to control the controlled devices 2 ₁ to 2 _N. Can be applied similarly.
Controller 1, the controlled device 2 ₁ to 2 _N, for example, various switches switch, filter selection, to perform the control such as parameter switching, and transmit data to obtain the status of the controlled device 2 ₁ to 2 _N Means for transmitting and receiving. Each of the controlled devices 2 _{1 to} 2 _N performs switching of a passband filter of a signal received using, for example, an antenna element, but this example does not specify the invention. The controlled device 5 in the controlled devices 2 _{1 to} 2 _N represents a receiver in this example. The I / F conversion unit 3 converts transmission data input as an optical signal into an electrical signal, converts the transmission data electrical signal indicating the setting state and status of the controlled device 5 into an optical signal, and outputs the optical signal to the transmission path And means for converting serial data into parallel data to be supplied to the controlled device 5 and converting parallel data from the controlled device 5 into serial data. being called.

Four types of signal lines are connected in series from the control device 1 so as to go around the controlled devices 2 ₁ to 2 _N , and the control data loops and finally returns to the control device 1 side. Have. Transmission data 4a from the control unit 1, 4b is composed of a plurality of signals transmitted serially, the required controlled device 2 ₁ to 2 _N is incorporated in the controlled device 2 ₁ to 2 _N in the desired number It has a role of setting the status and transmitting the status of the controlled devices 2 ₁ to 2 _N to the control device 1. The configuration of the transmission data 4a and 4b is shown in the time chart of FIG. 2 for explaining the operation according to the first embodiment. Here, the transmission data 4a output from the control device 1, the transmission data 4b returned from the control loop, the data 5a input to the I / F converter 3, and the data output to the transmission path by the I / F converter 3 5b is shown.

The transmission data 4a and 4b are the clock signal CLK, which is the reference for the operation of the control device 1 and the controlled devices 2 ₁ to 2 _N , the control data DT represented by the bit string, and the location and state of the setting data on the control data DT It is composed of at least four lines: a strobe STB indicating a data insertion point and a frame delimiter signal FRM indicating a frame delimiter on the control data DT. Here, the control data DT includes a frame and state data (state 1, state 2,..., State N) of setting data (setting 1, setting 2,..., Setting N) corresponding to the controlled devices 2 ₁ to 2 _N. It consists of frames. The number of bits of each setting data is represented by k, and the number of bits of each state data is represented by m. The strobe STB has an “H” state and an “L” state. The “H” state represents a period during which the controlled devices 2 ₁ to 2 _N can fetch setting data corresponding to itself from the control data DT. This state represents a period during which the state data can be inserted into the control data DT.

Next, a general transmission operation will be described.
When the transmission data 4a is output from the control device 1, each of the controlled devices 2 ₁ to 2 _N counts the frame delimiter signal FRM when the strobe STB becomes “H”. When the frame delimiter signal FRM indicating its own position is received, setting data (corresponding data of setting 1, setting 2... Setting N) of the corresponding frame on the control data DT is fetched. When setting data exists in the corresponding frame, the fetched setting data is converted into parallel data and sent to the receiver (controlled unit) 5. The controlled unit 5 performs a predetermined setting according to the contents. Thereafter, when the strobe STB is in the “L” state, the controlled devices 2 ₁ to 2 _N count the frame delimiter signal FRM, and when the frame delimiter signal FRM indicating its own position comes, the corresponding frame on the control data DT The own state data is inserted into (the corresponding frame in state 1, state 2... State N). The transmission data 4b output by sequentially performing these operations in the controlled devices 2 ₁ to 2 _N is transmitted toward the control device 1.
Note that noise reduction may be performed by stopping the clock signal CLK except when the setting operation is performed.

Next, a case where the controlled devices are increased or decreased will be described.
For example, when the controlled device increases by one stage to N + 1 stages, the number of setting data and status data frames constituting the control data DT is increased to N + 1. The length of the strobe STB is also increased by that amount, and the number of frame delimiter signals FRM is also increased. On the other hand, when the controlled device is reduced to N−1 stages, each frame of setting data and status data of the control data DT is reduced to N−1, and the length of the strobe STB is also shortened by that amount. The number of signals FRM is also reduced.

As described above, according to the first embodiment, the increase / decrease in the number of connected controlled devices is determined by the number of frames N of the control data DT constituting the transmission data, the length of the corresponding strobe STB, and the frame delimiter signal FRM. Since it is possible to respond by changing the number, the control device only needs to make a simple software change, there is no need to change the hardware, and there is no need to add and route wiring individually The effect is obtained. An effect can be obtained in which controlled devices can be added almost unlimitedly without adding an identification bit or the like to existing controlled devices.
In the above operation example, the connection order of controlled devices on the control loop has been described so as to match the setting data sending order. However, the controlled device connection order is not necessarily the setting data sending order. The present invention can be applied without matching. That is, if the identification position of the frame delimiter signal FRM is determined in advance in each controlled device, the sending order is not limited. Therefore, it is possible to obtain an effect that the controlled devices can be increased or decreased without restricting the physical arrangement.

Embodiment 2. FIG.
FIG. 3 is a time chart for explaining transmission data according to the second embodiment.
FIG. 3A shows the case of the first embodiment. The frame length of the control data constituting the transmission data (setting 1, setting 2... Bit number k of setting N and state 1, state 2) ... corresponds to the number of bits m in state N). FIG. 3B shows an example of the second embodiment. The data frame length is not set to a fixed length, but is set to a value as required (all may be different or some may have the same value). For example, the setting data frame is set to a unique value such as the number of bits k1, k2,... Kn, and the state data frame is set to m1, m2,.
When the controlled devices 2 _{1 to} 2 _N are not the same type, the data amount representing the setting or state may be different. Therefore, in such a case, the control device can cope with this without changing the hardware by making it possible to select and set the frame length of at least one of the setting data and the status data as in the second embodiment. .

Embodiment 3 FIG.
FIG. 4 is a time chart of transmission data according to the third embodiment.
In this figure, in the control data DT, the valid / invalid flag is set to “valid” for the setting data “setting 2” (and “state 2”), and the valid / invalid flag is set to “other” for the other setting data. This shows a case where “invalid” is set. In this case, since e.g. effective to "set 1" / invalid flag is "invalid", but the corresponding controlled device 2 _first set is not executed (overwritten), enable / disable flag is "valid" there "set 2" corresponding controlled device 2 _second setting is executed (overwritten). If no valid / invalid flag is provided in the control data DT, even if there is no change, if all settings are not sent one by one each time, the previous settings will be cleared, resulting in a lot of waste in transmission control. Become. The set state is transmitted to the control device 1 as state 2.
Accordingly, by providing the enable / disable flag in the control data DT, if you want to update the configuration only the controlled device 2 ₂ without transmitting all of the data of the controlled device 2 _{2 to} the controlled device 2 _N If the flag is set to “valid” only at the location to be updated and the setting data is transmitted, it becomes possible to control only a predetermined controlled device.

Embodiment 4 FIG.
FIG. 5 is a time chart of transmission data according to the fourth embodiment.
In the first to third embodiments, when the strobe STB is “L”, the control data DT transmits the status data of the output of the controlled devices 2 ₁ to 2 _{N. In} the fourth embodiment, the status data is transmitted. I do not do it. That is, here, the control data DT does not have a state data frame, but performs only one-side communication of setting data for controlling the controlled devices 2 ₁ to 2 _N. This corresponds to the case where only the setting of the controlled device is targeted.
Further, when the predetermined plurality of controlled devices ₂ 1 to 2 _N, for example the same set from the second stage to the instrument ₂ 2 21 to ₂₄ of the fourth-stage "Set 2" performed, the controlled device ₂ 2-2 ₄ are set in advance so as to detect the frame delimiter signal FRM having the same number of stages, that is, the second signal. Then, since all the predetermined plural controlled devices fetch the setting data “setting 2”, the same setting can be performed. When there are many controlled devices that are controlled by one-way communication and target the same setting, the controlled devices can be operated in parallel with respect to the control data DT in this way, so the configuration of transmission data on the control device side The setting can be simplified.
Further, in addition to this case, an identification bit for identifying controlled devices within the same number of stages is provided in a frame of setting data. For example, if the setting of the identification bit in the frame of the setting data “setting 2” is “0”, all these three controlled devices capture the setting data “setting 2”, but the setting of the identification bit is If the it was the "4", only the controlled apparatus 2 ₄ of these three is possible to control such loading the preset data "setting 2". Therefore, the same number of frame setting devices can be set collectively or individually as necessary.

Embodiment 5. FIG.
FIG. 6 is a time chart of transmission data according to the fifth embodiment.
In the first embodiment, the setting data frame capturing operation and the status data frame inserting operation are performed by counting the frame delimiter signal FRM. However, in the fifth embodiment, a signal that does not use the frame delimiter signal FRM. It is configured. Here, a frame of setting data and status data is recognized using a time slot (signal time delimiter) instead of the frame delimiter signal FRM. As a condition for this, the lengths of the setting data and the state data are set to a constant or integer multiple relationship. Time slot detection is performed by counting the clock signal CLK from the rising edge of the strobe STB in the controlled devices 2 ₁ to 2 _N.
According to the fifth embodiment, the signal lines of the frame delimiter signal FRM can be reduced from the case of the first embodiment.

Embodiment 6 FIG.
FIG. 7 is a block diagram showing a configuration of a data transmission system according to the sixth embodiment.
Here, compared with the configuration of FIG. 1, the route switching unit 7 is provided, and the controlled device can be configured to change the control loop configuration via the route switching unit 7.
In this case, the first setting data frame in the control data DT is assigned to the route switching operation. The route switching unit 7 performs the same operation as the I / F conversion unit 3 of the controlled device. When receiving the setting data of itself, the route switching unit 7 controls the group of the controlled devices 20 _{1 to} 20 _N according to the contents thereof. Set whether to add or remove. When added to the control loop, a group of other controlled devices 21 _{1 to} 21 _M is formed with the control loop, and transmission data is sent to perform the same operation as described in the first embodiment. On the other hand, when the setting is made in the route switching unit 7 excluding the group of the controlled devices 20 _{1 to} 20 _N , the transmission data is only sent from the route switching unit 7 directly to the group of the controlled devices 21 _{1 to} 21 _M. It is sent to the control loop, and settings for these controlled devices 21 _{1 to} 21 _M are sequentially performed.
Therefore, by adopting the configuration as in the sixth embodiment, it is possible to organize by dividing into controlled devices that are always controlled and controlled devices that are controlled as necessary. This makes it possible to deal with a case where there is no time to control the total number.

FIG. 1 is a block diagram showing the configuration of a data transmission system according to the first to fifth embodiments of the present invention. It is a time chart of the transmission data explaining the operation | movement which concerns on Embodiment 1 of this invention. It is a time chart of the transmission data which concerns on Embodiment 2 of this invention. It is a time chart of the transmission data which concerns on Embodiment 3 of this invention. It is a time chart of the transmission data which concerns on Embodiment 4 of this invention. It is a time chart of the transmission data which concerns on Embodiment 5 of this invention. It is a block diagram which shows the structure of the data transmission system by Embodiment 6 of this invention.

Explanation of symbols

1 control device, 2 _{1 to} 2 _N , 20 _{1 to} 20 _N , 21 _{1 to} 21 _M controlled device, 3 I / F conversion unit, 4a and 4b transmission data, 5 receiver (controlled unit), 7 routes Switching unit, DT control data, CLK clock signal, FRM frame delimiter signal, STB strobe.

Claims (8)

The transmission data output from the control device forms a control loop that makes a round of multiple controlled devices,
The transmission data is
A clock signal serving as a reference for the operation of the control device and the plurality of controlled devices;
Control data consisting of each frame of setting data and status data represented by a bit string corresponding to the plurality of controlled devices,
A strobe that represents the location where setting data on the control data is captured and the location where status data is inserted;
It has a frame delimiter signal indicating the frame delimiter on the control data,
When each of the plurality of controlled devices detects a frame delimiter signal indicating its own position when the strobe indicates a setting data capture location, it captures the setting data of the corresponding frame from the control data and performs a predetermined setting. And then detecting the frame delimiter signal indicating its own position when the strobe is in the state indicating the insertion position of the state data, inserting its own state data into the corresponding frame on the control data, and passing through the control loop A data transmission method characterized by transmitting to a control device.   2. The data transmission system according to claim 1, wherein the frame length of at least one of the setting data and the status data is set with the number of bits determined corresponding to each controlled device.   A valid / invalid flag is provided in the control data, and the corresponding controlled device fetches the setting data and performs the requested setting according to the designation of the valid / invalid flag. 1. The data transmission method according to 1.   2. The data transmission system according to claim 1, wherein the control data does not have a status data frame.   The predetermined plurality of controlled devices are set in advance to detect the same number of frame delimiter signals, so that the predetermined plurality of devices capture the same setting data. Item 5. The data transmission method according to Item 4.   In the setting data, an identification bit for identifying controlled devices within the same number of stages is provided in the frame, and the controlled device within the same number of stages fetches the setting data according to the specification by the identification bits and is requested. 6. The data transmission system according to claim 5, wherein setting is performed.   Set the length of setting data and status data to a fixed or integer multiple, and detect the time slot by counting the clock signal instead of the frame delimiter signal and recognize the frame of setting data and status data The data transmission method according to claim 1, wherein the data transmission method is used.   A plurality of controlled devices are divided into at least two groups, and a route switching unit is provided that performs route switching to add or remove the other group in a control loop including one group. 2. The data transmission system according to claim 1, wherein the setting of the route switching operation is assigned to a frame of setting data.

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