JP2000010902A - Daisy chain connecting device and its address setting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a daisy chain connecting device which can easily set an address and also to provide an address setting method for the connecting device. SOLUTION: A host device 1 sends an address setting command having the address data to a module 2 of a first stage. A CPU 7 of the module 2 sets an address to its own module 2 according to the received address data 'AD1' and stores the address in a memory 8. Then the CPU 7 produces the address for a module of the next stage based on the address setting rule arranged among all modules and also based on its own module address and sends an address setting command having address data 'AD2' accordant with the produced address to a module 3 of a 2nd stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a daisy chain connection device used for a display for displaying characters, figures, and the like.
Further, the present invention relates to a method of setting an address in a daisy chain connection device.

[0002]

2. Description of the Related Art FIG. 5 is an explanatory diagram of a display system using a plurality of display modules. FIG. 5A illustrates a case where one display is configured using a plurality of display modules, and FIG. 5B illustrates a case where each of the plurality of display modules configures one display. FIG. 1
Denotes a host device, 51 and 53 to 55 denote display devices, and 51 a to 5.
1e, 53a to 55a are display modules, and 52 is a connection cable. The host device 1 has a built-in CPU (Central Processing Unit), and inputs display data from a keyboard or wirelessly inputs display data from a center device (not shown) to display modules 51a to 51e, 53a to 53e.
55a. The indicators 51 and 53 to 55 are used as a message display board for displaying interest rates and exchange rates in a bank, and displaying a train departure time in a station yard, for example.

In FIG. 5A, a display 51 is connected to a host device 1 and includes a plurality of display modules 51a to 51a.
1e, and each of the display modules 51a to 51e can receive data from the host device 1 and display independent contents. Display modules 51a to 51
Specific examples of e include, for example, a display device using a fluorescent display tube, a light emitting diode, or the like, or a mechanical drive type display device that changes display characters by rotating a plurality of display plates. The display 51 is connected to the host device 1 by a connection cable 52.
, Each of the display modules 51a to 51e is bus-connected to the host device 1 by a connection cable (not shown).

[0004] In FIG.
4 and 55 are installed in remote places. Indicators 53, 5
4 and 55 are a plurality of display modules 53a to 53a, respectively.
55a. The display modules 53a to 55a are the same as the display modules 51a to 51e in FIG. 5A, are connected to the host device 1 by a bus, receive data from the host device 1, and perform independent display. It can be carried out. Although not shown, a plurality of displays similar to the display 51 shown in FIG. 5A may be installed at a distant place, and all the display modules may be connected to the host device 1. .

FIG. 6 is an explanatory diagram of an interconnection form between a host device and a module. FIG. 6A shows an example of bus connection. In the figure, 61 is a first-stage module, 62 is a second-stage module, and 63 is an n-th module. FIG.
(B) is an example of a daisy chain connection. In the figure, 64
Is the first stage module, 65 is the second stage module, 6
Reference numeral 6 denotes an n-th stage module. The display module in the display system of FIG. 5 is an example of the module shown in FIG. Data is transmitted and received between the host device 1 and the modules at each stage.

In the bus connection shown in FIG. 6A, the host device 1 and all the modules 61 to 63 are directly connected by connection cables. In order to enable data transmission and reception between the host device 1 and a plurality of modules, a dip switch or the like is provided in each of the modules 61 to 63 to set an address.

In the daisy chain connection shown in FIG. 6B, the host device 1 is connected only to the adjacent first-stage module 64, and the first-stage module 64 is further connected to the adjacent second-stage module 65. , And the second-stage module 65 is further connected to an adjacent third-stage module (not shown), and similarly connected to the n-th module 66. An example of such a daisy-chain connection is a SCSI (Small Computer System Interface) for transmitting and receiving data between a personal computer and a peripheral device.
tem Interface). The SCSI transmits data in parallel, and has a plurality of control signal lines in addition to a line for transmitting data. However, the daisy-chain connection itself may be one that serially transmits data, or one that does not have a control signal line.

In the display system shown in FIG. 5, FIG.
By using the daisy chain connection shown in
Since each module functions as a repeater (repeater), the connection cable can be lengthened to extend the transmission distance. FIG. 7 is a block diagram of a module in a daisy chain connection. In the drawings, the same parts as those in FIGS. 5 and 6 are denoted by the same reference numerals, and description thereof is omitted. 4,6,
Reference numerals 9 and 10 are connectors, reference numerals 5 and 11 are serial transceivers, reference numerals 7 and 12 are CPUs, and reference numerals 71 and 72 are address setting switches.

The host device 1 is connected to the host device 1 via a connection cable.
The connector 4 is connected to the connector 4 of the module 64 at the stage, and the connector 4 is connected to the serial transceiver 5. The serial transceiver 5 is connected to the CPU (Central Processing Unit) 7. Such connection enables transmission and reception between the host device 1 and the CPU 7 of the first-stage module 64.

The CPU 7 is connected to the connector 6 via the serial transceiver 5, and the connector 6 is connected to the connector 9 of the second-stage module 65 via a connection cable.
Connected to. Connector 9 is serial transceiver 11
, And the serial transceiver 11 is connected to the CPU 12. With such a connection, the host device 1
2 relayed by the CPU 7 of the first-stage module 64
Transmission and reception with the CPU 12 of the module 65 at the stage are enabled. The connector 10 of the second-stage module 65 is connected to the connector of the subsequent module via a connection cable. In this manner, the host device 1 is relayed by the CPU of the intermediate module to
Transmission and reception between

As described above, when a plurality of modules are daisy-chain connected and the host device 1 transmits data such as display information and control information to each module, a unique address is set for each module. , You need to specify a specific module at this address. Therefore, similarly to the bus connection in FIG. 6A, each module is provided with an address setting switch 71, 72 such as a DIP switch, a Sammi Lu switch (digital switch), or a jumper. Connecting. Host device 1 and module (1) 64,
When the modules (2) 65... Are daisy-chain connected, it is necessary for an operator to switch the address setting switches 71 and 72 to set an address.

However, in the above-described hardware address setting, since an address is individually set for each module in advance, there is a problem that a burden on an operator is large. In addition, it is necessary to provide a switch and a jumper for setting an address in each module, which causes a problem that the cost is increased.

[0013]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has a daisy chain connection device capable of easily setting an address to a plurality of daisy chain connected devices. It is another object of the present invention to provide an address setting method for a daisy chain connection device. It is still another object of the present invention to provide a daisy-chain-connected device that can not only increase the reliability of address setting of a daisy-chain-connected system but also know the total number of devices, and to provide an address setting method for daisy-chain-connected devices Things.

[0014]

A daisy chain connection device according to the present invention is a daisy chain connection device for setting a unique address for each device to a plurality of devices connected in a daisy chain. Means for receiving an address setting command appended with address data, means for setting an address in its own device according to the received address data, and the address to a subsequent device according to the address of the own device Means for creating data; and means for transmitting an address setting command to which the created address data is attached to the subsequent device. The address setting method for a daisy chain connected device according to the present invention is an address setting method for a daisy chain connected device for setting a unique address for each device to a plurality of devices connected in a daisy chain. Receives an address setting command to which address data is attached, sets an address to its own device according to the received address data, and creates the address data for a subsequent device according to the address of the own device. Then, an address setting command to which the created address data is added is transmitted to the subsequent device. Therefore, it is possible to easily set the addresses determined among the plurality of devices in the daisy chain connection.

[0015] In the daisy-chain-connected device of the present invention, furthermore, a means for detecting that the device is not connected at a subsequent stage of the own device, and the device is not connected at a subsequent stage of the own device. Means for sometimes creating final address data according to the address of the own device, means for returning a setting completion signal with the created final address data to the device at the preceding stage, and the device at the subsequent stage When the setting completion signal is received from
Means for returning the setting completion signal to the device at the preceding stage. Further, in the address setting method of the daisy chain connection device of the present invention, further, it is detected that the device is not connected to the subsequent stage of the own device, and the final address is determined according to the address of the own device. Create data, return a setting completion signal with the created final address data attached to the preceding device, and when receiving the setting completion signal from the subsequent device, the setting completion signal Reply to the previous device. Therefore, not only can the reliability of the address setting of the daisy chained system be increased, but also the total number of daisy chained devices can be known.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram of a daisy chain connection device for explaining an embodiment of a daisy chain connection device and an address setting method thereof according to the present invention. In the figure, the same parts as those in FIGS. Reference numeral 2 denotes a first-stage module, and reference numeral 3 denotes a second-stage module. Instead of address setting switches and jumpers, memories 8 and 13 for storing set addresses are provided.
Connected to PU7, PU12.

Addresses are set for each module by a program stored in a memory (not shown) of the memory or hard magnetic disk of the host device 1, the first-stage module 2, the second-stage module 3,... Are stored in the memory 13 and the address of the module 3 in the second stage is stored in the memory 13, respectively. The memories 8 and 13 are electrically erasable and rewritable EEPROMs (Electrically Erasable Prog
A nonvolatile memory such as a rammable read only memory (RAM), a CMOS RAM backed up by a battery, and the like are used. Although not shown in the drawings, the CPUs 7 and 12 perform RA processing in order to execute the processing by the programs.
M is connected. Therefore, the address may be stored in a partial storage area of the RAM. However, if the power supply to the module is cut off, it is necessary to set the address again.

Next, the principle of a method for setting a unique address to each module will be described. A daisy-chain connection is made between the host device 1 and the first-stage module 2, the second-stage module 3,... With a connection cable. Host device 1
From the first module 2 to the address data "A"
The address setting command to which "D1" is added is transmitted.
The CPU 7 of the first-stage module 2 sets an address in its own module according to the received address data “AD1” and stores the address in the memory 8. Next, the CPU 7 responds to the address of its own module in accordance with the address setting rules determined among all the modules.
The address of an adjacent subsequent module is determined. Address data “AD2” corresponding to this address is created,
The address setting command to which the address data “AD2” is added is transmitted to the second-stage module 3 at the subsequent stage. Note that a program that performs processing in accordance with the above-described address setting rules is stored in each module.

In the second-stage module 3, the CPU 1
2 receives an address setting command to which address data “AD2” is added from the first-stage module 2 of the preceding stage. Similarly to the first-stage CPU 7, an address is set in its own module according to the received address data "AD2". Next, the CPU 12 determines an address for a subsequent module according to the address of its own module in accordance with the address setting rules determined among all the modules, and stores the address data “AD3” corresponding to this address. Create the address data "AD
The address setting command to which "3" is added is transmitted to the third module at the subsequent stage. Similarly, an address setting command with address data added is transmitted to the last module, and addresses are set and stored for all modules.

As a result, data can be individually transmitted from the host device 1 to the first-stage module 2, the second-stage module 3,... By specifying an address. Furthermore, if a unique address is set in the host device 1 in advance, data can be individually transmitted from each module to the host device 1.

The above-described address setting rule is a rule for setting a unique address for each of a plurality of modules. As a specific example, the rule is that the address number set for itself is incremented by a predetermined value, for example, one. Alternatively, a rule may be used in which the address number set for itself is decremented by a predetermined value, for example, 1. For example, the host device 1 sets the address number 1 to the first-stage module 2, increments the address number to 2 in the second-stage module 3, and sequentially sets 3, 4, 5,... I do.

In the above description, according to the address setting rule, the address for the adjacent subsequent module is determined according to the address of the own module, and the address data for the subsequent module is created. Instead, the address data corresponding to the address of the own module is transmitted to the subsequent stage, and the subsequent module determines the address for the subsequent module according to the address setting rule according to the address data from the previous stage. You may. In this case, the host device 1
, The address data corresponding to the address of the host device 1 may be transmitted. In any of the above-described methods, a unique address can be set for each module according to an address setting rule decided between a plurality of modules. The address data may be simply the address number itself. However, it is not always necessary to match the address number, and any data may be used as long as there is a one-to-one relationship with the address number.

FIG. 2 is a flowchart for explaining the program processing on the host device side when setting a unique address to each module shown in FIG. FIG. 3 is a flowchart for explaining the program processing on the module side when setting a unique address for each module shown in FIG. FIG. 4 is a sequence diagram for explaining a state in which address data and address setting completion data are transmitted and received between the host device shown in FIG. 1 and each module. With reference to FIGS. 2 to 4, a method of setting a unique address to each module will be specifically described. In this specific example, in addition to the setting of the address, a function of confirming that the address has been set is provided.

[0024] In S21 in FIG. 2, sets the wait time D ₀ of the host device 1, the process proceeds to S22. This D
The value of ₀ is set in consideration of the total number of modules to be predicted and the transmission delay time, time T ₁ , and time T ₂ described below. In S22, the address setting command and the address data AD1 are transmitted, and the process proceeds to S23. S
At 23, it is determined whether or not a setting completion signal has been received. If not, the process proceeds to S24, and if received, the process proceeds to S25. Here, the setting completion signal is a signal indicating that the address setting has been completed for the last module in the daisy chain connection, and address data corresponding to the address number of the last module is added. As shown in FIG. 4, it is generated by the last module 4, and is sequentially relayed and transmitted to the preceding module adjacent to the host and reaches the host device 1.

[0025] In S24, determines whether the waiting time D ₀ which is set in S21 above has elapsed, when not elapsed, the process returns to S23, when the elapsed S
The process proceeds to 26. Although not shown in the figure, the determination of the latency is set to D ₀ in S21 the value of a parameter indicating the wait time, reducing the value to each pass through the iterative loop in S23 from S24, the value in S24 What is necessary is just to determine when becomes negative. In S26, the setting completion signal even after waiting D ₀ is not received, informing the operator that the address setting has failed.

On the other hand, in S25, it is possible to know the last connection module by judging in which module the setting completion signal is generated. That is, the total number of connected modules in the daisy chain can be known. In the specific example shown in FIG.
Is connected platform modules are received setting completion signal "OK4" when waiting D ₀ elapses. It is desirable that the waiting time D ₀ has some allowance.

In FIG. 3, the first-stage module 2 will be described, but the same applies to other modules. In S31, a command and data are received from the host device 1, and the process proceeds to S32. In the case of another module, it receives a command and data from an adjacent module, which is a preceding module on the host side. Although omitted in this flowchart, the process remains at S31 until a command and data are received.

In S32, it is determined whether or not the received command is an address setting command. If the received command is not an address setting command, the process proceeds to S33, and if it is an address setting command, the process proceeds to S34. In S33, each command and data are processed. S34
In, the own address number is set according to the received address data AD1 and stored in the memory 8. S35
In, the address data AD2 corresponding to the incremented address number is created, and the process proceeds to S36. In S36, by setting the waiting time D ₁ S37
Processing proceeds to The waiting time D ₁ is set to be shorter than the waiting time D ₀ of the host device 1 by the time T ₁ + T ₂ . However, the transmission delay time between the host 1 and the first-stage module 2 is ignored.

In S37, the address setting command and the new address data AD2 are transmitted to the second module 3 in the subsequent stage, and the process proceeds to S38. Time T ₁ shown in FIG. 4, from the time of detecting the reception of the address setting command and data by S32, the processing delay time before sending the address setting command and address data in S37. In S38, it is determined whether or not a setting completion signal has been received from the subsequent second-stage module 3. If it has been received, the process proceeds to S41, and if not received, the process proceeds to S39.

In [0030] S39, and determines whether or not the wait time D ₁ that has been set has elapsed in S36, the process returns to S38 when not elapsed, when the elapsed advances the process to S40. In S40, it determines that it is the last module, creates a setting completion signal to which the final address data according to its own unique address is attached, and proceeds to S41.

In step S41, when the processing is directly advanced from step S38, the received setting completion signal is returned to the host device 1 as it is. When the process proceeds from S40, the setting completion signal generated in S40 is returned to the host device 1. In this step S41 in the second and subsequent modules, the relay is performed by returning a setting completion signal to the preceding module. Time T ₂ shown in FIG. 4 is a processing delay time until returning a setting completion signal in S41 from the time of detecting the passage of the waiting time D ₁ at S39. However, as shown in FIG. 4, previously combined such that the time T ₂ the time until it returns a setting completion signal received in S41 from the time of receiving the setting completion signal at S38.

In the example shown in FIG. 4, no module is connected to the subsequent stage of the module 4. Therefore, only the module 4, elapsed wait time D _4, similar to step S40 shown, the process advances to steps in module 4, setting completion signal, labeled by the address data corresponding to the unique address number itself “OK4” is created, and the process proceeds to the step in the module 4 similar to the step S41 in the drawing. By performing the above-described processing by all the modules connected in the daisy chain, an address unique to the system can be set to all the connected modules.

It should be noted that the order of the own module is determined from the own address, and the waiting time D _{1 to} D ₄ of each module is set. That is, the time (T ₁ + T ₂ ) × the number of stages is subtracted from the waiting time D _{0 of the} host device. Therefore, D ₀ is determined so that the waiting time does not become zero in the last module to be predicted. However, the transmission delay time between the host 1 and the first-stage module 2 and between the modules is ignored. Although it is desirable that the waiting time has a margin, it is necessary to increase the margin time as it is closer to the host device 1 in consideration of the accumulation of the module's margin time in the intermediate stage.

In the above description, when the reception of the address setting command and data is detected in S32, the time T
After _one elapse, the address setting command and data were unconditionally transmitted to the subsequent module. Instead, after completing the daisy-chain connection and starting the power supply, each module automatically outputs a transmission request signal to the host device 1 or a preceding module adjacent to the host device 1. Keep it.

In each module, it is determined whether or not a transmission request signal has been received via a connection connector to a subsequent stage. If the transmission request signal has not been received even after a predetermined time has elapsed, the module is connected to the subsequent stage. If not, it detects itself as the last module. Then, transmission of the address setting command and the address data to the subsequent stage is stopped, and a setting completion signal is returned. In this case, in each module, the waiting times D _{1 to} D ₄ are not used to determine whether or not there is a module at a subsequent stage. Accordingly, the host device 1 only, total module predicted, it determines the predetermined waiting time corresponding to the time T _1, T _2. It is determined whether a setting completion signal is received within this predetermined waiting time.

In the above description, a function of returning a setting completion signal to the host device 1 is provided. However, if it is used in an environment where transmission errors do not occur and the operator knows how many modules are daisy-chained, there is no need to return the setting completion signal. Good. The method of returning the setting completion signal to the host device 1 is not limited to the above-described example, and may be performed by another method. For example, when receiving an address setting command and address data, each module creates a setting completion signal with address data according to its own address number, and generates a setting completion signal adjacent to the host device 1 or
Each module sends back the setting completion signal received from the subsequent module located on the opposite side of the host device 1 to the host device 1 as it is. You may make it relay.

In the above description, the address is set by the program processing by the CPU, but this address setting can be realized by hardware logic. Also in this case, no switch or jumper for address setting is required, and the operator does not need to perform setting work for each module individually. The above-described address setting method is preferably used for address setting of a display system that transmits display data to a plurality of display modules from a host device. However, the present invention can also be used for a system that transmits data from the module side to the host device side, or a system that transmits and receives data bidirectionally.

[0038]

As is apparent from the above description, according to the present invention, a device daisy chain-connected without an operator performing a hardware setting operation such as an address setting switch or a jumper can be used. The effect is that the address can be set automatically. Therefore, it is possible to reduce the number of expensive mechanical parts, and to eliminate an erroneous address setting by an operator. It is possible to automatically set the address for the replaced device without changing anything in hardware, not only when daisy-chaining when installing the device, but also when replacing the device during use effective.

Returning the setting completion signal not only increases the reliability of the daisy-chain-connected system, but also has the effect of knowing the total number of daisy-chain-connected devices.

[Brief description of the drawings]

FIG. 1 is a daisy chain connection device of the present invention, and
FIG. 2 is a block diagram of a daisy-chain connection device for explaining an embodiment of the address setting method.

FIG. 2 is a flowchart for explaining a program process on a host device side when a unique address is set to each module shown in FIG. 1;

FIG. 3 is a flowchart for explaining a program process on the module side when setting a unique address for each module shown in FIG. 1;

FIG. 4 is a sequence diagram for explaining a state in which address data and address setting completion data are transmitted and received between the host device shown in FIG. 1 and each module.

FIG. 5 is an explanatory diagram of a display system using a plurality of display modules.

FIG. 6 is an explanatory diagram of an interconnection mode between a host device and a module.

FIG. 7 is a block diagram of a module in a daisy chain connection.

[Explanation of symbols]

1 host device, 2nd stage module, 3rd stage module, 4, 6, 9, 10 connector, 5, 11
Serial transceiver, 7,12 CPU, 71,7
2 address setting switch, 51, 53-55 display, 51a-51e, 53a-55a display module, 52 connection cable

Claims (4)

[Claims] 1. A daisy-chain-connected device for setting a unique address for each device to a plurality of daisy-chain-connected devices, and means for receiving an address setting command added with address data from a preceding device. Means for setting an address in its own device according to the received address data,
A daisy chain comprising: means for creating the address data for a subsequent device in accordance with the address of the own device; and means for transmitting an address setting command to which the created address data is attached to the subsequent device. Connected equipment. 2. A means for detecting that the device is not connected to a stage subsequent to the own device, and means for detecting the address of the device when the device is not connected to a stage subsequent to the own device. Means for generating final address data in response thereto, means for returning a setting completion signal to which the generated final address data is attached to the preceding device, and when the setting completion signal is received from the subsequent device. ,
2. The daisy-chain connection device according to claim 1, further comprising: means for returning the setting completion signal to the preceding device. 3. An address setting method for a daisy chain connected device for setting a unique address to each device for a plurality of devices connected in a daisy chain, wherein an address setting command to which address data is added from a preceding device is provided. Receiving, setting an address in its own device according to the received address data, creating the address data for a subsequent device according to the address of the own device, the created address data is attached Transmitting an address setting command to the subsequent device. 4. Detecting that the device is not connected to a stage subsequent to the own device, creating final address data according to the address of the own device, and generating the final address data. Attached setting completion signal is returned to the device at the preceding stage, and when the setting completion signal is received from the device at the subsequent stage, the setting completion signal is returned to the device at the preceding stage. 3
The method for setting the address of the daisy-chain connection device described in 1.