JP2022118613A - Device and ID determination method - Google Patents

Abstract

To provide a technology for facilitating ID assignment to a device to be connected to a serial communication network.SOLUTION: According to an embodiment, a device connectable to a serial communication network includes a generation part, an acquisition part, and a determination part. The generation part generates and outputs a response request to an another device connected to the serial communication network by using an ID usable in the serial communication network. The acquisition part acquires information on an assignment state of the usable ID in the serial communication network on the basis of a response from the other device to the response request. The determination part determines an ID to be assigned to an own device on the basis of the information on the assignment state.SELECTED DRAWING: Figure 4

Description

Embodiments of the present invention relate to devices and ID determination methods.

A daisy chain is known as one of methods for connecting a plurality of devices. For example, when one controller is intended to control a plurality of peripheral devices, a daisy chain is formed by multi-drop connecting the peripheral devices to the controller via a half-duplex serial communication path. One example is an application in which a single controller collectively controls a plurality of peripheral devices or substrates used in an inkjet printer. In such applications, mounting space is often limited due to the miniaturization of devices or substrates. For this reason, a differential interface conforming to a serial communication standard such as RS485, which is less susceptible to external noise, is often used.

Here, when one controller (master device) transmits a command to a peripheral device to be controlled (slave device), a unique ID (identification/identifier) assigned to each slave device is used as the destination of the command. must be specified. Generally, in order to assign a unique ID to a slave device, it is necessary to prepare a dedicated communication path in addition to a command communication path conforming to a serial communication standard such as RS485 and write the ID to the memory of the slave device.

After installing a large number of slave devices, it is extremely troublesome to write an ID to each slave device via a dedicated communication path. On the other hand, if the IDs are written individually before installation of each slave device, the user or the like needs to manage the ID of each slave device, and additional costs such as the task of attaching an identification sticker are incurred.

JP-A-2002-124957

A problem to be solved by the embodiments is to provide a technique for facilitating ID assignment to devices connected to a serial communication network.

According to an embodiment, a device connectable to a serial communication network comprises a generator, an acquirer and a determiner. The generator uses an ID that can be used in the serial communication network to generate and output a response request to another device connected to the serial communication network. The acquisition unit acquires information about the assignment status of the usable IDs in the serial communication network based on the response from the other device to the response request. The decision unit decides an ID to be assigned to the own device based on the information about the assignment status.

FIG. 1 is a diagram illustrating an example of a system including devices according to one embodiment. FIG. 2 is a diagram illustrating an example of the configuration of a device according to an embodiment; FIG. 3 is a diagram illustrating an example of a functional configuration of a device according to one embodiment; FIG. 4 is a flowchart illustrating an example operation of a device according to one embodiment. FIG. 5 is a diagram illustrating an example of commands sent and received by a device according to one embodiment. FIG. 6 is a diagram illustrating a first example of an ID determination method process according to an embodiment. FIG. 7 is a diagram illustrating a second example of the process of the ID determination method according to one embodiment. FIG. 8 is a diagram illustrating a third example of an ID determination method process according to an embodiment. FIG. 9 is a side view for explaining an outline of an inkjet printer to which one embodiment can be applied. FIG. 10 is a schematic diagram for explaining the configuration of the liquid ejection head and the liquid circulation device of the liquid ejection device in the inkjet printer of FIG. FIG. 11 is a block diagram showing the essential circuit configuration of the inkjet control device in the inkjet printer of FIG.

An embodiment will be described below with reference to the drawings. Elements that are the same as or similar to elements that have already been explained are denoted by the same or similar reference numerals, and overlapping explanations are basically omitted. For example, when there are multiple identical or similar elements, common reference numerals may be used to describe each element without distinction.

[One embodiment]
(Constitution)
(1) System FIG. 1 is a diagram illustrating an example of a system 1000 including devices according to one embodiment. This system 1000 includes one master device 300 and N slave devices 101, 102, 103, 104, . The slave device 100 is multi-drop connected to the master device 300 via a half-duplex serial communication path CP. System 1000 can also be referred to as a communication network. A device according to one embodiment is implemented as a slave device 100 .

The master device 300 transmits a command (control signal) to the slave device 100 to control the operation of the slave device 100 or grasp the state of the slave device 100 based on the response from the slave device 100 . Master device 300 may be configured by, for example, a personal computer, a PLC (Programmable Logic Controller), an IoT gateway, or the like. The master device 300 can also be called a master device.

The slave device 100 receives commands from the master device 300 and acts on the received commands or sends responses to the master device 300 . The slave device 100 can also be called a slave device. The slave device 100 is, for example, an ink circulation device connected to each ink jet head of an ink circulation type printer, and a pump, heater, or the like connected to the ink circulation device based on commands received from a controller as the master device 300. can be controlled. Such an ink circulation device will be described below.

In one embodiment, slave device 100 is configured to be operable in multiple operating modes including a normal mode (first operating mode) and a pseudo-master mode (second operating mode). In normal mode, slave device 100 operates as a slave device. In the pseudo-master mode, the slave device 100 acts as a pseudo-master device, scans other slave devices 100 hanging on the half-duplex serial communication bus, and obtains information on the status of ID assignment in the system 1000. , determines the ID to be assigned to its own device. Here, scanning means transmitting a response request to another slave device 100 using an ID that can be used within the system 1000, and determining whether or not there is a response to the response request. Pseudo-master mode operation, including scanning, is also described in detail below.

When performing half-duplex serial communication in the system 1000 as shown in FIG. Communication is established. Since it is a one-to-many communication method, each slave device 100 is assigned a unique ID, and the master device 300 adds the ID (destination ID) of the destination slave device 100 to the command to be transmitted, thereby determining the destination of the command. specify. Therefore, it is necessary to manage IDs within the system 1000 so that they do not overlap.

In FIG. 1, "ID=1" is assigned to the master device 300, "ID=2" is assigned to the first slave device 101, "ID=3" is assigned to the second slave device 102, and "ID=3" is assigned to the third slave device 103. “ID=4”, . . . “ID=N+1” is assigned to the N-th slave device 104 . The master device 300 can designate each slave device 100 as a command destination by using ID=2, 3, . . . N+1.

Note that an ID does not necessarily need to be assigned to the master device 300 if command communication is possible. Since it assumes that one master device 300 is connected to the half-duplex serial communication bus, the ID of the master device 300 may not be necessary in the command format received by the master device 300 side. It is from If no ID is assigned to the master device 300, the first slave device 101 has "ID=1", the second slave device 102 has "ID=2", . N" is assigned.

When the master device 300 transmits a command, the command is relayed among the slave devices 100 in turn and received by all the slave devices 100 . The slave device 100 determines whether the received command is addressed to itself based on the unique ID. In half-duplex serial communication, the master device 300 temporarily disables the transmission function after the transmission is completed, enables the reception function, and waits for reception of a response from the slave device 100 . In this way, the slave device 100 normally does not initiate transmission autonomously, and takes action only when it receives a command addressed to itself.

(2) Slave Device FIG. 2 is a diagram showing an example of the configuration of the slave device 100 according to one embodiment.
The slave device 100 includes an MCU (Micro Controller Unit) 110 , a nonvolatile memory 120 , an RS485 transceiver block 130 , a switch 140 and a resistor 150 . MCU 110, nonvolatile memory 120, RS485 transceiver block 130, switch 140 and resistor 150 are connected to each other via a bus or the like.

The MCU 110 is an example of a processor that centrally controls the operation of the slave device 100 . The MCU 110 transmits and receives signals to and from the RS485 transceiver block 130 via the data reception terminal rxd, the data transmission terminal txd, and the chip select terminal select. MCU 110 may include on-board memory such as RAM. The MCU 110 implements various functions described later by executing a predetermined program (firmware, etc.). Some of the functions implemented by MCU 110 may be implemented by hardware circuits. In this case, MCU 110 may control functions performed by hardware circuits.

The nonvolatile memory 120 is, for example, SPI-ROM, EEPROM (registered trademark), FLASH, etc., and is a storage medium for storing programs and data for implementing various functions of the slave device 100 . Non-volatile memory 120 may include non-rewritable non-volatile memory and re-writable non-volatile memory. Non-volatile memory 120 may be implemented as a built-in non-volatile memory section of MCU 110 . In one embodiment, the non-volatile memory 120 is pre-written with programs and system reserved parameters necessary for the operation of the slave device 100 . The system reservation parameters are reservation parameters related to the system 1000, and include the ID assigned to the slave device 100 and the maximum number N of slave devices 100 connectable to the master device 300 (hereinafter also referred to as "maximum number N of connections"). (eg, “N=10”) and . In the shipment state, each slave device 100 can be set with a default ID (for example, “ID=2”). System reservation parameters may also include the ID of master device 300 .

The RS485 transceiver block 130 includes a transmission circuit, a reception circuit, and cable terminals, and communicates with the master device 300 and other slave devices 100 via a half-duplex serial communication path CP using a cable conforming to the RS485 standard. send and receive signals between In one embodiment, a micro-USB cable with an easily connectable geometry is used as the half-duplex serial communication path CP. However, this is only an example, and communication circuits using other standards may be used.

The switch 140 is, for example, a mechanical switch such as a tactile switch, and is connected between the MCU 110 and GND. A resistor 150 is a so-called pull-up resistor and is connected between the MCU 110 and a voltage source (not shown). For example, when the switch 140 is open (OFF), a HIGH signal is input to the MCU 110 from the voltage source via the resistor 150, and when the switch 140 is pressed by a user or the like (ON), a LOW signal is output to the MCU 110. is entered.

In one embodiment, the operation mode of the slave device 100 can be set according to whether the switch 140 is ON or OFF when the slave device 100 is activated (for example, by pressing an activation button (not shown)). When the slave device 100 is activated with the switch 140 in the OFF state, the MCU 110 receives the input of the HIGH signal, reads out the first program stored in the nonvolatile memory 120, and enters the normal operation mode (“normal mode”). ). On the other hand, when the slave device 100 is activated while the switch 140 is ON, such as when the slave device 100 is activated while pressing the switch 140, the MCU 110 receives the input of the LOW signal and stores the signal in the nonvolatile memory 120. It reads out the second program and operates in a "pseudo master mode" to be described later. That is, the slave device 100 can switch the operation mode in response to a user's operation via the switch 140 . The switch 140 can be configured so as not to be inconvenient when installing the slave device 100 and not to be inadvertently pressed. The switch 140 is not limited to a mechanical switch, and may be replaced by a switch using a non-contact medium such as an NFC (Near Field Communication) card, or an optical switch using a photosensitive sensor. good.

FIG. 3 is a diagram showing an example of the functional configuration of the slave device 100 according to one embodiment.
The slave device 100 includes a control section 111 , a storage section 121 and an interface section 131 .

The interface unit 131 has a function of passing a signal received from the outside to the control unit 111 and outputting a signal received from the control unit 111 to the outside. The interface unit 131 is implemented by the above-described RS485 transceiver block 130, switch 140, or the like. The interface section 131 can include a receiver section 132 , a transmitter section 133 , an input section 134 and an output section 135 . The receiving section 132 is implemented by, for example, a receiving circuit of the RS485 transceiver block 130 and has a function of receiving signals from the master device 300 or other slave devices 100 . The transmission unit 133 is implemented by, for example, the transmission circuit of the RS485 transceiver block 130 and has a function of transmitting signals to the master device 300 or other slave devices 100 . The input unit 134 is implemented by, for example, the switch 140 and the voltage source described above, and has a function of receiving a HIGH or LOW input signal and passing it to the control unit 111 . The input unit 134 may also have a function of receiving operation input from an input device (keypad, etc.) not shown. The output unit 135 is implemented by, for example, a display, a speaker, etc. (not shown), and has a function of outputting data to be presented to a user or the like.

The storage unit 121 is implemented by cooperation of the nonvolatile memory 120 and the MCU 110 described above. Storage unit 121 includes program storage unit 122 and parameter storage unit 123 .

Program storage unit 122 stores various programs executed to operate slave device 100 . For example, the program storage unit 122 stores a boot program that is executed when the slave device 100 is booted, a first program that operates the slave device 100 in the normal mode, a second program that operates the slave device 100 in the pseudo-master mode, memorize

The parameter storage unit 123 stores system reservation parameters. The system reservation parameters may include the ID of its own device, the maximum number of connected master devices 300 N, and the ID of the master device 300 . The ID of the own device is a default ID or an updated ID. In system 1000, the number of IDs corresponding to the maximum number N of connections is used. Therefore, the maximum number of connected devices N can be rephrased as information about IDs that can be used in the system (communication network) 1000 .

The control unit 111 is implemented by cooperation of the MCU 110 and the nonvolatile memory 120 described above. Control unit 111 includes determination unit 112 , slave function unit 113 , generation unit 114 , acquisition unit 115 , determination unit 116 , and update unit 117 .

The determination unit 112 is implemented by, for example, the MCU 110 executing a boot program when the slave device 100 is booted. The determination unit 112 receives an input signal from the input unit 134, and determines whether the slave device 100 is activated in the normal mode or in the pseudo master mode according to its LOW/HIGH (or ON/OFF of the switch 140). do.

The slave function unit 113 is implemented, for example, by the MCU 110 executing the first program when the determination unit 112 determines that the normal mode has been activated. The slave function unit 113 performs all functions of a normal slave device in the normal mode.

The generation unit 114, the acquisition unit 115, the determination unit 116, and the update unit 117 are implemented by the MCU 110 executing the second program when the determination unit 112 determines that the MCU 110 has been activated in the pseudo master mode, for example.

The generation unit 114 has a function of generating a response request to another device and outputting the generated response request to the transmission unit 133 . The response request includes a destination ID and a scan command. The transmission unit 133 transmits the response request received from the generation unit 114 to the adjacent slave device 100 via the serial communication path CP. In one embodiment, the generation unit 114 first reads the maximum number of connected master devices 300 N and the ID of the master device 300 (for example, “ID=1”) as system reservation parameters stored in the parameter storage unit 123 . Generation unit 114 generates a response request using all IDs available in system 1000, excluding the ID of master device 300, as destination IDs.

Acquisition unit 115 monitors the response to the transmitted response request and acquires information on the allocation status of usable IDs in system 1000 . Here, information about the allocation status means information as to whether each ID has been allocated to any other slave device 100 or has not been allocated to any slave device 100 (unassigned). In one embodiment, when a response is received from another slave device 100 via the reception unit 132, the acquisition unit 115 retrieves the response source ID included in the response (or the destination ID in the transmitted response request). is already assigned, and if no response is received, it is determined that the destination ID in the transmitted response request has not been assigned, thereby acquiring information on the above assignment status.

The determining unit 116 determines an ID to be assigned to the own device from unassigned IDs that have not been assigned to other slave devices 100 based on the information about the assignment status acquired by the acquiring unit 115 . As an example, the determining unit 116 determines the ID with the smallest number among the unassigned IDs as the ID to be assigned to the own device.

The updating unit 117 updates the ID of the own device stored in the parameter storage unit 123 with the ID determined by the determining unit 116 . The updating unit 117 further outputs a reboot request. When the update unit 117 outputs a reboot request, the control unit 111 terminates all programs being executed and reboots (restarts) the slave device 100 .

(3) Master Device The master device 300, like the slave device 100, may comprise a processor, memory, and transceiver block. The processor centrally controls the operation of master device 300 . The processor is typically a CPU (Central Processing Unit) or GPU (Graphics Processing Unit), but may be MCU, FPGA (Field Programmable Gate Array), DSP (Digital Signal Processor), or other general-purpose or dedicated processors. It can be. The memory includes volatile memory such as RAM and non-volatile memory such as ROM. The non-volatile memory of the master device 300, like the non-volatile memory 120 of the slave device 100, can store system reservation parameters (including the maximum number of connections N and the ID of its own device).

(motion)
A device according to one embodiment is a slave device 100 capable of executing an ID determination operation (an ID determination method) described later in the system 1000 . The ID determination operation is performed by activating the newly connected slave device 100 in pseudo-master mode while the master device 300 is disconnected from the system 1000 . Note that not all slave devices 100 in system 1000 need to be slave devices 100 capable of executing ID determination operations.

For example, first, a plurality of slave devices 100 are installed at predetermined positions within the system 1000 in a power-off state. After installation, two slave devices 100 out of the plurality of slave devices 100 are connected via the half-duplex serial communication path CP without connecting the master device 300 . Of the two connected slave devices 100, the slave device 100 whose ID is to be rewritten is activated while pressing the switch 140, thereby activating the slave device 100 in the pseudo master mode. Another slave device 100 is booted in normal mode (without pressing switch 140).

A slave device 100 activated in pseudo master mode (hereinafter also referred to as a “pseudo master device”) behaves like a master device. The pseudo master device sequentially scans the slave devices 100 hanging on the half-duplex serial bus using IDs that can be used in the system 1000, and grasps the allocation status of each ID. The pseudo-master device determines an ID to be assigned to itself from available IDs (unassigned IDs). The pseudo master device performs a process of rewriting information stored in the nonvolatile memory 120 from an ID reserved by the system in advance (for example, default setting) to a determined ID. The pseudo master device completes the ID rewriting process by rebooting after rewriting. That is, the rebooted slave device 100 reads the rewritten ID from the non-volatile memory 120 , normally boots up, and reconnects to the system 1000 . When adding a new slave device 100, by repeating the above procedure, the ID of the slave device 100 to be added can be automatically rewritten. Such an ID rewriting operation can be performed not only when the system 1000 is initially connected, but also when the slave device 100 is replaced due to maintenance, failure, or the like.

FIG. 4 is a flowchart illustrating an example of operations by the slave device 100 according to one embodiment.
ACT1 may be executed by the determination unit 112, for example. As ACT1, the determination unit 112 determines the operation mode set when the slave device 100 is started. When the input signal received from the input unit 134 is LOW (the switch 140 is ON), the determination unit 112 determines that the pseudo master mode is set, and the slave device 100 executes ACT2 to ACT11. On the other hand, when the input signal received from the input unit 134 is HIGH (the switch 140 is OFF), the determination unit 112 determines that the normal mode is set, and the slave device 100 executes ACT12.

ACT2 may be performed by the generator 114, for example. As ACT 2 , the generation unit 114 reads system reservation parameters (parameters) from the parameter storage unit 123 . As an example, the generation unit 114 reads the ID of its own device (for example, ID=2), the maximum number of connected master devices 300 N, and the ID of the master device 300 (for example, ID=1) as system reservation parameters. . In this example, the IDs available in system 100 are ID=2, 3, 4, . . . N, N+1.

ACT3 may be performed by the generator 114, for example. As ACT 3, the generation unit 114 sets a destination ID used for the response request based on the read parameters. As an example, the generator 114 sets “destination ID=2” using the smallest ID excluding the ID of the master device 300 (ID=1). By intentionally assigning IDs to the master devices 300 in this way, it is clear from the system specifications which IDs should be excluded from scanning for the maximum number N of connections by the slave devices 100 activated in the pseudo-master mode. can be As an arbitrary process in ACT3, the slave device 100 activated in the pseudo master mode can provisionally rewrite the ID of its own device to "ID=1".

ACT4 may be performed by the generator 114, for example. As ACT4, the generation unit 114 generates a response request ““destination ID”+“transmission command””, outputs it to the transmission unit 133, and causes it to be transmitted to the half-duplex serial communication path CP. An example of a send command is a "status check" command. For example, the slave device 100 that has received the response request ““2”+“status check” returns a predetermined response to the “status check” command when the self-device ID is “2”.

ACT5 may be performed by the acquisition unit 115, for example. In ACT5, the acquisition unit 115 monitors responses from other slave devices 100 to the transmitted response request. If a response has been received (YES), slave device 100 performs ACT6. If no response is received (NO), slave device 100 performs ACT7.

ACT6 may be performed by the acquisition unit 115, for example. As ACT6, when the response is received, the acquisition unit 115 stores the response source ID included in the response (or the destination ID in the transmitted response request) as an assigned ID in the storage unit 121 or the like.

ACT7 may be performed by the acquisition unit 115, for example. In ACT7, when the response is not received, the acquisition unit 115 stores the destination ID in the transmitted response request in the storage unit 121 or the like as an unassigned ID.

ACT8 may be performed by the generator 114, for example. In ACT8, the generating unit 114 determines whether scanning using all available IDs has been completed. For example, the generation unit 114 determines that scanning is completed when the destination ID used to generate the response request immediately before is equal to "N+1", and determines that scanning is not completed otherwise. If it is determined that scanning has ended (YES), the slave device 100 executes ACT10. If it is determined that scanning has not ended (NO), the slave device 100 executes ACT9.

ACT9 may be performed by the generator 114, for example. As ACT9, the generation unit 114 increments the setting value of the destination ID (ID=ID+1), and executes ACT4 to ACT8 again.

ACT 10 may be performed by decision unit 116, for example. As ACT 10, the determination unit 116 reads the allocation status information acquired by the acquisition unit 115, and determines the ID to be allocated to its own device. The allocation status information includes information as to whether each ID has been determined as assigned or unassigned. As an example, the determining unit 116 determines the smallest ID among the IDs determined to be unassigned as the ID of the own device.

ACT 11 may be executed by updater 117, for example. As ACT 11, the updating unit 117 rewrites (updates) the ID of the own device stored in the storage unit 121 with the determined ID, and outputs a reboot request. When the reboot request is output from the update unit 117 , the control unit 111 terminates all running programs and reboots the slave device 100 .

ACT 12 may be executed by slave function unit 113, for example. As ACT 12, slave function unit 113 performs normal slave device operations in normal mode. The operation in the normal mode may be arbitrarily set by an administrator of the system 1000 or the like. As an example, the slave function unit 113 passes a signal received from an adjacent device via the serial communication path CP to the adjacent device on the opposite side, and operates to take a predetermined action only when a command addressed to itself is received. do.

FIG. 5 is a diagram illustrating an example of commands transmitted and received by the slave device 100 according to one embodiment. The slave device 100 (pseudo master device) operating in the pseudo master mode generates a response request ““destination ID”+“transmission command””. Here, it is assumed that the destination ID is represented by two digits, and "status confirmation" is used as the transmission command. After transmission, the pseudo master device disables the transmission circuit, enables the reception circuit, and waits for a predetermined waiting time. If the slave device 100 corresponding to the destination ID exists within the system 1000, the slave device 100 generates and transmits a response ““response source ID”+“response command””. When the response is received, the pseudo master device determines that the response source ID included in the received response (destination ID included in the transmitted response request) is "ID assigned". If the slave device 100 corresponding to the destination ID does not exist in the system 1000, the response will not be received and will time out, and the pseudo master device will enable the transmission circuit again. In this case, the pseudo master device determines that the destination ID used for the response request is "unassigned", increments the value of the destination ID, and continues scanning.

In the first scan of FIG. 5, the pseudo-master device generated a response request ““02”+“status confirmation”” and sent it to the serial communication path CP, as described with respect to ACT4. In response to this response request, the pseudo master device received a response ““02”+“OK”” from any slave device 100 in system 1000 . As a result, the pseudo master device has determined that "ID=02" has already been assigned.

In the second scan of FIG. 5, the response "03"+"OK" was received in response to the response request "03"+"status check". Therefore, the pseudo master device determined that "ID=03" was also assigned. Subsequently, in the third scan, no response was received for the response request ““04”+“status confirmation”” and timed out. Therefore, the pseudo master device judged "ID=04" to be an unassigned ID. Similarly, the pseudo master device incremented the ID by 1 and repeated scanning. In the Nth scan, no response to the response request using "ID=N+1" was received, and the pseudo master device determined that "ID=N+1" was unassigned. This completes the scan using all available IDs (2, 3, 4..., N+1).

In the example of FIG. 5, the smallest unassigned ID is "ID=04". Therefore, the pseudo master device determines "ID=04" as the ID to be assigned to itself, rewrites the memory, reboots, and ends the ID rewriting operation. As a result of scanning, if there is no unassigned ID, the pseudo master device may issue an alert, for example by light or sound, via the output unit 135 to alert the user.

FIG. 6 shows a first example of an ID determination method process according to an embodiment.
In FIG. 6, two slave devices 100 are connected via a half-duplex serial communication path CP. Assume that the first slave device 101 (ID=2) is activated in the normal mode and the second slave device is activated as the pseudo master device 201 while the master device 300 is disconnected. At this time, as described with respect to ACT 3 of FIG. 4, the ID stored in the memory of the pseudo master device 201 is arbitrarily changed from the default ID (ID=2) to the ID for the master device (ID=1) provisionally. can be rewritten to Next, the pseudo master device 201 scans the inside of the half-duplex serial communication network as described above, determines an ID to be assigned to itself (eg, ID=3), rewrites the memory, and reboots.

FIG. 7 illustrates a second example of an ID determination method process according to an embodiment.
FIG. 7 shows, as a slave device 201, how the pseudo master device 201 of FIG. 6 is activated in normal mode after rebooting. The self-device ID stored in the nonvolatile memory 120 of the slave device 201 is rewritten to "ID=3".

FIG. 8 illustrates a third example of an ID determination method process according to an embodiment.
FIG. 8 shows how a new third slave device is connected to the slave device 201 of FIG. 7 and activated as a pseudo master device 202 . The pseudo master device 202 has been provisionally rewritten from the default ID (ID=2) to the master device ID (ID=1). After that, the pseudo master device 202 can scan the serial communication network, determine an ID (for example, ID=4) to be assigned to its own device, and automatically perform rewriting in the same manner as described with reference to FIG. can. In this way, automatic ID rewriting can be repeatedly executed for up to N slave devices. 6 to 8, the first slave device 101 may be a device that does not operate in pseudo master mode.

(Application example)
A device and ID determination method according to an embodiment is applicable to a wide variety of applications. As an example, the device according to one embodiment can be implemented as head peripheral equipment in an inkjet printer that forms an image on a recording medium by ejecting ink droplets from a circulating liquid ejection head. Similarly, an ID determination method according to an embodiment can be used to determine the ID of a head peripheral. Examples of such applications are briefly described below.

FIG. 9 is a side view for explaining the outline of the inkjet printer 1 using the circulating liquid ejection head described above. The inkjet printer 1 includes a plurality of liquid ejection devices 10 , a head support mechanism 11 , a head drive mechanism 12 , a medium support mechanism 13 and a printer control device 14 .

The head support mechanism 11 supports a plurality of liquid ejection devices 10 in parallel in the direction of the arrow A. As shown in FIG. The head drive mechanism 12 reciprocates in the direction of the arrow A the plurality of liquid ejecting devices 10 that are directed in the direction of the arrow A by the head support mechanism 11 in parallel. The medium support mechanism 13 movably supports the recording medium S in a direction orthogonal to the direction of the arrow A at a position facing the plurality of liquid ejection devices 10 reciprocally moved in the direction of the arrow A by the head driving mechanism 12 . do. The printer control device 14 controls operations of components of the inkjet printer 1 including the head drive mechanism 12 .

The liquid ejection device 10 integrally includes a liquid ejection head 20 and a liquid circulation device 30 . The liquid ejection device 10 ejects a liquid, such as ink I, from the liquid ejection head 20 while reciprocating in the direction of arrow A by the head drive mechanism 12 , onto the recording medium S supported by the medium support mechanism 13 . Form the desired image.

A plurality of liquid ejection devices 10 eject a plurality of colors, for example, cyan ink, magenta ink, yellow ink, black ink, and white ink. The plurality of liquid ejection devices 10 have the same configuration although they use different inks. The color or characteristics of the ink I to be used are not limited. For example, instead of white ink, transparent glossy ink, special ink that develops color when irradiated with infrared rays or ultraviolet rays, or the like may be ejected.

FIG. 10 is a schematic diagram for explaining the configuration of the liquid ejection head 20 and the liquid circulation device 30 of the liquid ejection device 10. As shown in FIG. The liquid ejection head 20 includes an ink supply port 21 and an ink ejection port 22 . The liquid ejection head 20 forms an ink channel inside the liquid ejection head 20 so that the ink supplied from the supply port 21 is discharged from the discharge port.

The liquid ejection head 20 has a plurality of pressure chambers arranged in the middle of the ink flow path. The liquid ejection head 20 supplies ink to each pressure chamber through an ink channel. The liquid ejection head 20 has a nozzle and an actuator for each pressure chamber. The nozzles communicate with corresponding pressure chambers. The actuator displaces the volume of the corresponding pressure chamber. In the liquid ejection head 20, the volume of the pressure chamber is displaced by the action of the actuator, so that the ink I in the pressure chamber is ejected from the nozzle communicating with the pressure chamber. The liquid ejection head 20 ejects from the ejection port 22 the ink in each pressure chamber that has not been ejected from the nozzles.

The liquid circulating device 30 is integrally connected to the liquid ejection head 20 by, for example, a metallic connecting part above the liquid ejection head 20 . The liquid circulation device 30 includes an upstream tank 31 , a downstream tank 32 , a replenishment tank 33 , a circulation pump 34 and a replenishment pump 35 . The upstream tank 31, downstream tank 32 and replenishment tank 33 are for storing the same type of ink. The circulation pump 34 is for feeding the ink stored in the downstream tank 32 to the upstream tank 31 . The replenishment pump 35 is for feeding the ink stored in the replenishment tank 33 to the upstream tank 31 .

The liquid circulation device 30 has a first pipeline 361 , a second pipeline 362 , a third pipeline 363 and a fourth pipeline 364 . The first pipeline 361 is a pipeline that connects the upstream tank 31 and the supply port 21 of the liquid ejection head 20 . The second pipeline 362 is a pipeline that connects the outlet 22 of the liquid ejection head 20 and the downstream tank 32 . The third pipeline 363 is a pipeline that connects the downstream tank 32 and the upstream tank 31 . A fourth pipeline 364 is a pipeline that connects the replenishment tank 33 and the upstream tank 31 .

Ink stored in the upstream tank 31 is sent to the supply port 21 of the liquid ejection head 20 through the first conduit 361 and passes through the ink flow path formed inside the liquid ejection head 20 . Ink discharged from the discharge port 22 of the liquid ejection head 20 through the ink channel is sent to the downstream tank 32 through the second conduit 362 and stored in the downstream tank 32 . The ink stored in the downstream tank 32 is sent to the upstream tank 31 through the third conduit 363 by the action of the circulation pump 34 and returns to the upstream tank 31 .

In this manner, the first pipeline 361, the second pipeline 362, and the third pipeline 363 are pipelines for circulating ink, which is liquid, between the upstream tank 31, which is a liquid chamber, and the liquid ejection head 20. A so-called circulation path 36 is constructed.

The liquid ejection apparatus 10 ejects ink circulating through the circulation path 36 from the liquid ejection head 20 . Therefore, the amount of ink stored in the upstream tank 31 is reduced. When the ink runs low, the ink stored in the replenishment tank 33 is sent to the upstream tank 31 through the fourth pipe line 364 by the action of the replenishment pump 35, and the upstream tank 31 is replenished.

The liquid circulation system 30 has liquid level sensors 41 and 42 inside the upstream tank 31 and the downstream tank 32, respectively. A liquid level sensor 41 detects the amount of ink in the upstream tank 31 . A liquid level sensor 42 detects the amount of ink in the downstream tank 32 . Based on the detection results of the liquid level sensors 41 and 42 , the printer control device 14 appropriately controls the replenishment pump 35 to replenish the ink in the replenishment tank 33 to the upstream tank 31 . The printer control device 14 replenishes the ink in the replenishment tank 33 to the upstream tank 31 to adjust the amount of ink circulating in the circulation path 36 to an appropriate amount.

The liquid circulation system 30 has pressure sensors 43 and 44 in the upstream tank 31 and the downstream tank 32, respectively. A pressure sensor 43 detects the pressure in the upstream tank 31 . A pressure sensor 44 detects the pressure in the downstream tank 32 . The liquid circulation device 30 has a pressure adjustment mechanism 45 . The pressure adjustment mechanism 45 opens the upstream tank 31 and the downstream tank 32 to the atmosphere, or pressurizes and depressurizes the downstream tank 32 . The printer control device 14 appropriately controls the pressure adjustment mechanism 45 based on the detection results of the pressure sensors 43 and 44 to adjust the pressure in the circulation path 36 . The printer control device 14 adjusts the ink pressure of the nozzles in the liquid ejection head 20 by adjusting the pressure of the circulation path 36 .

The liquid circulation device 30 has a heater 51 in the middle of the first pipe line 361 . The heater 51 is for heating the ink flowing through the first conduit 361 . The liquid circulation device 30 is provided with a first temperature sensor 52 on the heater 51 . The first temperature sensor 52 is for detecting the temperature of the heater 51 . Also, the liquid circulation device 30 is provided with the second temperature sensor 53 in the middle of the second pipe line 362 . The second temperature sensor 53 is for detecting the temperature of ink flowing through the second conduit 362 . Based on the detection result of the second temperature sensor 53, the printer control device 14 controls the power ON/OFF of the heater 51 to adjust the temperature of the ink flowing through the circulation path 36 to an appropriate value. Further, the printer control device 14 prevents overheating of the heater 51 based on the detection result of the first temperature sensor 52 .

FIG. 11 is a block diagram showing the main circuit configuration of the printer control device 14. As shown in FIG. The printer control device 14 includes a processor 61 , a ROM (Read Only Memory) 62 , a RAM (Random Access Memory) 63 , a timer 64 , an operation panel 65 , a communication interface 66 , a motor 67 and a liquid ejection device interface 68 . Printer controller 14 connects processor 61 , ROM 62 , RAM 63 , timer 64 , operation panel 65 , communication interface 66 , motor 67 and liquid ejector interface 68 via system bus 69 . System bus 69 includes an address bus, a data bus, and the like.

The processor 61 controls each part to realize various functions of the inkjet printer 1 according to the operating system and application programs.

ROM 62 stores the above operating system and application programs. The ROM 62 may store data necessary for the processor 61 to execute processing for controlling each unit.

The RAM 63 stores data necessary for the processor 61 to execute processing. The RAM 63 is also used as a work area in which information is appropriately rewritten by the processor 61 . The work area includes an image memory in which print data is developed.

A timer 64 keeps time.
The operation panel 65 has an operation section and a display section. The operation unit has function keys such as a power key and an error reset key. The display section can display various states of the inkjet printer 1 .

The communication interface 66 receives print data from a client terminal connected via a system such as a LAN (Local Area Network). For example, when an error occurs in the inkjet printer 1, the communication interface 66 transmits a signal notifying the error to the client terminal or the like.
A motor 67 is a drive source for the head support mechanism 11 and medium support mechanism 13 .

The liquid ejector interface 68 relays signals sent and received between the processor 61 and the plurality of liquid ejectors 10 . Signals sent from the processor 61 to the liquid ejection device 10 are signals for controlling the driving of the liquid ejection head 20 and for driving the circulation pump 34 , the supply pump 35 , the pressure adjustment mechanism 45 and the heater 51 in the liquid circulation device 30 . It is a signal etc. to control. Signals transmitted from the liquid ejection device 10 to the processor 61 are detection signals of the liquid level sensors 41, 42, pressure sensors 43, 44, first and second temperature sensors 52, 53 in the liquid circulation device 30, and the like.

In such a configuration, the processor 61 has at least a function as an ink heating control 611 and a function as an overheating monitoring control 612 . These functions are provided for each liquid ejection device 10 . These functions are implemented by programs stored in the ROM 62 .

In the inkjet printer 1 as described above, for example, the slave device 100 is implemented as the liquid circulation device 30 connected to the liquid ejection head 20, and the master device 300 is implemented as the printer control device . Printer controller 14 and liquid circulator 30 are daisy-chained by half-duplex serial communication. The liquid circulation device 30 can control the operations of the circulation pump 34, the replenishment pump 35, the heater 51, etc. according to commands from the printer control device 14. FIG.

At the time of initial installation, the ID of the liquid circulator 30 remains in the shipping state (default ID). When the master device and the slave device are one-to-one, half-duplex serial communication is possible even with the IDs in the shipment state. However, when adding more slave devices, it is necessary to assign a different ID to each slave device. ID rewriting is required. The inkjet printer 1 may use a plurality of liquid ejection heads 20 for ink of one color, and if five colors are used, the number of liquid ejection heads 20 is five times as large. Since the liquid circulation device 30 is installed for each liquid ejection head 20, it is very troublesome to assign an ID and rewrite it each time it is installed.

Therefore, as described above, the printer control device 14 as the master device 300 is once disconnected, the two liquid circulation devices 30 are connected, one is activated in the normal mode, and the other is activated in the pseudo master mode. The liquid circulator 30 activated in the pseudo master mode executes dedicated firmware (second program) stored in the nonvolatile memory. As a pseudo master device, the liquid circulating device 30 reads out the maximum number N of connected devices reserved for the system, scans using the IDs of the N devices (ID=2, 3, . . . N+1), and An ID to be assigned to the own device is determined from IDs not assigned to the liquid circulator 30, and the ID of the own device is automatically rewritten. After that, by connecting a new liquid circulation device 30 and activating it in the pseudo master mode, automatic ID rewriting can be repeatedly executed.

(effect)
As described in detail above, in one embodiment, in a serial communication network 1000 in which slave devices 100 (peripheral devices, etc.) are multidrop-connected to a master device 300 (controller, etc.), only the slave devices 100 are connected and sequentially , activates the slave device 100 to be added in the pseudo-master mode. The slave device 100 is activated in the pseudo-master mode by the user or the like pressing the switch 140 and activating it. The slave device 100 activated in pseudo-master mode executes dedicated firmware and performs the ID determination method. The ID determination method uses an ID that can be used in a serial communication network to generate and output a response request to another device, acquires information about the status of ID allocation based on the response to the response request, Based on this, an ID to be assigned to its own device is determined. Further, the slave device 100 activated in the pseudo master mode performs processing to rewrite the non-volatile memory of its own device with the determined ID.

As described above, according to one embodiment, a device connected to a serial communication network can automatically determine an ID to be assigned to the device itself. Therefore, a technology for facilitating ID assignment to a device connected to the serial communication network. can be provided.

[Other embodiments]
In addition, this invention is not limited to the said embodiment. For example, each functional unit included in the slave device 100 may be distributed to a plurality of devices, and these devices may cooperate with each other to perform processing. Also, each functional unit may be realized by using a circuit. A circuit may be a dedicated circuit that implements a specific function, or it may be a general-purpose circuit such as a processor.

Furthermore, the operations (ACT1-ACT12) described above are not limited to the illustrated order. Some operations may be reordered and some operations may be performed concurrently.

The slave device 100 activated in pseudo-master mode may first perform an operation to confirm that the master device 300 is not connected. For example, first, a response request using "ID=1" may be transmitted, and when a response is received in response to this, an alert with light or sound may be emitted to call the attention of the user.

The method described above can be executed by a computer (computer) as a program (software means), such as a magnetic disk (floppy (registered trademark) disk, hard disk, etc.), an optical disk (CD-ROM, DVD, MO, etc.) , semiconductor memory (ROM, RAM, flash memory, etc.) or other recording medium (storage medium), or can be transmitted and distributed via a communication medium. The programs stored on the medium also include a setting program for configuring software means (including not only execution programs but also tables and data structures) to be executed by the computer. A computer that implements the above apparatus reads a program recorded on a recording medium, and in some cases, constructs software means by a setting program, and executes the above-described processes by controlling the operation of the software means. The term "recording medium" as used herein is not limited to those for distribution, and includes storage media such as magnetic disks, semiconductor memories, etc. provided in computers or devices connected via a network.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

REFERENCE SIGNS LIST 1 inkjet printer 10 liquid ejection device 11 head support mechanism 12 head drive mechanism 13 medium support mechanism 14 printer control device 20 liquid ejection head 21 supply port 22 discharge port , 30... Liquid circulation device 31... Upstream tank 32... Downstream tank 33... Supply tank 34... Circulation pump 35... Supply pump 36... Circulation path 41, 42... Liquid level sensor 43, 44... Pressure Sensor 45 Pressure adjustment mechanism 51 Heater 52 First temperature sensor 53 Second temperature sensor 61 Processor 64 Timer 65 Operation panel 66 Communication interface 67 Motor 68 Device interface 69 System bus 100, 101, 102, 103, 104 Slave device 111 Control unit 112 Discrimination unit 113 Slave function unit 114 Generation unit 115 Acquisition unit 116 Decision Unit 117 Update unit 120 Non-volatile memory 121 Storage unit 122 Program storage unit 123 Parameter storage unit 130 Transceiver block 131 Interface unit 132 Receiving unit 133 Transmitting unit 134... Input part 135... Output part 140... Switch 150... Resistor 201, 202... Pseudo master device 300... Master device 361... First channel 362... Second channel 363... Third channel 364 Fourth channel 611 Ink heating control 612 Overheating monitoring control 1000 System.

Claims (5)

A device connectable to a serial communication network,
a generation unit that generates and outputs a response request to another device connected to the serial communication network using an ID that can be used in the serial communication network;
an acquisition unit that acquires information about the allocation status of the usable IDs in the serial communication network based on the response from the other device to the response request;
and a determining unit that determines an ID to be assigned to the own device based on the information about the assignment status. The serial communication network includes a slave device capable of transmitting a response to the response request when receiving a response request to which the ID of the device itself is attached as a destination,
The generation unit generates and outputs the response request to which each ID usable in the serial communication network is attached as a destination,
The acquisition unit acquires information about the allocation status based on whether or not the slave device has responded to the response request.
A device according to claim 1 . a first mode of operation, operating as the slave device within the serial communication network;
a second mode of operation operating as a master device capable of transmitting said response request to said slave device within said serial communication network;
3. The device of claim 2, comprising: 4. The device of claim 3, comprising a switch switchable between said first mode of operation and said second mode of operation. An identity determination method performed by a device connectable to a serial communication network, comprising:
generating and outputting a response request to another device connected to the serial communication network using an ID that can be used in the serial communication network;
Acquiring information about the allocation status of the usable IDs in the serial communication network based on the response from the other device to the response request;
and determining an ID to be assigned to the own device based on the information about the assignment status.

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