Encoder and measurement system

Abstract

The present invention comprises: a control unit 110; a memory 120; a sensing unit 150; a signal processing unit 160 for generating state detection information from the detection results of the sensing unit 150; and a communication unit 130. When a setting request signal including a new one-rotation reset execution propriety setting value is received from a controller 10, the new one-rotation reset execution propriety setting value is stored in the memory 120. Upon receiving a one-rotation reset request signal from the controller 10, the control unit 110 does not execute a one-rotation reset if the stored one-rotation reset execution propriety setting value is a reset execution non-permission setting, and does execute the one-rotation reset if the stored one-rotation reset execution propriety setting value is a reset execution permission setting.

Description

Encoders and Measuring Systems

[0001] The present invention relates to encoders and measurement systems, and more particularly to an improvement in one-turn reset in encoders.

[0002] The user attaches the encoder to a measurement target device such as a motor, mechanically aligns the motor's magnetic pole position with the encoder's reference position, and then performs an electrical alignment called a "one-rotation reset" to synchronize the motor's magnetic pole position with the encoder's reference position. In this case, when the encoder receives a one-rotation reset request signal from an external controller, it resets the one-rotation position at the time of reception as the origin position of 0.

[0003] The technology relating to this one-rotation reset is disclosed in the following Patent Document 1.

[0004] Japanese Patent Application Publication No. 08-189826

[0005] Although the above-mentioned Patent Document 1 does not disclose details, a setting value for whether or not to permit execution of one-rotation reset is stored in a non-volatile memory within the encoder.

[0006] If a user accidentally performs a one-rotation reset, the alignment between the motor's magnetic poles and the encoder may become distorted, resulting in problems such as an inability to perform normal position detection. To prevent this from happening, it is desirable to change the settings in the non-volatile memory so that a one-rotation reset cannot be performed again after the user has successfully performed a one-rotation reset.

[0007] However, the setting in the nonvolatile memory as to whether or not to execute the one-rotation reset is performed by connecting a setting device to a dedicated port before shipping the encoder. This has prevented users from arbitrarily changing the setting as to whether or not to execute the one-rotation reset. Therefore, it is desired that users be able to change the setting in the nonvolatile memory as to whether or not to execute the one-rotation reset without using a setting device.

[0008] An object of the present invention is to provide an encoder and a measurement system that allows settings in a non-volatile memory regarding whether or not to allow one-rotation reset to be performed to be changed from an external controller without using a setting device.

[0009] The encoder according to the present invention comprises a control unit, a non-volatile memory, a sensing unit that detects the state of the equipment to be measured, a signal processing unit that generates state detection information from the detection results of the sensing unit, and a communication unit that communicates with an external controller, wherein the memory stores a one-rotation reset execution permission / prohibition setting value whose content is a reset execution permission setting or a reset execution prohibition setting, and when the control unit receives a transmission request signal from the controller via the communication unit, it controls the state detection information generated by the signal processing unit to be sent to the controller via the communication unit, and when it receives a setting request signal from the controller via the communication unit that includes a new one-rotation reset execution permission / prohibition setting value, it stores the new one-rotation reset execution permission / prohibition setting value in the memory, and when it receives a one-rotation reset request signal from the controller via the communication unit, it controls the one-rotation reset not to be performed if the one-rotation reset execution permission / prohibition setting value stored in the memory is a reset execution prohibition setting, and controls the one-rotation reset to be performed if the one-rotation reset execution permission / prohibition setting value stored in the memory is a reset execution permission setting.

[0010] In the encoder of the present invention, the one-rotation reset execution permission setting value includes a reset execution permission setting or a reset execution non-permission setting, and the reset execution non-permission setting may further include a changeable reset execution non-permission setting or an unchangeable reset execution non-permission setting.

[0011] In the encoder of the present invention, when the one-rotation reset execution permission setting value included in the one-rotation reset request signal is a changeable reset execution not permitted setting, if the one-rotation reset execution permission setting value stored in the memory is a non-changeable reset execution not permitted setting, the control unit may not rewrite the one-rotation reset execution permission setting value stored in the memory, but if the one-rotation reset execution permission setting value stored in the memory is a reset execution permission setting, the control unit may rewrite the one-rotation reset execution permission setting value stored in the memory to a changeable reset execution not permitted setting.

[0012] In the encoder of the present invention, when the one-rotation reset execution permission setting value included in the one-rotation reset request signal is a reset execution permission setting, if the one-rotation reset execution permission setting value stored in the memory is an unchangeable reset execution permission setting, the control unit may not rewrite the one-rotation reset execution permission setting value stored in the memory, but if the one-rotation reset execution permission setting value stored in the memory is an changeable reset execution permission setting, the control unit may rewrite the one-rotation reset execution permission setting value stored in the memory to a reset execution permission setting.

[0013] In the encoder of the present invention, if the one-rotation reset execution permission setting value included in the one-rotation reset request signal is an unchangeable reset execution permission setting, and if the one-rotation reset execution permission setting value stored in the memory is a reset execution permission setting or a changeable reset execution permission setting, the control unit may rewrite the one-rotation reset execution permission setting value stored in the memory to an unchangeable reset execution permission setting.

[0014] In the encoder according to the present invention, the control unit has a function of responding to memory access from the controller and writing data to a specified address in the memory, and when it receives a one-rotation reset request signal in the form of a memory access command from the controller via the communication unit, the request signal includes a new one-rotation reset execution enable / disable setting value and an address in memory of the new one-rotation reset execution enable / disable setting value, the control unit may write the new one-rotation reset execution enable / disable setting value to the address in the memory.

[0015] In the encoder according to the present invention, the control unit may read the one-rotation reset execution possibility setting value stored in the memory when the power is turned on, and determine whether or not to execute the one-rotation reset based on the read one-rotation reset execution possibility setting value.

[0016] The measurement system according to the present invention comprises a controller that communicates with an encoder, and any of the encoders described above that communicates with the controller; when the controller sends a request signal for transmission to the encoder, the encoder sends status detection information to the controller in response to the request signal for transmission; when the controller sends a request signal for setting to the encoder including a one-rotation reset execution permission / prohibition setting value whose content is a reset execution permission setting or a reset execution prohibition setting, the encoder stores the one-rotation reset execution permission / prohibition setting value in memory in response to the request signal for setting; when the controller sends a request signal for one-rotation reset to the encoder, the encoder does not perform a one-rotation reset if the one-rotation reset execution permission / prohibition setting value stored in memory is a reset execution prohibition setting, and performs a one-rotation reset if the one-rotation reset execution permission / prohibition setting value stored in memory is a reset execution permission setting.

[0017] According to the encoder of the present invention, it is possible to change the setting in the nonvolatile memory regarding whether or not to permit execution of a one-rotation reset from an external controller. According to the measurement system of the present invention, it is possible to change the setting in the nonvolatile memory regarding whether or not to permit execution of a one-rotation reset of the encoder from a controller.

[0018] FIG. 1 is a configuration diagram showing the configuration of a measurement system including a controller and an encoder in embodiment 1. FIG. 2 is a configuration diagram showing the encoder in embodiment 1 together with the signal flow. FIG. 3 is an explanatory diagram showing a rewrite state of a one-rotation reset execution permission setting value in embodiment 1. FIG. 4 is an explanatory diagram showing an example of the format of a memory access command used in embodiment 1. FIG. 5 is a configuration diagram showing the configuration of a measurement system including a controller and an encoder in a comparative example. FIG. 6 is a configuration diagram showing the encoder in the comparative example together with the signal flow.

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An encoder and a measurement system according to an embodiment of the present invention will now be described with reference to the accompanying drawings. In the drawings, the same parts are designated by the same reference numerals.

[0020] First Embodiment First, the configuration of a measurement system 1 in a first embodiment will be described with reference to Fig. 1. Fig. 1 is a configuration diagram showing the configuration of a measurement system 1 including a controller 10 and an encoder 100 in the first embodiment. Here, the controller 10 functions as a host computer, and the encoder 100 functions as a terminal device.

[0021] 1, the encoder 100 is configured to be able to communicate with an external controller 10. The encoder 100 mainly includes a control unit 110, a memory 120, a communication unit 130, a sensing unit 150, and a signal processing unit 160.

[0022] The control unit 110 includes a request determination unit 111 , a signal processing controller 112 , a memory controller 113 , a one-rotation reset determination unit 114 , and a one-rotation reset execution unit 115 .

[0023] The request determination unit 111 determines and distributes each of the transmission request signal, setting request signal, and one-rotation reset request signal from the controller 10. That is, the request determination unit 111 provides the transmission request signal to the signal processing controller 112 (see b in FIG. 1 ), the setting request signal to the memory controller 113 (see d in FIG. 1 ), and the one-rotation reset request signal to the one-rotation reset determination unit 114 (see e in FIG. 1 ). Here, the transmission request signal is a general request signal known as RTS (Request To Send), which requests the controller 10 to transmit status detection information generated by the signal processing unit 160 based on the detection result of the sensing unit 150. The one-rotation reset request signal is a signal from the controller 10 to the encoder 100 to execute a one-rotation reset. The setting request signal is a signal that includes a new one-rotation reset execution permission setting value and requests the encoder 100 to update the one-rotation reset execution permission setting value. The one-rotation reset request signal and the setting request signal are signals that are realized by partially modifying or expanding the bits that make up a general transmission request signal.

[0024] When the signal processing controller 112 receives a request signal for a transmission request from the external controller 10 via the request determination unit 111, it controls the signal processing unit 160 to transmit the status detection information (see k in Figure 1) generated by the signal processing unit 160 to the controller 10 via the communication unit 130.

[0025] When the encoder 100 is powered on, the memory controller 113 reads the one-rotation reset execution permission / prohibition setting value stored in the memory 120 (see f in FIG. 1 ) and supplies the read one-rotation reset execution permission / prohibition setting value to the one-rotation reset determination unit 114 (see g in FIG. 1 ). When the memory controller 113 receives a setting request signal including a new one-rotation reset execution permission / prohibition setting value from the controller 10 via the request determination unit 111 (see d in FIG. 1 ), if the contents stored in the memory 120 can be changed, the memory controller 113 stores the new one-rotation reset execution permission / prohibition setting value in the memory 120 (see f in FIG. 1 ). On the other hand, when the memory controller 113 receives a setting request signal including a new one-rotation reset execution permission / prohibition setting value from the controller 10 and the contents stored in the memory 120 cannot be changed, the memory controller 113 does not store the new one-rotation reset execution permission / prohibition setting value in the memory 120.

[0026] When the one-rotation reset determination unit 114 receives a one-rotation reset request signal from the controller 10 via the request determination unit 111 (see e in FIG. 1), if the one-rotation reset execution permission setting value (see g in FIG. 1) from the memory controller 113 is set to permit reset execution, the one-rotation reset determination unit 114 commands the one-rotation reset execution unit 115 to execute a one-rotation reset (see h in FIG. 1). On the other hand, when the one-rotation reset request signal from the controller 10 via the request determination unit 111 (see e in FIG. 1), if the one-rotation reset execution permission setting value (see g in FIG. 1) from the memory controller 113 is set to prohibit reset execution, the one-rotation reset determination unit 114 does not command the one-rotation reset execution unit 115 to execute a one-rotation reset.

[0027] The one-rotation reset execution unit 115 receives a one-rotation reset execution command (see h in FIG. 1) from the one-rotation reset determination unit 114, and instructs the signal processing unit 160 to execute a one-rotation reset (see i in FIG. 1).

[0028] The memory 120 stores a one-rotation reset execution permission / prohibition setting value having a reset execution permission setting or a reset execution prohibition setting in response to control from the memory controller 113 (see f in FIG. 1). The memory 120 stores a one-rotation reset execution permission / prohibition setting value having a changeable reset execution prohibition setting or an unchangeable reset execution prohibition setting as the reset execution prohibition setting in response to control from the memory controller 113. Furthermore, the memory 120 may rewrite a one-rotation reset execution permission / prohibition setting value other than the one-rotation reset execution permission / prohibition setting value having an unchangeable reset execution prohibition setting in response to control from the memory controller 113.

[0029] The communication unit 130 includes a receiving unit 131 and a transmitting unit 132 for communicating with the external controller 10. The receiving unit 131 receives a transmission request signal, a setting request signal, and a one-rotation reset request signal from the controller 10 (see rx in FIG. 1). The transmitting unit 132 transmits the state detection information (see k in FIG. 1) generated by the signal processing unit 160 to the controller 10 (see tx in FIG. 1).

[0030] The sensing unit 150 magnetically or optically detects the state of the measurement target device, for example, the rotation angle of a rotating body such as a motor or a wheel, and supplies the detection result regarding the state of the measurement target device to the signal processing unit 160 (see j in FIG. 1 ).

[0031] The signal processing unit 160 processes the detection results of the sensing unit 150 and generates state detection information including the position, angle, or speed. The state detection information generated by the signal processing unit 160 is sent to the communication unit 130 under the control of the signal processing controller 112 in response to a transmission request signal from the controller 10 (see k in FIG. 1). The signal processing unit 160 receives an instruction to execute a one-rotation reset from the one-rotation reset execution unit 115 (see i in FIG. 1), and synchronizes the position of the device to be measured with the reference position of the encoder 100 as a position initialization process.

[0032] Comparative Example: Here, the configuration of a measurement system 1x as a comparative example to the measurement system 1 in the first embodiment will be described with reference to FIG. 5. FIG. 5 is a configuration diagram showing the configuration of a measurement system 1x including a controller 10x and an encoder 100x in the comparative example. In FIG. 5, in the configuration of the measurement system 1x, the same components as those in FIG. 1 are given the same reference numerals, and components different from those in FIG. 1 are given an "x" at the end of the reference numeral. Therefore, redundant explanations will be omitted, and the explanation will focus on the parts that are different from FIG. 1.

[0033] 5, the encoder 100x is configured to be able to communicate with an external controller 10x. The encoder 100x mainly includes a control unit 110x, a memory 120x, a communication unit 130, a sensing unit 150, and a signal processing unit 160.

[0034] The control unit 110x includes a request determination unit 111, a signal processing controller 112, a memory controller 113, and a one-rotation reset execution unit 115. The control unit 110x does not include the one-rotation reset determination unit 114 in the control unit 110 of the first embodiment.

[0035] Before shipping the encoder 100x, the memory 120x stores a one-rotation reset execution permission / prohibition setting value, which contains a reset execution permission setting or a reset execution prohibition setting, via a dedicated port or the like, as indicated by the dashed line [0] in Fig. 5. Generally, the memory 120x stores a one-rotation reset execution permission / prohibition setting value, which contains a reset execution permission setting, to enable a user to execute a one-rotation reset. The memory 120x supplies the stored one-rotation reset execution permission / prohibition setting value to the memory controller 113 in response to read control from the memory controller 113 (see f in Fig. 5).

[0036] [Operation of Encoder 100x in Comparative Example] The operation of the encoder 100x in the comparative example will be described with reference to Fig. 6. Fig. 6 is a configuration diagram showing the encoder 100x in the comparative example together with the signal flow. Below, the operation of the encoder 100x will be described separately for when it is manufactured, when it is installed, when it is powered on, when it receives a one-rotation reset request signal, and when it receives a transmission request signal.

[0037] During manufacturing (storing one-rotation reset execution permission setting value): Before shipping the encoder 100x, the manufacturer of the encoder 100x stores a one-rotation reset execution permission setting value, which contains a reset execution permission setting or a reset execution non-permission setting, in the memory 120x via a dedicated port or the like. When a one-rotation reset is executed by a user, the one-rotation reset execution permission setting value, which contains the reset execution permission setting, is stored in the memory 120x. The above-described flow of storing the one-rotation reset execution permission setting value is shown by the dashed line [0] in FIG. 6.

[0038] When the encoder 100x is installed: The shipped encoder 100x is attached to a measurement target device such as a motor, and is set in a state in which it can communicate with an external controller 10x.

[0039] When power is turned on: When power is turned on to the encoder 100, the control unit 110x initializes each component and controls each component to perform various initial operations. As an example of the initial operation, the memory controller 113 reads out the one-rotation reset execution permission setting value stored in the memory 120x (see f in FIG. 6). The memory controller 113 supplies the read one-rotation reset execution permission setting value to the request determination unit 111 (see d in FIG. 6). The flow of the one-rotation reset execution permission setting value described above is indicated by the dashed line [1] in FIG. 6. Note that the following description will be continued assuming that the one-rotation reset execution permission setting value includes a reset execution permission setting as its content.

[0040] When a one-rotation reset request signal is received: When the encoder 100x receives a one-rotation reset request signal from the controller 10x while the magnetic pole position of the motor and the reference position of the encoder 100x are aligned, the encoder 100x executes a one-rotation reset to synchronize the magnetic pole position of the motor and the reference position of the encoder 100x at the time of reception. The execution of the one-rotation reset will be described in detail below. The request determination unit 111 receives the one-rotation reset request signal from the controller 10x via the receiving unit 131 (see a in FIG. 6 ). If the one-rotation reset execution permission setting value indicates that the reset is permitted, the request determination unit 111 issues a one-rotation reset execution command to the one-rotation reset execution unit 115 to execute a one-rotation reset in response to the one-rotation reset request signal from the controller 10x (see e in FIG. 6 ). The one-rotation reset execution unit 115 receives the one-rotation reset execution command from the request determination unit 111 (see e in FIG. 6 ) and instructs the signal processing unit 160 to execute a one-rotation reset (see i in FIG. 6 ). The signal processing unit 160 receives an instruction to execute a one-rotation reset from the one-rotation reset execution unit 115 (see i in FIG. 6), and synchronizes the position of the measurement target device at that time with the reference position of the encoder 100x as a position initialization process. The flow of one-rotation reset execution in response to the one-rotation reset request signal and reset execution permission setting described above is shown by dashed lines [1] and [2] in FIG.

[0041] Upon receiving a transmission request signal: The transmission request signal from the controller 10x is received by the receiving unit 131 and supplied to the request determination unit 111 (see a in FIG. 6). The request determination unit 111 provides the transmission request signal to the signal processing controller 112 (see b in FIG. 6). Upon receiving the transmission request signal from the controller 10 via the request determination unit 111, the signal processing controller 112 controls the signal processing unit 160 to transmit the status detection information (see k in FIG. 6) generated by the signal processing unit 160 to the controller 10 via the communication unit 130. The flow of the status detection information in response to the transmission request signal is indicated by the dashed line [3] in FIG. 6.

[0042] Accidental execution of one-rotation reset: If a user mistakenly performs a one-rotation reset operation, the encoder 100x, which receives a one-rotation reset request signal from the controller 10x, executes a one-rotation reset. If the one-rotation reset is executed when the motor's magnetic pole position does not match the reference position of the encoder 100x, the alignment between the motor's magnetic pole and the encoder 100x will be misaligned. This will cause a problem in which normal position detection will no longer be possible. The setting in the memory 120x as to whether or not to execute a one-rotation reset is performed by connecting a setting device to a dedicated port before the encoder 100x is shipped. Therefore, if the memory 120x is set to allow execution of a one-rotation reset, it is not possible to prevent an erroneous execution of a one-rotation reset.

[0043] [Operation of Encoder 100 of First Embodiment] The operation of the encoder 100 of the first embodiment will be described with reference to Fig. 2. Fig. 2 is a configuration diagram showing the encoder 100 of the first embodiment together with the signal flow. Below, the operation of the encoder 100 will be described separately for when the power is turned on, when a one-rotation reset request signal is received, when a setting request signal is received, and when a transmission request signal is received.

[0044] When power is turned on: When the encoder 100 is turned on, the control unit 110 initializes each component and performs the following initial operations. As an example of the initial operation, the memory controller 113 reads the one-rotation reset execution permission / prohibition setting value stored in the memory 120 (see f in FIG. 2). The memory controller 113 supplies the read one-rotation reset execution permission / prohibition setting value to the one-rotation reset determination unit 114 (see g in FIG. 2). The one-rotation reset execution permission / prohibition setting value stored in the memory 120 may be either one stored by the manufacturer of the encoder 100 before shipping, or one stored as a new one-rotation reset execution permission / prohibition setting value updated by a setting request signal from the external controller 10. The one-rotation reset execution permission / prohibition setting value stored in the memory 120 is either a "reset execution permission setting" or a "reset execution prohibition setting." Furthermore, the "reset execution prohibition setting" may be either a "changeable reset execution prohibition setting" or an "unchangeable reset execution prohibition setting." Here, the explanation will be continued assuming that the one-rotation reset execution permission / prohibition setting value stored in the memory 120 includes the reset execution permission setting as an initial value.

[0045] Upon receiving a one-rotation reset request signal (1): The user transmits a one-rotation reset request signal from the controller 10 to the encoder 100 while aligning the reference position of the encoder 100 with the magnetic pole position of the motor. When the encoder 100 receives the one-rotation reset request signal from the controller 10, it executes a one-rotation reset so as to synchronize the magnetic pole position of the motor with the reference position of the encoder 100 at the time of reception. The execution of the one-rotation reset will be described in detail below. The one-rotation reset determination unit 114 receives the one-rotation reset request signal from the controller 10 via the receiving unit 131 and the request determination unit 111 (see a and e in FIG. 2). If the content of the one-rotation reset execution permission setting value ( g in FIG. 2 ) indicates that the reset execution is permitted, the one-rotation reset determination unit 114 commands the one-rotation reset execution unit 115 to execute a one-rotation reset in response to the one-rotation reset request signal from the controller 10 ( h in FIG. 2 ). The one-rotation reset execution unit 115 receives a command to execute a one-rotation reset from the one-rotation reset determination unit 114 (see h in FIG. 2), and instructs the signal processing unit 160 to execute a one-rotation reset (see i in FIG. 2). The signal processing unit 160 receives the command to execute a one-rotation reset from the one-rotation reset execution unit 115 (see i in FIG. 2), and synchronizes the position of the measurement target device at that time with the reference position of the encoder 100 as a position initialization process. The flow of one-rotation reset execution according to the one-rotation reset request signal and the reset execution permission setting described above is shown by dashed lines [1a] and [2] in FIG. 2.

[0046] When a setting request signal is received: The controller 10 transmits a setting request signal to the encoder 100, requesting that the one-rotation reset execution permission setting value be updated as necessary. The encoder 100 receives the setting request signal including the new one-rotation reset execution permission setting value from the controller 10 via the receiver 131 (see FIG. 2A). The one-rotation reset execution permission setting value from the controller 10 received by the receiver 131 is supplied from the request determination unit 111 to the memory controller 113 (see FIG. 2D). When the memory controller 113 receives the setting request signal including the new one-rotation reset execution permission setting value (see FIG. 2D), if the contents stored in the memory 120 can be changed, the memory controller 113 stores the new one-rotation reset execution permission setting value in the memory 120 (see FIG. 2F). The signal flow for storing the new one-rotation reset execution permission setting value in the memory 120 is shown by the dashed line [3a] in FIG. 2. On the other hand, if the memory controller 113 receives a setting request signal including a new one-rotation reset execution permission / prohibition setting value from the controller 10 but is unable to change the contents stored in the memory 120, it does not store the new one-rotation reset execution permission / prohibition setting value in the memory 120. The signal flow when the new one-rotation reset execution permission / prohibition setting value is not stored in the memory 120 is shown by the dashed line [3b] in Figure 2.

[0047] The manner in which the memory controller 113 stores or does not store a new one-rotation reset execution permission / prohibition setting value in the memory 120 will be described below with reference to FIG. 3. FIG. 3 is an explanatory diagram showing a rewrite state of the one-rotation reset execution permission / prohibition setting value in embodiment 1. The one-rotation reset execution permission / prohibition setting value already stored in the memory 120 will be referred to as the "stored one-rotation reset execution permission / prohibition setting value," and the new one-rotation reset execution permission / prohibition setting value sent from the controller 10 will be referred to as the "new one-rotation reset execution permission / prohibition setting value." Furthermore, "storing the new one-rotation reset execution permission / prohibition setting value in the memory 120" will be referred to as "rewriting the stored one-rotation reset execution permission / prohibition setting value with the new one-rotation reset execution permission / prohibition setting value," and "not storing the new one-rotation reset execution permission / prohibition setting value in the memory 120" will be referred to as "not rewriting the stored one-rotation reset execution permission / prohibition setting value."

[0048] In FIG. 3 , the new one-rotation reset execution permission setting values ​​are shown in the horizontal direction of the table as (a) a changeable reset execution permission setting, (b) a reset execution permission setting, and (c) an unchangeable reset execution permission setting. In FIG. 3 , the memorized one-rotation reset execution permission setting values ​​are shown in the vertical direction of the table as (d) a changeable reset execution permission setting, (e) a reset execution permission setting, and (f) an unchangeable reset execution permission setting. The results of overwriting or not overwriting the memorized one-rotation reset execution permission setting value are shown in a table format in (g) to (m) based on the combination of the new one-rotation reset execution permission setting values ​​(a) to (c) and the memorized one-rotation reset execution permission setting values ​​(d) to (f). Note that if the new one-rotation reset execution permission setting value and the unchangeable reset execution permission setting are the same, there is no need to overwrite the memorized one-rotation reset execution permission setting value, and this is indicated by a "-" in FIG. 3 .

[0049] If the new one-rotation reset execution permission setting value is the changeable reset execution permission setting ((a) in FIG. 3) and the stored one-rotation reset execution permission setting value is the unchangeable reset execution permission setting ((d) in FIG. 3), the memory controller 113 does not rewrite the stored one-rotation reset execution permission setting value ((g) in FIG. 3). If the new one-rotation reset execution permission setting value is the changeable reset execution permission setting ((a) in FIG. 3) and the stored one-rotation reset execution permission setting value is the reset execution permission setting ((e) in FIG. 3), the memory controller 113 rewrites the stored one-rotation reset execution permission setting value to the changeable reset execution permission setting ((h) in FIG. 3).

[0050] The memory controller 113 does not rewrite the stored one-rotation reset execution permission setting value ((i) in FIG. 3) when the new one-rotation reset execution permission setting value is the reset execution permission setting ((b) in FIG. 3) and the stored one-rotation reset execution permission setting value is the unchangeable reset execution prohibition setting ((d) in FIG. 3). The memory controller 113 rewrites the stored one-rotation reset execution permission setting value to the reset execution permission setting ((j) in FIG. 3) when the new one-rotation reset execution permission setting value is the reset execution permission setting ((b) in FIG. 3) and the stored one-rotation reset execution permission setting value is the changeable reset execution prohibition setting ((f) in FIG. 3).

[0051] If the new one-rotation reset execution permission setting value is the unchangeable reset execution permission setting ((c) in FIG. 3) and the stored one-rotation reset execution permission setting value is the reset execution permission setting ((e) in FIG. 3), the memory controller 113 rewrites the stored one-rotation reset execution permission setting value to the unchangeable reset execution permission setting ((k) in FIG. 3). If the new one-rotation reset execution permission setting value is the unchangeable reset execution permission setting ((c) in FIG. 3) and the stored one-rotation reset execution permission setting value is the changeable reset execution permission setting ((f) in FIG. 3), the memory controller 113 rewrites the stored one-rotation reset execution permission setting value to the unchangeable reset execution permission setting ((m) in FIG. 3).

[0052] In the first embodiment, in order to prevent a single rotation reset from being erroneously executed again after a single rotation reset has been successfully executed, it is preferable that the memory controller 113 rewrites the stored single rotation reset execution permission setting value, which contains the reset execution permission setting ((e) in FIG. 3 ), to a changeable reset execution prohibition setting ((h) in FIG. 3 ) or to an unchangeable reset execution prohibition setting ((k) in FIG. 3 ) based on an instruction from the controller 10. Alternatively, in order to execute a single rotation reset, it is preferable that the memory controller 113 rewrites the stored single rotation reset execution permission setting value, which contains the reset execution prohibition setting ((f) in FIG. 3 ), to a reset execution permission setting ((j) in FIG. 3 ). Furthermore, by changing the stored single rotation reset execution permission setting value ((e) or (f) in FIG. 3 ) to an unchangeable reset execution prohibition setting ((k) or (m) in FIG. 3 ), the stored single rotation reset execution permission setting value cannot be rewritten in the future, thereby permanently preventing erroneous single rotation resets. The memory controller 113 reads the one-rotation reset execution permission / prohibition setting value rewritten in the memory 120, and supplies the read one-rotation reset execution permission / prohibition setting value to the one-rotation reset determination unit 114 (see f and g in FIG. 2).

[0053] Upon receiving a transmission request signal: The controller 10 transmits a transmission request signal to the encoder 100 at regular time intervals, requesting status detection information indicating the status of the measurement target device. The transmission request signal from the controller 10 is received by the receiver 131 and supplied to the request determination unit 111 (see a in FIG. 2). The request determination unit 111 provides the transmission request signal to the signal processing controller 112 (see b in FIG. 2). Upon receiving the transmission request signal from the controller 10 via the request determination unit 111, the signal processing controller 112 controls the transmission of status detection information generated by the signal processing unit 160 (see k in FIG. 6) to the controller 10 via the communication unit 130. The flow of transmitting status detection information from the encoder 100 to the controller 10 in response to the transmission request signal from the controller 10 is shown by the dashed line [4] in FIG. 2.

[0054] When a one-rotation reset request signal is received (2): Due to a user error, the controller 10 may send a one-rotation reset request signal to the encoder 100. Because the user unintentionally commands a one-rotation reset, the motor's magnetic pole position and the reference position of the encoder 100 no longer match. The stored one-rotation reset execution permission setting in the memory 120 is rewritten to a changeable reset execution prohibition setting or an unchangeable reset execution prohibition setting to prevent a one-rotation reset from being accidentally executed again after it has been successfully executed. In the encoder 100, the one-rotation reset request signal from the controller 10 is received by the receiver 131 and supplied from the receiver 131 to the request determination unit 111 (see a in FIG. 2 ). The request determination unit 111 supplies the one-rotation reset request signal from the controller 10 to the one-rotation reset determination unit 114 (see e in FIG. 2 ). If the stored one-rotation reset execution permission setting value indicates that the reset execution is not permitted, the one-rotation reset determination unit 114 does not command the one-rotation reset execution unit 115 to execute a one-rotation reset, regardless of the one-rotation reset request signal from the controller 10. In this manner, it is possible to prevent the one-rotation reset from being erroneously executed when the magnetic pole position of the motor does not match the reference position of the encoder 100. The flow of information when the one-rotation reset is not executed due to the one-rotation reset request signal and the reset execution not permitted setting is shown by dashed lines [1b] and [5] in Figure 2.

[0055] Use of Memory Access: The setting request signal includes a new one-rotation reset execution permission / prohibition setting value. The new one-rotation reset execution permission / prohibition setting value includes one of a reset execution permission setting, a changeable reset execution permission / prohibition setting, and an unchangeable reset execution permission / prohibition setting. For this reason, it may be difficult to generate a setting request signal by partially modifying or expanding the bits constituting a general transmission request request signal. Therefore, in response to a one-rotation reset memory access command from the controller 10, the encoder 100 stores the new one-rotation reset execution permission / prohibition setting value at an address in the memory 120 specified by the one-rotation reset memory access command. The one-rotation reset memory access command includes the new one-rotation reset execution permission / prohibition setting value and the address in the memory 120 of the new one-rotation reset execution permission / prohibition setting value, and is a command to store the new one-rotation reset execution permission / prohibition setting value in the memory 120. For this reason, the memory controller 113 has a function of writing a new one-rotation reset execution permission / prohibition setting value to a specified address in the memory 120 in response to a one-rotation reset memory access command from the controller 10 .

[0056] The above-described one-rotation reset memory access command can be implemented using the communication format of a general direct memory access command shown in FIG. 4. FIG. 4 is an explanatory diagram showing an example of the format of a memory access command used in the first embodiment. For example, the fields in the format shown in FIG. 4 are as follows: The control field CF contains command information related to the type of command; The address field ADF contains information about the address used when writing to the memory 120; The data field EDF contains information about a new one-rotation reset execution enable / disable setting value to be written to the memory 120, the content of which includes a reset execution enable setting, a changeable reset execution disable setting, or an unchangeable reset execution disable setting; The check field CRC contains error check information using a CRC (Cyclic Redundancy Check) for all bits except the start bit and delimiter of all fields other than the CRC field. As a result, by using a request signal in the memory access command format, more information can be transmitted from the controller 10 to the encoder 100 than by using a general request signal.

[0057] [Effects Obtained by First Embodiment] The encoder 100 of the first embodiment includes a control unit 110, a non-volatile memory 120, a sensing unit 150 that detects the state of the device to be measured, a signal processing unit 160 that generates state detection information from the detection results of the sensing unit 150, and a communication unit 130 that communicates with an external controller 10. The memory 120 stores a one-rotation reset execution permission / prohibition setting value, the content of which is a reset execution permission setting or a reset execution prohibition setting. When the control unit 110 receives a transmission request signal from the controller 10 via the communication unit 130, the control unit 110 controls the signal processing unit 160 to transmit the state detection information generated by the signal processing unit 160 to the controller 10 via the communication unit 130. When the control unit 110 receives a setting request signal including the new one-rotation reset execution permission / prohibition setting value from the controller 10 via the communication unit 130, the control unit 110 controls the memory 120 to store the new one-rotation reset execution permission / prohibition setting value. When the control unit 110 receives a one-rotation reset request signal from the controller 10 via the communication unit 130, it controls so that a one-rotation reset is not executed if the stored one-rotation reset execution permission setting value is set to not permit reset execution, and so that a one-rotation reset is executed if the stored one-rotation reset execution permission setting value is set to permit reset execution. According to the encoder 100 described above, it is possible to change the setting in the non-volatile memory regarding whether or not to permit one-rotation reset execution from the controller 10 without using a setting device, and it is possible to appropriately execute a one-rotation reset.

[0058] In the encoder 100 of the first embodiment, the one-rotation reset execution permission setting value includes a reset execution permission setting or a reset execution non-permission setting. The reset execution non-permission setting further includes a changeable reset execution non-permission setting or an unchangeable reset execution non-permission setting. Such settings make it possible to select a state according to the application, such as appropriate execution of a one-rotation reset, prevention of erroneous execution of a one-rotation reset, execution of another one-rotation reset after preventing erroneous execution of a one-rotation reset, or permanent prevention of erroneous execution of a one-rotation reset.

[0059] In the encoder 100 of embodiment 1, when the new one-rotation reset execution permission setting value is a changeable reset execution permission setting, and when the stored one-rotation reset execution permission setting value is a non-changeable reset execution permission setting, the control unit 110 does not rewrite the stored one-rotation reset execution permission setting value. When the new one-rotation reset execution permission setting value is a changeable reset execution permission setting, and when the stored one-rotation reset execution permission setting value is a reset execution permission setting, the control unit 110 rewrites the stored one-rotation reset execution permission setting value to a changeable reset execution permission setting. Through such control, it is possible to appropriately rewrite the stored one-rotation reset execution permission setting value to the new one-rotation reset execution permission setting value, or not to rewrite it, depending on the stored one-rotation reset execution permission setting value.

[0060] In the encoder 100 of the first embodiment, when the new one-rotation reset execution permission setting value is set to reset execution permission and the stored one-rotation reset execution permission setting value is set to unchangeable reset execution permission, the control unit 110 does not rewrite the one-rotation reset execution permission setting value. When the new one-rotation reset execution permission setting value is set to reset execution permission and the stored one-rotation reset execution permission setting value is set to changeable reset execution permission, the control unit 110 rewrites the stored one-rotation reset execution permission setting value to reset execution permission. This control makes it possible to appropriately rewrite the stored one-rotation reset execution permission setting value to the new one-rotation reset execution permission setting value, or not to rewrite it, depending on the stored one-rotation reset execution permission setting value.

[0061] In the encoder 100 of the first embodiment, when the new one-rotation reset execution permission setting value is the unchangeable reset execution permission setting and the stored one-rotation reset execution permission setting value is the reset execution permission setting or the changeable reset execution permission setting, the control unit 110 rewrites the stored one-rotation reset execution permission setting value to the unchangeable reset execution permission setting. By such control, it becomes possible to appropriately rewrite the stored one-rotation reset execution permission setting value to the new one-rotation reset execution permission setting value according to the stored one-rotation reset execution permission setting value.

[0062] In the encoder 100 of the first embodiment, the control unit 110 has a function of responding to memory access from the controller 10 and writing data to a specified address in the memory 120. When the encoder 100 receives a one-rotation reset request signal in the memory access command format from the controller 10 via the communication unit 130, the encoder 100 writes the new one-rotation reset execution enable / disable setting value to the address in the memory 120. In this way, by using a request signal in the memory access command format, it is possible to communicate more information from the controller 10 to the encoder 100 than by using a general request signal.

[0063] In the encoder 100 of the first embodiment, when the power is turned on, the stored one-rotation reset execution permission setting value is read, and a determination is made as to whether or not to execute a one-rotation reset based on the read one-rotation reset execution permission setting value. This enables the encoder 100 to appropriately and reliably execute permission / prohibition of execution of a one-rotation reset based on the stored one-rotation reset execution permission setting value.

[0064] The measurement system 1 of the first embodiment includes a controller 10 that communicates with an encoder 100, and the encoder 100 that communicates with the controller 10. When the controller 10 transmits a transmission request signal to the encoder 100, the encoder 100 transmits state detection information to the controller 10 in response to the transmission request signal, and when the controller 10 transmits a setting request signal to the encoder 100 including a one-rotation reset execution permission / prohibition setting value whose content is a reset execution permission setting or a reset execution prohibition setting, the encoder 100 stores the one-rotation reset execution permission / prohibition setting value in a memory 120 in response to the setting request signal, and when the controller 10 transmits a one-rotation reset request signal to the encoder 100, the encoder 100 does not perform a one-rotation reset if the one-rotation reset execution permission / prohibition setting value stored in the memory 120 is a reset execution prohibition setting, and performs a one-rotation reset if the one-rotation reset execution permission / prohibition setting value stored in the memory 120 is a reset execution permission setting. According to the measurement system 1 described above, it is possible to change the settings in the non-volatile memory regarding whether or not to allow a one-rotation reset to be performed from the controller 10 without using any setting equipment, making it possible to properly perform a one-rotation reset.

[0065] 1 Measurement system, 10 Controller, 100 Encoder, 110 Control unit, 111 Request determination unit, 112 Signal processing controller, 113 Memory controller, 114 One-rotation reset determination unit, 115 One-rotation reset execution unit, 120 Memory, 130 Communication unit, 131 Receiving unit, 132 Transmitting unit, 150 Sensing unit, 160 Signal processing unit.

Claims

1. An encoder comprising: a control unit; a non-volatile memory; a sensing unit that detects the state of a device to be measured; a signal processing unit that generates state detection information from the detection results of the sensing unit; and a communication unit that communicates with an external controller, wherein the memory stores a one-rotation reset execution permission / prohibition setting value having a reset execution permission setting or a reset execution prohibition setting, and the control unit, upon receiving a transmission request signal from the controller via the communication unit, controls the state detection information generated by the signal processing unit to be sent to the controller via the communication unit, upon receiving a setting request signal from the controller via the communication unit including a new one-rotation reset execution permission / prohibition setting value, stores the new one-rotation reset execution permission / prohibition setting value in the memory, and upon receiving a one-rotation reset request signal from the controller via the communication unit, controls not to execute a one-rotation reset if the one-rotation reset execution permission / prohibition setting value stored in the memory is the reset execution prohibition setting, and controls to execute the one-rotation reset if the one-rotation reset execution permission / prohibition setting value stored in the memory is the reset execution permission setting.

2. The encoder according to claim 1, wherein the one-rotation reset execution permission setting value includes the reset execution permission setting or the reset execution non-permission setting, and the reset execution non-permission setting further includes a changeable reset execution non-permission setting or an unchangeable reset execution non-permission setting.

3. The encoder of claim 2, wherein the control unit, when the one-rotation reset execution permission setting value included in the one-rotation reset request signal is the changeable reset execution permission setting, does not rewrite the one-rotation reset execution permission setting value stored in the memory if the one-rotation reset execution permission setting value stored in the memory is the non-changeable reset execution permission setting, and rewrites the one-rotation reset execution permission setting value stored in the memory to the changeable reset execution permission setting if the one-rotation reset execution permission setting value stored in the memory is the reset execution permission setting.

4. The encoder of claim 2, wherein the control unit, when the one-rotation reset execution permission setting value included in the one-rotation reset request signal is the reset execution permission setting, does not rewrite the one-rotation reset execution permission setting value stored in the memory if the one-rotation reset execution permission setting value stored in the memory is the non-changeable reset execution non-permission setting, and rewrites the one-rotation reset execution permission setting value stored in the memory to the reset execution permission setting if the one-rotation reset execution permission setting value stored in the memory is the changeable reset execution non-permission setting.

5. The encoder of claim 2, wherein the control unit rewrites the one-rotation reset execution permission / prohibition setting value stored in the memory to the unchangeable reset execution prohibition setting if the one-rotation reset execution permission / prohibition setting value included in the one-rotation reset request signal is the unchangeable reset execution prohibition setting and if the one-rotation reset execution permission / prohibition setting value stored in the memory is the reset execution permission setting or the changeable reset execution prohibition setting.

6. The encoder of claim 1, wherein the control unit has a function of responding to memory access from the controller and writing data to a specified address in the memory, and when it receives the one-rotation reset request signal in a memory access command format from the controller via the communication unit, the request signal includes the new one-rotation reset execution enable / disable setting value and the address in the memory of the new one-rotation reset execution enable / disable setting value, the control unit writes the new one-rotation reset execution enable / disable setting value to the address in the memory.

7. The encoder according to claim 1, wherein the control unit reads the one-rotation reset execution permission setting value stored in the memory when power is turned on, and determines whether or not to execute the one-rotation reset based on the read one-rotation reset execution permission setting value.

8. A measurement system comprising: a controller that communicates with an encoder; and the encoder according to any one of claims 1 to 7 that communicates with the controller, wherein when the controller transmits a transmission request signal to the encoder, the encoder transmits status detection information to the controller in response to the transmission request signal; when the controller transmits a setting request signal to the encoder including a one-rotation reset execution permission / prohibition setting value whose content is a reset execution permission setting or a reset execution prohibition setting, the encoder stores the one-rotation reset execution permission / prohibition setting value in the memory in response to the setting request signal; when the controller transmits a one-rotation reset request signal to the encoder, the encoder does not execute the one-rotation reset if the one-rotation reset execution permission / prohibition setting value stored in the memory is the reset execution prohibition setting, and executes the one-rotation reset if the one-rotation reset execution permission / prohibition setting value stored in the memory is the reset execution permission setting.

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