Data transmission method between a primary master and primary slave via a bus line and between sub-slaves via the same bus line

Abstract

Method for digital, bidirectional data transmission between a position measuring system (3-7) and a motor control device (1) and/or an evaluation unit based on the transmission of frames (34, 35, 36) of a predefined bit length in chronologically sequential time slots (28-30), wherein a primary master (1) communicates via a two wire bus line (2) with the position measuring system (3-7) and/or the motor unit (11, 14) and/or the evaluation unit with a primary slave (3) disposed there, and that additional sub-slaves (12, 15) can be coupled in parallel to the primary slave (3), which sub-slaves communicate on the same bus line (2), which the primary master (1) uses with the primary slave (3).

Claims

1. Method for digital, bidirectional data transmission between a position measuring system and a motor control system and/or an evaluation unit based on the transmission of frames of a predefined bit length in chronologically sequential time slots, wherein a primary master communicates via a two wire bus line with the position measuring system and/or the motor unit and/or the evaluation unit with a primary slave disposed there, and that additional sub-slaves can be coupled in parallel to the primary slave, which sub-slaves communicate with the primary slave and each other on the same bus line that the primary master uses with the primary slave.

2. Method according to claim 1, wherein at least one sub-master is attached to the primary master on the same bus line.

3. Method according to claim 1, wherein the sub-slaves connected in parallel to the primary slave have sensor inputs and actuator outputs.

4. Method according to claim 1, wherein a first sub-master is parallel to the primary master and the first sub-master communicates with an internet based or device based cloud and supplies the data generated by the primary master to the cloud.

5. Method according to claim 4, wherein the sub-master carries out additional tasks, such as diagnostic tasks or making a gateway available, with which the sub-master supplies the data from the primary master to the internet, or to a LAN or a WLAN or to a mobile data system.

6. Method for digital, bidirectional data transmission between a position measuring system and a motor control system or an evaluation unit based on the transmission of frames of a predefined bit length in chronologically sequential time slots, wherein a cyclically repeating data frame consisting of at least three chronologically sequential time slots is available and that a primary master transmits and/or receives data in a first time slot, that the data response of the primary slave to the master is transmitted in a second time slot in the form of the time critical position data and that additional data are transmitted in the third time slot from a primary slave and/or sub-slaves that are attached in parallel thereto, wherein the primary slave and the sub-slaves communicate with each other in the third time slot.

Description

(1) The invention will be explained in greater detail in the following based on drawings depicting merely one execution path. In this connection, further features essential to the invention and advantages of the invention are derived from the drawings and the description thereof.

(2) The drawings show:

(3) FIG. 1: Block diagram of a first embodiment of a data transmission method according to the invention

(4) FIG. 2: A block diagram that has been modified as compared to FIG. 1 and is depicted with other modules

(5) FIG. 3: The time command diagram of the data transmission via the central bus line

(6) A control unit 20 is depicted generally in FIG. 1, in which a primary master 1 is disposed.

(7) The control unit 20 is disposed away from a motor housing, which in the depicted exemplary embodiment is comprised of a motor interior 11 and a motor environment 14.

(8) It is important that the connection between the control unit 20 and the modules 11, 14 is realized by a bus line 2, which is configured as a two wire bus line and via which the power supply is also provided for all slaves, sensors and other modules attached in the parts 11, 14.

(9) According to the invention, it is now provided that a secondary master 16 is connected to the primary master 1, which secondary master is also designated as the sub-master and which communicates directly with the bus line 2 of the primary master 1 via a bus line 2c.

(10) Said sub-master 16 carries out administrative tasks that are separate from the master 1 and makes available e.g., a USB interface, a LAN, a WLAN or a mobile interface link and is therefore in a position to communicate directly via the link 17 to a cloud 18.

(11) As a result, the primary master 1 is also able to directly upload its data to the cloud 18 via the link 21, in the same way as the sub-master 16 is able to via the link 17.

(12) Corresponding links can be available on the cloud 18, via which terminals 19 are triggered that analyze, process or optically display data that are generated on the control unit 20.

(13) In the opposite manner, it is also possible that a control software is made available on the terminal 19 side, and the terminals 19 are connected to the cloud via links in the cloud 18. This is suitable via the links 17, 21 to a direct data and command transmission on the primary master 1 and the sub-master 16 attached in parallel thereto.

(14) It is advantageous that the entire motor side 11, 14 can now be triggered via the central bus line 2, which consists preferably of a two wire bus line.

(15) The motor side consists of the motor environment 14, which can also be disposed outside the motor housing, and of the modules disposed in the motor interior 11. Sensors and/or actuators are preferably disposed in the motor environment.

(16) The exemplary embodiment according to FIG. 1 shows that a primary slave 3 in which a rotary encoder is implemented is now disposed in the interior of the motor 11 in a manner that is known per se.

(17) All other modules required for data processing and data transmission are also disposed in said primary slave 3, such as e.g., a position module 4, which can have a redundant channel 37 if necessary and an associated status module 5 and other modules, which can be configured e.g., as input or output modules 6, 7.

(18) The result of this is that the primary slave 3 is able to trigger an actuator or a plurality of actuators 9 via a signal path 8 and, conversely, one or a plurality of sensor inputs of sensors 13 can be present which carry out a data exchange with the primary slave 3 via the signal path 10.

(19) The invention now provides that further sub-slaves are henceforth assigned to the primary slave 3, all of which are connected in parallel and are able to communicate with the primary slave 3 via corresponding branches of the central bus line 2, but also directly with the primary master 1.

(20) Thus, the exemplary embodiment according FIG. 1 shows that a sub-slave 12 can also be disposed in the motor interior 11, which generates, processes and forwards e.g., additional data in the motor interior. This type of data could be e.g., the motor temperature, humidity, vibration and the like.

(21) Said sub-slave also has the signal path 8 to actuators 9a and sensors 13a to be triggered, which transmit data to the sub-slave 2 via the signal path 10.

(22) As further exemplary embodiment, FIG. 1 shows that another sub-slave 15 can also be connected in parallel to sub-slave 2, which is then preferably located outside the motor interior 11, specifically e.g., in the environment of the motor.

(23) In this regard, it can be machine data, which is collected outside the motor by the sub-slave 15, such as e.g., temperature, humidity, vibration and other data that are derived directly from the machine in which the motor is installed.

(24) In this case as well, the invention provides that actuators 9b are triggered by the signal path 8 and, conversely, a plurality of sensors 13b supply data to the sub-slave 15 via the signal path 10.

(25) The division of the transmission protocol into a total of three time slots ensures that not only two sub-slaves 12, 15 can be connected in parallel, but a plurality of other sub-slaves, which are not depicted for the sake of comprehensiveness.

(26) In comparison to FIG. 1, FIG. 2 shows approximately the same structure, where is evident that the primary master 1 and a sub-master 16 connected in parallel thereto are located on the right side, and the cited masters are connected to each other via a bus line 2c branching off from the central two wire bus line 2.

(27) The simplified depiction in FIG. 2 shows merely the interface of the respective masters 1, 16 and other interface circuits, without providing any details about the electrical components.

(28) According to one feature of the invention, it can also be provided, however, that the bus line that is configured as a two wire bus line 2 can also be configured as a four wire bus line, wherein two wires are used for the control commands and two other wires for the power supply.

(29) This applies not just to the bus line 2, but also to the bus lines 2a, 2b, 2c attached thereto.

(30) Moreover, it can be provided in another embodiment of the invention that the central bus line 2 is configured in a two wire or four wire design and, in a similarly deviating manner, the bus lines 2a, 2b, 2c attached thereto are likewise configured, optionally and in any combination thereof, as two wire or four wire bus lines.

(31) The slaves 3, 12, 15 are depicted in the center portion of FIG. 2 only in a schematic representation and it is evident that said slaves are also connected to each other via the two wire or the four line bus line 2a, 2b and can also communicate with each other.

(32) A sensor module 22 is thereby disposed at the output of the primary slave 3, in which the time critical rotary encoder is disposed, wherein said primary slave may communicate in time slot 2 (DTF 1).

(33) A line 24 is provided for this purpose.

(34) The additional sensor module 22a is connected to the secondary slave 12 via another line 24 and includes for example sensors for the detection of the vibration, the temperature, the humidity and other physical parameters and is provided in order to communicate only in time slot 3, specifically in DTF 2.

(35) The third sub-slave 15 is coupled to another sensor module 23 via another line 24, and in this case, it is provided that the sensor module 23 communicates only in the third time slot DTF 2. Such communication relates e.g., to checking the connecting cable, detecting the vibration, temperature and other parameters, which may be present in the motor interior or in the machine interior or in the outer area.

(36) In principle, FIG. 2 also partially depicts the prior art, which is explained based on the dividing line 25.

(37) Everything above the dividing line 25 in arrow direction 26 is in principle an arrangement of the prior art, and the invention lies therein that said prior art is continued on the other side of the dividing line 25, and specifically downwards in arrow direction 27, where it can be seen that, according to the invention, a plurality of sub-masters are now assigned to the primary master, and that one or a plurality of sub-slaves 12, 15 are likewise assigned to the primary slave 3 on the motor side.

(38) FIG. 3 shows the time command diagram in which data transmission, originating from the primary master 1, makes a master request frame (MRF) available in time slot 28 (time slot 1) according to FIG. 3.

(39) Five different types of commands are depicted among each other in FIG. 3 on the abscissa, wherein, in example (1), a primary master command 34 is generated by the primary master 1 and transmitted via the central bus line 2.

(40) It is a standard command, with which the position data for example are requested and in time slot 2 (reference sign 29), DTF1, the primary slave may then respond with a primary slave response 35.

(41) The second time slot 29 extends from time point 31 to time point 32 and, upon completion of said time period, the third time slot 30 begins, in which a further data transmission takes place. The primary slave response 36 is transmitted e.g., in time slot 3 and relates to the data that are transmitted as a copy or an error correction takes place.

(42) Upon completion of time slot 3 (DTF2) at time point 33, the process repeats cyclically and the primary master 1 transmits its master command via the MRF.

(43) In the exemplary embodiment according to (2) in FIG. 3, the primary master transmits in time slot 1 the request to convey safety data, which means that the position data are requested from a redundant channel of the rotary encoder and the primary slave responds with the primary slave response 35 in time slot 2.

(44) Upon completion of the transmission in time slot 2, a transmission of data takes place in time slot 3 (30), wherein e.g., the safety data are transmitted in a redundant channel 37 and the primary slave response 36a takes place.

(45) In the exemplary embodiment according to FIG. 3 in accordance with (3), a “Read Data” command is generated by the primary master 1 in the MRF and the requested data are transmitted in time slot 2 in the primary slave response.

(46) Then, in time slot 3 the additional data are transmitted, such as e.g., OEM data, diagnostic data or status data, wherein said data are transmitted by the respective sub-slave that is addressed by the master. This can be a primary slave, but also the sub-slaves 15.

(47) In the exemplary embodiment according to (4) in FIG. 3, a write command is generated by the primary master in the MRF, and the addressed slave responds in time slot 3 with an acknowledgement command.

(48) In the exemplary embodiment according to (5), a so-called MSRD command is transmitted. The abbreviation means “Send Request Data with Multicast Replay data exchange broadcast (slave cross traffic)”.

(49) This means that during the generation of the primary master command 34, the primary slave responds in the normal manner with its position data, but that, in the second time slot (30), the cross traffic between the slaves is initiated, in that a corresponding command is transmitted and the slaves and sub-slaves can now exchange data with each other. It can also be provided that, after a data exchange has taken place, sub-slaves that exchanged their data with each other transmit an acknowledgement to the primary master.

(50) Furthermore, it can be provided that the slaves carrying out the data exchange slaves do not communicate with the primary master, rather with the secondary master 16.

(51) For example, the following data of the primary slave are transmitted in time slot 2 (29): 1. Multiturn information 2. Singleturn information 3. Live counter 4. Checksum CRC

(52) According to the exemplary embodiment (1), the following data are generated in the third time slot (30): 1. Copy of the first data 2. Multiturn 3. Singleturn 4. Live counter 5. CRC 6. Additional status information 7. All data, all of which are used for a possible error correction.

(53) A typical value of 31.25 microseconds is indicated as a time interval between the start of the first time slot 28 and the end of the cyclic data transmission at position 33.

(54) As a result, data repetition rates of 32 KHz, 16 or 8 KHz are achieved depending on the configuration.