JPH03232001A - Synchronous positioning unit - Google Patents

Abstract

PURPOSE:To perform the synchronous operation of plural groups simultaneously by correcting the error of the travel distance of each axis at a frequency division circuit, and supplying an alarm to a selection gate when the accumulated number of pulses of a deviation counter in a deviation over exceeds a preset value. CONSTITUTION:The control part 1 of the synchronous positioning unit of each axis immediately responds to a start signal, and outputs a command pulse to the selection gate 23 with the same timing possibly. The command pulse outputted from the selection gate 23 is sent to the deviation counter 5, and the accumulated number of pulses in the deviation counter 5 is converted to an anlog signal with a D/A converter 6, and is sent to a driver for motor driv ing as a speed command. The frequency division circuit 25 corrects delicately different errors in the travel distance, and the deviation over 27 checks the accumulated number of pulses in the deviation counter 5, and sends the alarm to the selection gate 21 when it exceeds the preset value. Thereby, it is possible to perform the synchronous operation of the plural groups simultaneously with out giving any limitation.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to A in the field of stage mechanisms, general industrial machinery, etc.
C servo motor, DC servo motor 1. Conventional techniques and problems related to synchronous positioning control method for multiple axes such as inverters [Conventional techniques and problems] Conventionally, when synchronous positioning control requires high-precision followability, digital servo control equipment for axles is controlled by 4. I actually saw it by modifying it and combining it, or by using a multi-axis controller that allows one CPU to control multiple servo motors at the same time.

These systems have had to limit the number of axes due to processing time and wiring distance issues, and have been used for applications where the number of systems is relatively small, such as 8 axes or less. In other words, as the number of axes increases, the accuracy of tracking has to be sacrificed.

On the other hand, in fields such as the above-mentioned stage equipment, synchronized operation of about 100 axes of suspension mechanisms and pressing mechanisms is required, and synchronized operation of eight or more axes is also required in transfer devices for production lines and processing lines. In addition, not only a predetermined number of axes perform synchronous operation, but also an arbitrary group from among all axes is selected each time to perform synchronous operation, or the other group descends while the own group ascends. Multiple groups are required to perform synchronous operation at the same time.

The purpose of the present invention is to meet the various demands mentioned above.
It is an object of the present invention to provide a positioning controller capable of ranging from independent operation to synchronized operation of eight or more axes.

[Means to solve the problem]

The synchronous positioning unit of the present invention includes a means for generating a command pulse signal for positioning based on parameters such as travel distance, speed, acceleration/deceleration time, etc. given from an external host computer, and a means for generating a command pulse signal for positioning by passing the command pulse signal to the outside via a selection gate. a means for outputting the command pulse signal to the external bus, a means for internally taking in the command pulse signal outputted by another synchronous positioning unit input from the external bus via a selection gate, and a means for inputting the command pulse signal that has been taken in according to a given ratio. A means for dividing the frequency of a position feedback pulse sent from a pulse generator attached to a motor shaft or a machine by a given ratio, and outputting the position feedback pulse to an external bus via a selection gate. means for internally taking in position feedback pulses output from other synchronous positioning units input from an external bus via a selection gate; and means for frequency-dividing the taken-in position feedback pulses by a given ratio. Three signals: a command pulse signal generated by itself, a command pulse signal input from an external bus and frequency-divided, and a position feedback pulse input from an external bus and frequency-divided. means for selecting the output pulse of the deviation counter from the output pulse; means for using the deviation between the output pulse and its own frequency-divided position feedback pulse as a speed command; and its own frequency-divided position feedback pulse and a means for inputting it from an external bus and using the deviation of the frequency-divided position feedback pulse of another synchronous positioning unit as speed correction via a selection gate; Other synchronous positioning input from the bus and frequency divided y]
A means of detecting the deviation as exceeded when the deviation of the unit's position feedback pulse exceeds a certain set value, and the amount of the set value with the droop pulse of the own deviation counter.
A means to detect the deviation as <- when it becomes -, a means to detect an abnormality through self-diagnosis such as self-memory check and Wofchi dog, and a driver connected to itself that drives the motor according to a speed command. A means for inputting external abnormalities such as, a means for outputting these deviation exceedances and abnormalities as alarm signals to an external bus via a selection gate, and an alarm signal input by the own alarm signal and an external bus It has a means for making an emergency stop by means of an external bus, and a means for making a positioning start using a start signal sent from an external bus so that predetermined groups can start simultaneously at high speed.

[Effect]

FIG. 1 shows the configuration of a synchronous positioning unit.

The speed command is output via the D/A 6 and drives the AC servo motor, DC servo motor, and inverter motor. In addition, instructions are given from a higher-level computer connected via the operation pattern sequential output unit 2.

Since one unit controls one fixed axis,
Units for the required number of axes are prepared in advance.

When high-precision synchronization is required, first, a mask unit serving as a reference for synchronization is determined in a group selected for synchronized operation of all axes. Once the mask is determined, other units become slaves that follow the mask. The host computer determines whether the synchronous positioning unit operates as a mask or a slave.

The control unit 1 of the synchronous positioning unit, which serves as a mask, determines an operation pattern from parameters such as travel distance, speed, acceleration/deceleration time, etc. sent from the host computer, and outputs pulses via the command pulse generator 4 for the travel distance, with the period as the speed. do. This command pulse is sent to its own deviation counter 5, and is also sent to the deviation counter 5 of the slave synchronous positioning unit via external bus A or bus B, and is D/A converted by D/Δ6. , is output to the motor drive driver as a speed command.

Pulses corresponding to the distance moved are input from the position detection encoder, fed back to the deviation counter 5, and sent from the mask to the slave synchronous positioning unit via an external bus C or bus D.

Errors in the moving distance due to subtle differences in the degree of stretch of the belt of each axis, the string of the hanging device, etc., and the gear ratio can be adjusted for each axis by the frequency dividing circuit 25.

The slave synchronous positioning unit obtains the reference current value 8 from the position feedback pulse sent from the mask via bus C or bus D, and calculates the current feedback pulse value 7 calculated from its own corrected position feedback pulse. compare. This deviation is ORed with the output of the deviation counter 5 and inputted to the D/A 6 to correct the speed.

Depending on the system, such speed correction may have the opposite effect, such as causing hunting. Therefore, in the comparison 10 for determining the deviation between the feedback current value 7 and the reference current value 8, the gain ratio may be changed, or the deviation may be calculated unless the deviation exceeds a certain amount. Processing such as creating a dead zone is performed to prevent output.

With the above-described method, highly accurate tracking can be achieved in distance synchronization in which positioning is performed over the same distance at the same time.

On the other hand, in the case of time synchronization in which different distances are positioned at the same time, the synchronized positioning unit of the axis that is the fastest is selected as the mask. In the slave synchronous positioning unit, the frequency is divided by the bus frequency dividing circuits 24 and 26 according to the ratio of the moving distance to the master based on the command from the mask sent via the external node Δ or B. Other operations are basically the same as in distance synchronization.

Furthermore, although the above operation has been explained as a case where the slave is synchronized with the command pulse of the mask, in the synchronous positioning unit serving as the slave, the command pulse to be sent to the deviation counter 5 is switched from the mask to the external bus C or by switching the selection gate 23. The position feed sent via NoxD can be set as <)res. This method synchronizes with the distance that the mask axis actually moves, so it is possible to further improve followability with the mask.

In the method of following the mask position feedback pulse, the selection between distance synchronization and time synchronization is made by the frequency dividing circuit 26. If the frequency division ratio of the frequency dividing circuit 26 is set to 1:1, distance synchronization will be achieved, and if the frequency division ratio is set according to the ratio of the moving distance to the fastest mask, time synchronization will be achieved. The frequency division ratios of the frequency dividing circuits 24 to 26 can be freely set from the host computer.

Up to now, we have described the cases of synchronization with the command pulse of the mask and the case of synchronization with the position feedback pulse, but as another synchronization method, by switching the selection gate 23, the control units of each axis can be started simultaneously and the control units can be synchronized within the same time. You can choose how to send command pulses to your own deviation counter. In this case, the accuracy of tracking is lower than in the above two cases due to variations in the scan of the CPU of each axis, but it has the advantage that multiple groups can operate synchronously at the same time without limit. In the present invention, as a means to improve the accuracy of the above-mentioned method, an external start signal bus E is prepared, and other axes directly input the start signal outputted from an arbitrary axis via the bus E, so that at least a number of It is possible to start dispensing command pulses within m5ec.

If the travel distance, acceleration/deceleration time, and travel time are set in advance from the host computer, the control unit 1 of each axis will start and stop at the same timing.
The speed is automatically calculated and transmitted to the command pulse generator 4.

In this case, distance synchronization is achieved if the moving distances are the same, and time synchronization is achieved if the moving distances are different.

Further, there is no relationship between mask and slave except for outputting a start signal.

When performing synchronous operation, it is necessary to consider what to do if one of the axes stops due to an emergency situation. Various cases can be considered, such as stopping all axes as soon as possible in some cases, and continuing to operate other axes in other cases. This is selected in the selection game) 21.

Emergency situations are detected by over deviation 27.28 and self-diagnosis 11. Deviation over 27 is deviation counter 5
An alarm is issued when the accumulated pulses exceed a certain set value. For deviation over 2B, the comparison 10 checks the deviation between the feedback current value 7 and the reference current value 8, and issues an alarm if the deviation exceeds a certain set value. The self-diagnosis 11 issues an alarm through self-diagnosis such as a memory check and a watchdog performed by the control unit 1. A selection gate 21 determines whether or not these alarms are output to an external bus F, which is an alarm bus.

The deviation over 27 is mainly used by a synchronous positioning unit serving as a mask, or in the case where the above-mentioned axes start at the same time and output command pulses to their own deviation counters. The deviation over 28 is used in a synchronous positioning unit that becomes a slave in the case of following a mask command pulse or a position feedback pulse.

The selection gate 22 is provided to select whether to simultaneously start or make an emergency stop based on a start signal or an alarm signal sent from an external bus.

FIG. 2 shows one bus connection example as a method of connecting buses A to F. A maximum of 30 units can be connected, but by connecting repeaters one after another as shown in Figure 3, 30 units can be connected.
Zero or more synchronous positioning units can be mounted on one transmission line. In addition, since the human output interface between Bus A to Bus F and the host computer is separated, buses A to Bus F of the synchronous positioning unit controlled by multiple host computers can be connected through a single transmission line to achieve synchronization. Able to drive.

Further, an input is provided before the deviation counter 5 that can receive pulses from a manual pulse generator. It is added to the command pulse from the selection gate 23 and input to the deviation counter 5, allowing manual correction of the moving distance. When there is no command pulse from the selection gate 23, it is also possible to operate with only the signal from the manual pulse generator.

It also has an override function that allows the host computer to set the speed to the control unit 1 so that the speed can be changed during automatic operation.

Information such as each current value, the contents of the deviation counter, and the current value commanded to the deviation counter can also be read from the host computer.

In addition, two types of interfaces with the host computer are available: one using a parallel bus method and one using communication.

An absolute type encoder or an incremental type encoder can also be used as an external position detection encoder.

It also has an S-time acceleration/deceleration function for cushion start and cushion stop.

〔Example〕

Embodiments of the present invention will be described for each case with reference to the drawings.

Case 1: When synchronizing with the master's command pulse FIG. 4 shows an example in which each axis follows the mask's command pulse as a reference signal for positioning. The synchronous positioning unit 1 becomes a mask, and the synchronous positioning unit 2 and other units become slaves. The operation of the slave will be explained using the synchronous positioning unit 2 as a representative.

The following steps will be explained.

(Step 1) First, the host computer has input/output section 2, 2-port RAM 3
The controller 1 specifies whether the control unit 1 of each synchronous positioning unit is a mask or a slave.

The host computer transmits parameters such as travel distance, acceleration/deceleration time, speed, etc. to the synchronous positioning unit 1 that serves as a mask to the control unit 1 via the input/output unit 2, 2 ports) RAM 3, and also sends command pulses that serve as the reference for the mask. The ratio of the moving distance to the frequency dividing circuit 241, that is, the frequency division ratio of the frequency dividing circuit 26 is transmitted to the control unit 1 via the input/output unit 2° (2 baud) RAM 3 to the synchronous positioning unit 2 serving as a slave. At this time, if the moving distance ratio is 1:1, distance synchronization is achieved, and if it is 1:1/N, time synchronization is achieved.

(Step 2) The host computer sends a start signal to the control unit 1 via the human output unit 2, 2 and RAM 3 to the synchronous positioning unit 1 serving as a mask, and starts synchronous operation.

(Step 3) The command pulse generation 4 of the synchronous positioning unit 1 serving as a mask outputs a command pulse to the selection gate 23 with the synchronization as the speed and the number of pulses as the moving distance.

It also outputs a command pulse to the bus A via the selection game (13).

The synchronous positioning unit 2 serving as a slave sends the command pulse input from the bus 8 to the frequency dividing circuit 24 via the selection gate 14. The frequency dividing circuit 24 divides the frequency of the command pulse according to a preset movement distance ratio and sends it to the selection gate 23.

The command pulse output from the selection gate 23 is sent to the deviation counter 5, and the amount of droop pulses in the deviation counter 5 is converted into an analog signal by the D/A 6 and sent to the motor drive driver as a speed command, which is common to both the mask and the slave. This is an action to do.

Further, the amount of movement of each axis is fed back from the position detection encoder via the encoder interface 9.

The frequency dividing circuit 25 is for correcting errors in the slightly different moving distances of each axis.

The position feedback pulse passed through the frequency dividing circuit 25 is sent to the feedback current value 7 and the deviation counter 5.

The position feed bank pulse of the synchronous positioning unit 1 serving as a mask is outputted to the bus C via the selection gate 17.

The synchronous positioning unit 2 which becomes the slave is the selection game [9
Input position feed bank pulse from bus C via [
7) -C frequency dividing circuit 2 according to the set moving distance ratio
(After dividing the frequency by 4, send it to the quasi-current value 8.

Also, in the comparison 10, the deviation between the feedback current value 7 and the reference current value 8 is calculated and the deviation is added to the output of the deviation counter 5 as a speed correction. This signal is sent to the selection gate 21 as an alarm.

In the synchronous positioning unit 1 serving as a mask, when the accumulated pulses of the deviation counter 5 exceed a certain set value due to an excess deviation 27, an alarm is sent to the selection gate 21.

As a result of these alarm signals and the self-diagnosis of each axis, the determined alarm signal is sent to the bus F via the selection game (21).

Each synchronous positioning unit is connected to a selection gate 22 from bus F.
An emergency stop can be performed all at once by an alarm signal input via the .

Furthermore, if it is not the alarm signal of the driver's own, the driver can ignore it 17 and continue driving.

The command pulse output from the command pulse generator 4 of the mask passes through the bus B via the selection gate 15 instead of the selection gate 13, and in the slave, it passes through the selection gate L6 instead of the selection gate 14 to the frequency dividing circuit. It is also possible to input the information to 24.

In addition, the position foot pulse inputted via the frequency dividing circuit 25 of the mask passes through the bus D via the selection gate 8 instead of the selection gate 17, and passes through the selection gate 20 instead of the selection gate 19 in the slave. , frequency dividing circuit 26
It is also possible to input the information into

As mentioned above, since there are buses Δ and bus B for command pulses, and buses C and D for position feedback pulses, up to two groups can be operated synchronously at the same time.

FIG. 5 shows an example of tracking each axis using a mask position feedback pulse as a reference pulse for positioning.

The synchronous positioning unit 1 serves as a mask, and the synchronous positioning unit 2 and other units serve as slaves. The operation of the slave will be explained using the synchronous positioning unit 2 as a representative.

The following steps will be explained.

(Step 1) First, the host computer has input/output section 2, 2-port RAM 3
The controller 1 specifies whether the control unit 1 of each synchronous positioning unit is a mask or a slave.

(Step 2) The host computer 2 transmits parameters such as travel distance, acceleration/deceleration time, and speed to the synchronous positioning unit 1, which serves as a mask, to the control unit 1 via the human output unit 2.2 and RAM 3. , the ratio of the moving distance to the reference command pulse of the mask, that is, the frequency dividing ratio of the frequency dividing circuit 26, is transmitted to the input/output unit 2, which is the slave synchronous positioning unit 2.
The information is transmitted to the control unit 1 via the 2-point RAM 3. At this time,
When the speed ratio becomes 1:1, distance synchronization occurs, and when the speed ratio becomes l:1/H, time synchronization occurs.

(Step 3) The host computer sends a start signal to the control unit 1 via the human output unit 2.2 point RΔM3 to the synchronous positioning unit 1 serving as a mask, and starts synchronous operation.

The command pulse generation 4 of the synchronous positioning unit 1 serving as a mask outputs a command pulse to the selection gate 23 with the cycle as the speed and the number of pulses as the moving distance.

Further, the command pulse output from the selection gate 23 is sent to the deviation counter 5, and the accumulated pulse of the deviation counter 5 is D/A.
The position feedback pulse sent from the position detection encoder to the synchronous positioning unit (one master) is converted into an analog signal by the encoder interface 9 and sent to the motor drive driver as a speed command. It is input to the feedback current value 7 and the deviation counter 5 via the circuit 25.

It also outputs a position drop pack pulse to the bus C' via the selection game 11.7.

The slave synchronous positioning unit 2 selects the position feedback pulse input from the bus C1 through the gate 19.
The signal is sent to the frequency divider circuit 26 via. The frequency dividing circuit 26 divides the frequency of the position feedback pulse according to a preset speed ratio and sends it to the selection game 23 and the reference current value 8.

the command pulse sky deviation counter 5 that has exited the selection gate 23;
It is the same as Mask 7 that is output as a speed command to the motor drive driver via D/A 6, and
The position feedback pulse from the position detection encoder is passed through the encoder interface 9 and the frequency dividing circuit 25.
Also, the current feedback value 7 and the input to the deviation counter 5 are exactly the same as the mask.

The frequency dividing circuit 25 for both the mask and the slave is used to correct errors in the slightly different moving distances of each axis.

In the positioning unit 2 serving as a slave, the deviation between the feedback current value 7 and the reference current value 8 is calculated at a comparison angle of 1°, and the deviation is added to the output of the deviation counter 5 after compensating, and the setting is made to include the deviation. When the value exceeds the value, an alarm is sent to the selection gate 21 due to deviation over 28.

In the synchronous positioning unit 1 which becomes 7 stars, the deviation counter 5 accumulates due to excess deviation 27; - When the input reaches a certain set value 1-, an alarm is set to i'A selection 21.
5, - these alarm signals and each axis (, -\
The result of rV diagnosis, the determined alarm signal is selected
'-)2+ to bus F.

Each synchronous positioning coat can be brought to an emergency stop all at once by an alarm signal inputted from bus F through select gate 22.

Also, if the alarm signal is not your own, you can ignore it and continue driving.

Note that the position feedback pulse sent from the mask to the slave may pass through the bus D via the selection gate 18 instead of the selection gate 17, and be input to the frequency dividing circuit 26 via the selection gate 20 instead of the selection gate 9. It is possible.

As mentioned above, bus C is used for position feedback pulses.
, bus D, so up to two groups can perform synchronous operation at the same time1. In Figure 6, the control unit 1 of each axis generates command pulses at the same time and positions at the same time. This shows an example of synchronization using this method.

In this embodiment, the relationship between mask and slave does not hold.

Each synchronous positioning unit basically performs the same operation.

The steps will be explained below.

(Step 1) First, the host computer is the human output section 2□ 2-port RA
Parameters such as travel distance, acceleration/deceleration time, and the same travel time for all axes are sent to the control unit 1 via M3.

(Step 2) The control unit 1 calculates the speed for moving in the same time from the parameters sent from the L computer. If the travel distances are the same, distance synchronization will occur, and if travel distances are different, time synchronization will occur.

(Step 3) The host controller selects one of the synchronous positioning units that perform synchronous operation, and inputs and outputs the input/output section 22 boat RAM.
3. The control unit 1 outputs a start signal to the external bus E via the output 12.

The control section 1 of the synchronous positioning unit for each axis quickly responds to the start signal input from the bus E via the selection gate 21, and outputs command pulses to the selection gate 23 at the same timing as possible.

The command pulse output from the selection gate 23 is sent to the deviation counter 5, and the amount of droop pulses in the deviation counter 5 is converted into an analog signal by the D/A 6 and sent to the motor drive driver as a speed command. The position feedback pulse from the position detection encoder is input to the feedback current value 7 and the deviation counter 5 via the encoder interface 9 and the frequency dividing circuit 25.

The frequency dividing circuit 25 is for correcting errors in the slightly different moving distances of each axis. When the deviation exceeds 27, the accumulated pulses of the deviation counter 5 are checked, and if it exceeds a certain setting, an alarm is sent to the selection gate 2j. In addition, the results of self-diagnosis such as memory check and wonch dog,
The determined alarms are also sent to the selection gate 21, and these alarm signals are output to the bus F.

Each synchronous positioning unit can be brought to an emergency stop all at once by an alarm signal inputted from the bus F through the selection gate 22.

Also, if the alarm signal is not your own, you can ignore it and continue driving.

In case 3, multiple groups can perform synchronous operation simultaneously without restrictions.

Although the above-described operations and embodiments have been described with respect to output using a high-speed command analog signal, they can also be applied to a method of output using a pulse cycle.

Further, it can also be applied to a system in which the present invention is combined into a unit that is combined with a motor drive driver.

In addition, the explanation was given using an example in which two external buses are prepared for transmitting command pulses and position feedback pulses, but by preparing three or more buses, simultaneous operation of multiple groups in case 1 or case 2 is possible. The number of groups that can be created can be increased.

The unit of the present invention can be used as a single unit, and can be used not only in synchronous operation but also in independent operation.

[Effects of the Invention] As explained above, according to the present invention, not only synchronized operation is possible by accurately following a specified axis and starting at the same time, but also it is possible to perform synchronized operation by any group. multiple groups can be selected and multiple groups can perform synchronous operation at the same time.

Therefore, when controlling stage equipment that uses nearly 100 axes of motors, it is possible to achieve functions such as synchronized operation of multiple groups in various combinations or in the same scene at the same time, resulting in even greater production effects. It becomes like this.

Furthermore, the present invention can greatly benefit when synchronous operation of multiple axes is required in transfer devices for production lines and processing lines in the general industrial field.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the synchronous positioning unit of the present invention, and FIG. 2 is a bus A for pulse signal transmission of the present invention.
~A configuration diagram of bus F, Figure 3 is a configuration diagram showing how to expand the pulse signal transmission bus, Figure 4 is a block diagram of the case synchronized with the mask command pulse, and Figure 5 is a block diagram of the case in which the pulse signal transmission bus is synchronized with the mask command pulse. Block diagram of synchronization. FIG. 6 is a block diagram of the case of synchronization with a simultaneous start signal. 1... Control section 2... Input/output section 3
...2 baud) RAM 4 ... Command pulse generation 5 ... Deviation counter 6 ... D/A 7 ... Feedback current value 8・・・・・・Reference current value 9 ・
...Encoder interface 10...
Comparison 11... Self-diagnosis 12...
・Output 13, 14.15.16...Selection gate 17,
18.19.20... Selection gates 21, 22.
23... Selection gate 24, 25.26...
... Frequency divider circuit 27, 28 ... Deviation exceeded

Claims (1)

[Claims] Means for generating a command pulse signal for positioning based on parameters such as travel distance, speed, acceleration/deceleration time, etc. given from an external host computer, and means for generating the command pulse signal from an external host computer via a selection gate. A means for outputting the command pulse signal to the bus, a means for internally taking in the command pulse signal outputted by another synchronous positioning unit input from the external bus via a selection gate, and a means for dividing the taken command pulse signal according to a given ratio. means for dividing the position feedback pulse sent from a pulse generator attached to the motor shaft or the machine by a given ratio; and outputting the position feedback pulse to an external bus via a selection gate. means for internally capturing position feedback pulses output from other synchronous positioning units input from an external bus via a selection gate; and means for dividing the frequency of the captured position feedback pulses according to a given ratio. , the deviation from three signals: the command pulse signal generated by itself, the command pulse signal input from an external bus and frequency-divided, and the position feedback pulse input from an external bus and frequency-divided. means for selecting the output pulse to the counter; means for using the deviation between the output pulse and its own frequency-divided position feedback pulse as a speed command; and its own frequency-divided position feedback pulse. Means for inputting from an external bus and using the deviation of frequency-divided position feedback pulses of other synchronous positioning units as speed correction via a selection gate; A means for detecting an excess deviation when the deviation of the position feedback pulses of other synchronous positioning units input from the bus and frequency-divided exceeds a certain set value, and a setting with a droop pulse of the own deviation counter. A means for detecting deviation exceeded when the value exceeds a value, a means for detecting an abnormality through self-diagnosis such as self-memory check and watchdog, and a driver that drives a motor according to a speed command connected to itself. A means for inputting external abnormalities of the controller, a means for outputting these deviation exceedances and abnormalities as alarm signals to an external bus via a selection gate, and a means for inputting an alarm signal of own alarm signal and an alarm signal input from an external bus. It consists of a means for emergency stop, a means for arbitrarily outputting a start signal to an external bus, and a means for positioning start using a start signal sent from an external bus so that predetermined groups can start simultaneously at high speed. , a synchronous positioning unit that provides positioning control such as distance synchronization, which positions the same distance at the same time, and time synchronization, which positions different distances at the same time.