Increment pulse coder

Rotary position measuring element, mounted on the motor shaft or ball screw, sends out pulses at equal intervals when rotating to indicate displacement. Because there is no memory element, it cannot accurately represent the position of the machine tool. Only after the machine tool returns to zero and the zero point of the machine tool coordinate system is established, can the position of the worktable or tool be displayed. It should be noted that there are two ways of signal output of incremental encoder: serial and parallel. Individual numerical control systems correspond to this with serial interface and parallel interface.

Absolute pulse coder

The rotary position measuring element has the same purpose as the incremental encoder, with a memory element that can reflect the actual position of the machine tool in real time. The position after shutdown will not be lost, and the machine tool can be put into processing operation immediately without returning to the zero point after it is turned on. As with incremental encoders, attention should be paid to the serial and parallel output of pulse signals when using it.

 

 

 

 

 

 

 

 

Orientation

In order to perform spindle positioning or tool change, the machine spindle must be positioned at a certain corner in the circumferential direction of rotation as the reference point of the action. Generally there are the following 4 methods: orientation with position encoder, orientation with magnetic sensor, orientation with external one-turn signal (such as proximity switch), orientation with external mechanical method.

Double drive control (Tandem control)

For large workbenches, when the torque of one motor is not enough to drive, two motors can be used to drive together. One of the two axes is the driving axis and the other is the driven axis. The master axis receives the control command from CNC, and the slave axis increases the driving torque.

Rigid tapping

The tapping operation does not use a floating chuck but is realized by the rotation of the spindle and the synchronized operation of the tapping feed axis. The spindle rotates once, and the feed of the tapping axis is equal to the pitch of the tap, which can improve the accuracy and efficiency. Metal processing WeChat, the content is good and worthy of attention. To realize rigid tapping, a position encoder (usually 1024 pulses/revolution) must be installed on the spindle, and the corresponding ladder diagram must be compiled and related system parameters set.

Tool compensation memory A, B, C (Tool compensation memory A, B, C)

Generally, the tool compensation memory can be set to any one of A type, B type or C type with parameters. Its external performance is: Type A does not distinguish between the tool geometry compensation and wear compensation. Type B separates geometry compensation and wear compensation. Type C not only separates geometry compensation from wear compensation, but also separates tool length compensation code and radius compensation code. The length compensation code is H and the radius compensation code is D.

DNC Operation (DNC Operation)

It is a way of working automatically. Connect the CNC system or computer with RS-232C or RS-422 port. The processing program is stored on the hard disk or floppy disk of the computer, and inputted to the CNC piece by piece. Each time a piece of program is input, one piece is processed. This can solve the limitation of CNC memory capacity.

Advanced preview control (M)

This function is to read in multiple blocks in advance, interpolate the running track and preprocess the speed and acceleration. In this way, the following error caused by acceleration, deceleration and servo lag can be reduced, and the tool can more accurately follow the part contour of the program command at high speed, which improves the machining accuracy. Pre-reading control includes the following functions: linear acceleration and deceleration before interpolation; automatic deceleration at corners and other functions.

Polar coordinate interpolation (T)

Polar coordinate programming is to change the Cartesian coordinate system of two linear axes into a coordinate system where the horizontal axis is a linear axis and the vertical axis is a rotary axis, and the non-circular contour processing program is compiled with this coordinate system. It is usually used for turning straight grooves or grinding cams on grinders.

NURBS Interpolation (M)

Most industrial molds for automobiles and airplanes are designed with CAD. In order to ensure accuracy, non-uniform rational B-spline function (NURBS) is used in the design to describe the surface and curve of sculpture (Sculpture). Metal processing WeChat, the content is good, worthy of attention. Therefore, the CNC system has designed the corresponding interpolation function, so that the expression of the NURBS curve can be directly commanded to the CNC, avoiding the use of tiny straight line approximation methods to process complex contour surfaces or curves.

Automatic tool length measurement (Automatic tool length measurement)

Install the contact sensor on the machine tool, and program the tool length measurement program (using G36, G37) like the machining program, and specify the offset number used by the tool in the program. Execute the program in automatic mode to make the tool contact with the sensor to measure the length difference between the tool and the reference tool, and automatically fill this value into the offset number specified by the program.

Cs Contour control (Cs Contour control)

Cs contour control is to change the spindle control of the lathe into position control to realize the positioning of the spindle according to the rotation angle, and it can be interpolated with other feed axes to process workpieces with complex shapes.

Manual absolute ON/OFF

It is used to determine whether the coordinate value of manual movement after feed pause is added to the current position value of automatic operation during automatic operation.

Manual handle interruption

Shaking the handwheel during automatic operation can increase the moving distance of the motion axis. It is used to modify the stroke or size.

Axis control by PMC

The feed servo axis controlled by PMC (Programmable Machine Controller). The control instructions are programmed in the PMC program (ladder diagram). Due to the inconvenience of modification, this method is usually only used for the control of the feed axis with a fixed amount of movement.

Cf Axis Control (T series)

In the lathe system, the rotation position (rotation angle) of the main shaft is controlled by the feed servo motor like other feed axes.　　 This axis is linked with other feed axes for interpolation, processing arbitrary curves. (Common in older lathe systems)

Location tracking (Follow-up)

When the servo is turned off, emergency stop or servo alarm, if the worktable moves mechanically, there will be a position error in the position error register of the CNC. The position tracking function is to modify the position of the machine tool monitored by the CNC controller so that the error in the position error register becomes zero. Of course, whether to perform position tracking should be determined according to actual control needs.

Simple synchronous control

One of the two feed axes is the master axis and the other is the slave axis. The master axis receives CNC motion commands, and the slave axis follows the movement of the master axis, thus realizing the synchronous movement of the two axes. The CNC monitors the moving positions of the two axes at any time, but does not compensate for the errors between the two. If the moving positions of the two axes exceed the parameter settings, the CNC will issue an alarm and stop the movement of each axis. This function is often used for dual-axis drive of large tables.

Three-dimension tool compensation (M)

In multi-coordinate machining, tool offset compensation can be performed in three coordinate directions during tool movement. It can realize the compensation of side machining with the tool and the compensation of the end machining with the tool.

Tool nose radius compensation (T)

The tool tip of the turning tool has an arc. For precise turning, the radius of the tool tip arc is compensated according to the cutting direction during machining and the relative orientation between the tool and the workpiece.

Tool life management

When using multiple tools, group the tools according to their life, and set the order of using the tools in advance on the CNC tool management table. When the tool used in processing reaches the life value, the next tool in the same group can be replaced automatically or manually. After the tools in the same group are used up, the tools in the next group will be used. Ladder diagrams must be compiled for tool replacement whether it is automatic or manual.