The machine tool coordinate system is the inherent coordinate system of the machine tool. The origin of the machine tool coordinate system is called the mechanical zero point (or machine tool zero point), also known as the reference point. It is the mechanical origin specified by the machine tool manufacturer, and is usually installed on the X axis, Y axis, Z The maximum stroke at the positive direction of the axis, 4TH axis and 5TH axis. When the CNC device is powered on, it does not know the mechanical zero point, and it is usually necessary to automatically or manually return to the mechanical zero point.

There are two types of zero return mode: 1. After the block;

                              2. Before the stop. Set by bit parameter NO: 6#1.

There are two ways to return to zero: 1. One turn signal; 2. No one turn signal. Set by bit parameter NO: 6#6.

When the motor does not have a one-turn signal when returning to zero, the return to zero mode is divided into two types, A type and B type. Set by bit parameter NO: 6#7, the method of setting the system zero point is introduced in detail below:

01 The operation steps of the pulse type servo mechanical zero return

Press the machine zero key to enter the mechanical zero return operation mode, at this time, the words "mechanical zero return" are displayed in the lower right corner of the LCD screen film.

Rotate the X axis, Y axis, Z axis, 4TH axis or 5TH axis to return to the mechanical zero point. The zero return direction is set by the bit parameters NO: 7#0~NO: 7#4.

The machine tool moves in the direction of the mechanical zero point. Before the deceleration point, the machine tool moves quickly (the movement speed is set by the data parameters P100~P104). After touching the deceleration switch, the data parameter P342~P346 is used to set the return speed of each axis to get out of gear. After the block, it moves to the mechanical zero point (that is, the reference point) at the speed of FL (set by data parameter P099). When returning to the mechanical zero point, the coordinate axis stops moving and returns to the zero indicator light.

 

 

 

02Soft limit parameter modification method

Set bit parameter NO: 0#0=1 to configure the GE series multi-turn absolute version, manually move each axis to the position of the zero point of the machine tool, press the system key to enter the system page, and switch to display the [+bus configuration] sub-interface through the corresponding soft key . See Figure 3-3-5-1 for details.

 

 

 

 

03【+Bus configuration】Interface operation instructions

Press the [+Bus Configuration] soft key to enter the bus configuration interface shown in Figure 3-3-5-1. You can view the parameters and modify the related parameters. The specific operation methods and steps are as follows:

Enter <input> operation mode;

Press the up, down, left and right keys to move the cursor to move it to the item to be changed;

Follow the instructions below to make changes;

Whether the bus

0: The transmission mode of the drive unit is pulse

1: The transmission mode of the drive unit is bus

Encoder type

0: incremental 1: absolute

Axis expansion card

0: No expansion card 1: With expansion card

Grating type

0: incremental 1: absolute

Spindle expansion card

0: No expansion card 1: With expansion card

Multi-turn absolute zero setting

First, set the gear ratio, feed axis direction and zero return direction of the system end, power off and then power on again.

In MDI mode, set "Whether Bus" to 1 and "Encoder Type" to 1 on the bus configuration interface, and manually move each axis to set the machine zero position.

Move the cursor to the setting, press the <input> key twice according to the prompt, the zero return indicator lights, the current position of the absolute encoder of the motor of each axis is recorded as the machine zero, the system is powered off and re-powered, and the zero return indicator remains on. The negative boundary and the positive boundary can be manually set according to the maximum stroke of the actual machine tool, so that the absolute coordinate of the current machine tool is shifted forward or backward by a value, and finally the bit parameter NO.61#6 is set to 1, positive and negative limit Only effective.

Whether to configure the grating. Each axis sets whether to configure the grating, 0: no configuration grating, 1: with configuration grating.

Press enter to confirm

Note 1: After the machine zero is set, if the system returns to the zero direction, feed axis movement direction, servo and system gear ratio, the zero point will be lost, and the machine zero must be reset.

Note 2: After resetting the machine zero, it will affect other reference points, such as the second and third reference points to be reset.

 

 

 

 

04 Conclusion

By following the above description, we can understand the problem of setting the mechanical zero point during the debugging process. The absolute encoder sets the zero point, and the zero position can be set according to the absolute position of the motor feedback.