3.12.1.1 Encoder Mode

Use the up and down direction keys to move to the item you want to select and press ENTER to select. The three modes are described as follows:

1.	Under this category, the machine can install increment style square wave encoder.
2.	Every time the machine open, it need to conduct homing to get the correct machine homing position.

Abs/Inc

1.	For this usage, the machine can install increment style square wave encoder.
2.	The machine installer must appropriately use manual mode, move the machine to a particular homing location, then through PLC set this point to machine homing.
3.	For this usage, the machine doesn't need to conduct homing, Because the CNC controller will continue to store the machine position into its memory. If the machine is not moved, prior to shutting down, the next time it open, the CNC controller will through its memory read the machine position. If the machine has been moved, then repeating the second machine homing and set up is required.
4.	Servo must have breaking system. To prevent the servo system slipping, causing error between the actual position and the machine memory's position.
5.	System must make sure proper shut down, so PLC have a chance to initiate break. So, system cannot be allowed abnormal power shortage. For example, you cannot cut the power via EMG, because under the circumstances the machine position will no longer be accurate. If the above took place, re executing secondary machine homing setting procedure, is a must.

Note:

Suggest a break for each motor, to prevent slipping while power shortage or sending power, causing error. (Start brake in PLC Close)

Abs/Abs

1.	For this usage, the machine must install absolute square wave encoder.
2.	The Installer shall, at the appropriate time, manually to select home, then through PLC sets this point as mechanical home or set servo drive parameter as mechanical home. During this time, absolute encoder readings are stored in the servo driver memory.
3.	Whether the machine has been moved after power is off or not, executing homing is not required, because the CNC controller will through PLC read back the encoder of the servo driver and calculate the actual position of the machine.

Condition of the two different types of the absolute encoder is as following:

The external drive is an absolute encoder

The driver will record the position data, the controller needs to fetch each external position data on external servo driver of axis to confirm position correctly.

The procedure of fetch position data from servo driver:

Fetch position procedure must by PLC program when PLC to fetch the position data from servo driver, and procedure as below:

(1)	When close normally (F2→File→System Shutdown) The current mechanical address is stored in the axial driver.
(2)	The next time it is powered on, it will be read back to the position of the driver and reset to the machine position of last time power off.

This way homing can be neglected when turn on the machine, when using this function, parameter set to no need for homing, can correctly use soft limit function.

External non-absolute encoder

CNC controller can record the last position when turns off the machine, no axis can be moved when machine turns off. This way even if the outside is non-absolute encoder, homing is not necessary, but must be aware of the following:

1.	Each axis must have break, to make sure when turn off the position is accurate.
2.	Fine PLC plan, when turn on and turn off, each axis will have minor movement, this cannot be prevented, thus the PLC must do the following:

(1)	Before turn on, only release the break, after making sure CNC controller and driver are running.
(2)	Before turn off, machine can only shut down, after PLC break.

3.	Must execute normal shut down procedure, cannot turn off the CNC controller power directly, this will cause PLC having no chance to break, causing position error.

Note:

Absolute encoder position feedback is an optional function, detail please contact our company's sales people.