7.1.2 Dual Feeds for Axis (Only A-axis Can Set as Dual Axis)
Some machine needs two set of servo motor to drive an axis, for example gantry bridge CNC machine, INCON-M84/M86/M86R CNC controller provides advance dual feeds drive function. Dual feeds drive use A axis (fourth axis) to work in partnership with X/Y/Z axis, to achieve dual feeds drive function.
Note: Only A axis (fourth axis) can be set for X/Y/Z functioning together.
Within PLC, use plc.vto3.bit.ddmt0 and plc.vto3.bit.ddtm1 signal to set such motion.
Signal |
No |
A-axis and X-axis move together |
A-axis and Y-axis move together |
A-axis and Z-axis move together |
plc.vto3.bit.ddmt1 |
0 |
0 |
1 |
1 |
plc.vto3.bit.ddmt0 |
0 |
1 |
0 |
1 |
If A axis and Y axis move as dual feeds drive, machine manufacture needs to use two of the same brand, model and function servo, the A axis parameter of the CNC controller must also be same as Y axis and within PLC, put A axis definition and Y axis as dual feeds drive, PLC example is as below:
#include "plc.h"
#define iDualDriveSafeUmount (plc.gdi[1].bit.bit01)
#define pDualDriveMount (plcData[50])
...
void plcRun(Status &sts, PlcBlock &plc){
...
if( pDualDriveMount == 0 ){
plc.vto3.bit.ddmt0 = 0;
plc.vto3.bit.ddmt1 = 0;// no mount
}else if( sts.state0.bManual &&
sts.state0.bManualMode == 0 && // manual INC
iDualDriveSafeUmount ){
plc.vto3.bit.ddmt0 = 0;
plc.vto3.bit.ddmt1 = 0;// no mount
}else{
plc.vto3.bit.ddmt0 = 0;
plc.vto3.bit.ddmt1 = 1;// A mount to Y, A Y sync
}...
}
CNC controller provides a phase align homing method, let Y and A axis's motor turning phase angle to remain the same, the parameter setting is as following:
- "Machine Parameter → A Axis → Forward Index": Choose this item for whether to phase align homing method.
- "Machine Parameter → Y Axis → Index Offset": With Y axis, return home offset process setting are the same.
- "Machine Parameter → A Axis → Index Offset": CNC controller set Y axis and A axis phase angel relative position.
Detail is as following:
1. |
In the same time close the function, shift to manual mode; enter manuel mode's single movement, when an external safety button is pressed, Y and A axis dual feeds drive function will separate, during this time machine manufacturer can use 0.001um meter to manually adjust the Y and A axis' motor phase angle, align two screws became in united and can dual fees drive, and keep vertical accuracy with X axis. |
2. |
Turn on follow function. |
3. |
Y axis return to home, might take some time, because Y axis and A axis' searching action. |
4. |
After homing press ALT+F8, then press ALT+F3 to enter second page of machine status page, take Yi, Ai search absolute position value - 500, separately set to Y axis and A axis would do. |
5. |
If Yi or Ai search position value is smaller then 500, change setting or (Ai + feed pitch -500). |
6. |
After the setting, twin axis adjustment is complete. |
After setting is done, CNC controller will upon homing procedure conduct the necessary compensation, to let Y axis and A axis' corresponding angel remain the same. Also, when machine first open, homing will take longer, to find the right position.