Special funkcions

Special functions
(detailed description)

Modify: 02.05.2005

Detailed description of the functions programmed into the controller (Firmware V5.0.X). These can be accessed in two ways:

1. Functions available both in on-line mode (CNC mode) and by using Setup (from the PWM Manager):

- Repeated localization of end position. The direction + end position coordinations belonging to the particular axes( X, Y, Z) are localized again.
How to access: By pressing and holding depressed the delete button during switching on the CNC (Power ON + button).

There is no prefixed coordination of motor rotation direction and the end position switch belonging to that! This can be freely varied within the axis. The coordination is performed by this function, which is stored by the controller.
During activation the controller will rotate at the speed determined in the TF register first the motors of the X axis, then that of the Y axis, and at last that of the Z axis. The value of the speed can be read out from the „Overdrive Indication” field of PWM Manager.
It is important that neither of the end position sensors should be pressed at start, otherwise the controller will pull up and alarm!
In the course of the first switch-on of a freshly ready-made controller this function can also be activated by itself. The first job of the controller is to establish these coordinations. (During putting it ino operation – if the controller is not built together with the mechanical parts yet, the coordination can also be given by hand – by connecting the particular axes V1 or V2, -temporarily). The controller cannot enter into ONLINE (CNC) mode until there are valid coordinations. Later the final coordinations can be recorded together with the mechanical parts again by repeated execution of the function.

- Motor tuning. Stepping motors + mechanical parts determination of the biggest speed without steploss by preprogrammed (Setup) step-path and error tolerance.
Access: with CNC switched-on press and hold depressed end position switches YV1 and YV2 (3D) or ZV1 and ZV2 (2D).

The purpose of tuning is to measure the biggest speed without steploss that can be reached by the assembled unit of all the three axes, motors and other mechanical parts. The measurement is performed with an unaccelerated motor drive (it makes the motor step directly at the given speed) and with full direction change (the worst situation that can be encountered).
It adjusts the threshold value of the overdrive indication according to the results of the tuning (TF registers and OVER DRIVE LED). It has no affect for other parameters (for each axis with its own value, but with a common LED indication). OVERDRIVE indication has a great importance during the set-up of the CNC controlprorammes. It indicates if any of the axes is driven at a speed bigger than the safest value. The limit values belonging to the indication can only be exceeded by continuous acceleration, deceleration and with stepping pulses perfectly equal (Mach2 is the most suitable for this purpose)! Sudden acceleration, deceleration or inequable motor-drive is likely to cause a step-loss.
When holding the end position switches depressed the controller alarms and the diagnostic routines will start only after releasing both end position switches (because of safety reasons).
In the course of programming-up the diagnostic routines take the initial values of the speed from the base values or from the TF values given for each axis in the Setup (in the PWM Manager), and it searches for the limit values by decreasing these. The initial speed value can be read out in the „Overdrive Indication” field of the PWM Manager

- Step number of tuning-path of the motor (see PWM Manager). The motion in mm unit can be easily calculated from the specifications of the motor. For example let the drive be a threaded shank size of M8, how many pulses are necessary for 1 mm? (M8: 1 turn =1.25mm)! The longer the motion used for measuring TF, the more accurate its value will be, but the longer is measurement as well. It should be taken into account that all the three axes vill be measured by using this motion. Care should be taken for example that the possible value of the motion for the axis Z should not be lower than the value used for the measurement, otherwise the diagnostic routine will stop and produce an error message (the tool will clash to the end position on the reverse side)!

- Error tolerance of end position tuning-path of motortuning (see PWM Manager) in Step/measurement.
For the measurement the controller will also use the data of one of the end positions of each of the three axes. Because of other mechanical reasons (for example backlash) the end position switches will not switch exactly at the same position after having been pressed for several time as in the position they switched at first. Here a tolerance value can be given, during which the controller will not take the measured steps as setp-loss during the diagnostic process. By this the end position errors can be compensated. The lower values are choosen, the stricter the measurement will be. For example with a sensor of HALL type the programme can perfectly do even with a compensation of 1 steploss (in case of mechanical push buttons a bigger value must be applied)!

In the first part of the measurement the controller looks if any of the end position switches is depressed. If so, it lights one of the LEDS (OVER DRIVE), stops and alarms. Because of determination of the direction neither of the end position switches may be depressed at the beginning.
In the second part it checks for the value of compensation. At the lowest revolution and the biggest torque (TF+T1 the motors must be capable by all means to perform the steps without any error), makes the motors step the programmed motion forward and then back. Then it checks if the measured error is within the given tolerance. If not, it lights both LEDs and stops with alarming. In this case the value of the tolerance must be increased with a bit (for example with 1) and the test must be performed again. If the measured value is correct the controller will begin to measure the motors of the X, Y, Z axis (one after the other) with gradual acceleration (with the given value of motion). At the speed it finds steploss (out of the value of error tolerance) it will shift back the value of TF and stores it. If the measurement is performed for all the three axes, it will perform a reset and after restarting the CNC will go to the stand-by state (it is ready to work).
If it cannot find a good value for the speed because the measurement is good even in case of the lowest value of TF (which is 0), it will light the red LED and stops with alarming. It can be because an unreal high value was given for the tolerance at the beginning (for example 255 Step/measurement).

- Holding-path PWM tuning. Adjusting the force necessary to keep the motors in home position by controlling the manual moving force at constant PWM frequency determined during setup. Access: With CNC turned-on, press both end-position switches of the Y axis (YV1 + YV2, in case of 3D type of controller, ZV1 + ZV2 in case of 2D type of controller).

Manual PWM tuning (PWM is partly active).
By this function the best ration of T2 + T3 at the same frequency separately for each of the 3 motors can be searched and adjusted. It is important that both end position switches of Y axis should be available for the manual operation (the carriage of Y axis must be somewhere near the middle position)! After starting the tuning a sound signal can be heard, after which both of the end positio switches must be released.
Entering the tuning menu, PWM control of all the motors will be turned off (there will not be any excitation for them) and the LEDs will go lighting (LED1 and LED2). In this state it can be examined (for a reference for later comparison) how great the opposition of the motors without excitation is against manual motion. By pressing the button, the holding path (T2 + T3) PWM control of the X axis will be switched on (according to the Setup). In the course of adjustments you should check the actually adjusted PWM brake-force always by manual driving (by rotation). The brake-force of the PWM can be increased or decreased by the two end position switches of Y axis. The frequency of the PWM comes from the sum of T2 and T3 (given during Setup), and this by taking this sum (frequency) as constant the duty cycle can be stepwise increased or decreased in steps of 0.1 ms (by the mean of the two end position switches). During the adjustments the sum of T2 and T3 will always be constant (the same frequency). If the limit value (0 or 255) of any of the timings (T2 or T3) will be reached, a sound signal will let you know that the value of PWM cannot be changeed in this direction any longer. If you want to change the frequency too, you should give in another sum of T2+T3 during Setup (in the PWM Manager).
If you managed to find the required brake-force, By pressing the button store it to the particular axis. The PWM will be switched off and the LEDs will go on again. By pressing the button again the PWM of Y axis will be switched on. The storage of the adjustment is performed in the same way as that of the X axis, and so on for the Z axis. At the end of the function the controller will reset itself and will restart with the new values in ONLINE mode
It is worth adjusting the lowest possible brake-force, which is sufficient to hold the motors in a stable position, because the motors will have more time to rest (they will cool faster).

- Direct data-loading through the LPT port and extended diagnostic routines. During Power On both end position switches of the X axis must be kept depressed (XV1 and XV2) in case of 3D and 2D controller.

The controller enters into PC-Link mode, which makes possible the direct data-communication between the controller and the PWM Manager. In this state it is possible to upload data (Setup) from the PC to the registers of the controller and other test functions become available as well.

2. Function that can only be accessed via Setup (from the PWM Manager, through the PC-Link):

- Identificaion of phases of the motors, with the help of end position, LEDs and push-button tests.

During the test the PWM is active.
It makes all the three motors step in every second forward for the PIC. The correct phase sequence of each motor can be checked. None of the motors can step backwards (to the reverse direction) not even for a second. If one or more steps have been done backwards, or the motor steps criss-cross, the correct sequence belonging to the unidirectional rotation can be established by exchanging the phase lines of the motor. The particular direction of the rotation has no special interest, the important thing is that the motor should rotate into the same direction for each step!
By using the end position buttons, the motor of the axis belonging to the depressed button will stop and a sound signal can also be heard (two short ones for V1 and V2 with different pitch), releasing the button the motor will step on again. Doing so, the functionability of the end position buttons can be checked and whether they are exchaged among the aqes. If pressing a button the motor that stopped is not the one which belongs to that, the at least two of the buttons are exchanged (it is important that the end positions of an axis should control their own motor)!
The functionability of the push button can be checked by the short sound with a different pitch when pressing it.
During thentest the two error indicating LEDs (LED1, LED2) should blink in turn with a fequency of 1 Hz (test of LEDs).

- Diagnostics of the counters.

During the test the PWM is active .
During stepping the counters (for example: by using Mach2), short sound signals with different (X, Y, Z) pitches must be heard. For the X axis one of the LEDs, for the Y axis the other should go on. For the Z axis there is no LED, (only a sound signal). The LEDs can be cleared by the push buttons. The functionability and the interference sensivity of the counters can be tested by them.
What should be noticed:
- whether each of the three counters steps separately using software (PC) control (cabel-, and connection test);
- in stading positionálló (using PWM) the counters should not step (interference filtering);
- when controlling a counter, the other counters should not step (interference filtering).

- Online Switching on the forced impulse-loss monitoring (modified Online mode.*

Switching it on, it detects in Online mode all the pulse interferences, even those of handled (in normal mode only the interferences are detected that cannot be corrected).

- Load test of the power supply of the motor from 0 up to 200%.

See the detailed description of PWM Manager.

- Direct identification of the phases of the motor.

See the detailed description of PWM Manager.

From the functions activated during Setup one can quit by the delete button kept depressed during switching on the CNC (Power ON + push button).