Profi2M_Expert CNC Controller
(Micro-Step CNC Axis Driver)

Modified: 2009. szeptember 01. kedd

Discontinued!

Content:
Introduction
Installation

Profi2ME is a version of Profi2M with increased knowlidge. Profi2ME is a high-power,  micro-stepping, stepping motor, CNC control electronic unit, with dynamic configuration abilities. The controller, which is an axis-conmtroller belonging to the Profi2 CNC Controller family, because of its arrange-able build-up can be built as 1 to up to 4-card unit for a base card (Profi2B), according to the needs. By using suitable CNC controlling software, (e.g. Mach3) the number of base cards can be raised up to 2 and in this way CNC machones with up to 6 axes can be built.
By some developments and services Profi2ME can further increase the available rev. number of the motors and it is able to keep them in the holding path more efficiently in standing position.

Picture gallery:
(click to zoom)

Main features (DSP V1.1):

- Step/Dir sytem, stepping motor CNC Controller,
- One-axis, modular, arrange-able build-up for each card,
- 1 ; 1/2 ; 1/4 ; 1/16 adjustable micro-steps,
- 2-phase, bipolar power transmission bridge (with uniform FETs),
- 3.3A - 9A, regulated, motor phase-current drive,
- Speed-increasing, mixed mode current decay controlled by DSP,
- Programmable holding path current regulation,
- Reduction of active heat production and noise,
- 50V maximum motor power supply voltage,
- Tuning factor up to maximum 25-fold,
- 300 000 Step/sec signmal processing speed,
- Protection against thermal overload,
- Constant torque (motor-power) regulation (PWM),
- Reduction of modulated PWM noise with increased efficiency,
- Sinusoid type current regulation curve (reduction of motor resonances),
- Easy Setup (fast putting into operation, by means of Jumpers),
- High-level noise protection (for industrial applications),
- Installed massive cooling,
- Two-sided partly SMD-mounted PCB,
- Compatibility with Profi2B,
- etc.

General description:


(Profi2ME PCB)

Profi2ME is an arrange-able build-up, one-axis professional controller. The default build-up means that one Profi2ME controller belongs to each motor.

Between the Profi2ME Controller and the PC a Profi2B base card can be found. The task of the base card is to fit the printer (LPT) port of the PC (amplification and distribution of the signal). On the Profi2B base card basic I/O ports (5 inputs and 4 relay outputs) and the digital power supply of the whole system (+5V és +15V) can be found.


(Profi2B Base card)

According to this, maximum 4 Profi2ME Controller can be connected to a Profi2B base card. The system, - built-up in this way, - uses one PC-LPT port and can be a 4D (four-axis) CNC machnine, which has 5 additional inputs (these can be used e. g. for end positions, digitalizes peaks, recording reference points, etc.), and 4 relay outputs (good for e.g controlling of Charge-Pump protection, finishing motors, cooling, lubrication, etc.). If even more axes or I/O ports are needed, then the system can be extended by adding more LPT ports and Profi2B cards to the the PC , (only the cabability of the CNC controlling programme limits the possibilities).
The Profi2B base card was designed to work with maximum 4 Profi2ME Controllers.


Building up a 4D-system

Profi2ME Controller works with standard, positive logic, TTL-level Step/Dir signals, so moving controllers made by other manufacturers (e.g Maxstepper, USB-Step/Dir generator, RS232, etc.) can also be used.

The type of the recommended 2-phase stepping motors:


(Stepping motor)

- Bipolar motors,
- Unipolar motors (with bipolar connection),
- 8-wire, univeral motors (with bipolar, paralell connection).

Between 2 bipolar-unipolar motors with the same electric parameters a torque difference of up to about 40% can be measured, in favour of the bipolar one. The use of bipolar motors is recommended.
The tuning factor* of Pofi2ME Controller is 10 - 25 fold, depending on the inductivity of the motor applied. The controller requires a minimum tuning voltage of 6-fold.
The lower is the inductivity of a motor, the higher is the applicable tuning factor. The following table helps with determining the maximum suggested motor power supply voltage:

Base voltage of the motor:
(voltage indicated on the motor)
Recommended motor power supply voltage:
(maximum tuning voltage)
1V 20V
2V 40V
3V 45V
4V 45V
5V 45V
6V 45V
8V 45V
9V 45V
10V 45V
11V 50V
12V 50V
stb. ...

Attention! 50V must not be exceeded. Take care of the possible voltage overrun of the unloaded power supplies.

 The maximum allowed motor power supply voltage that can be connected to the controller is 50V. The continual load that can be handled by the power transmission FET bridge is 9A/phase. At the maximum load intensive ventillation (provided by fans) must be provided.
The variable duty cycle PWM signal generated by the controller has a frequency value of 20kHz, so it generates in the motors a voice that cannot be heard by human ears (mild, swishing sound can only be heard). The assistant processor configurates DSP on the fly, further increasing the dynamic of the motor, and reducing the noise and the heat production.

Signals:

 Status  LED:

- Continually lighting: Stepping phase.
In this state the Controller excites the motor with a current determined by the Current Jumper line. This is the moving phase. Here the controller works optimalised to the speed of the processor.

- Blinking: Holding path phase.
The Controller excites the motor with a holding-path current determined by the Hold Jumper. This is the position-holding phase of the motor. Here the processor of the Controller is optimalised to this holding path state (optimalised to cooling).

 Overload  LED: Indication of overload. The controller measures continually the temperature of the heat-sink of the power trmasmission bridge and above 70°C the operation of the Controller will be prohibited.

Further developments:

- Profi2ME Controller realizes a special current regulation with the help of the DSP processzor (a regulation, which varies depending on the function of phase position, time, moving state, dynamics).
The sinusoid-type driving methode realises smooth stepping in the micro stepping system, therefore the motor resonances decrease in a high extent. By its use the acceleration of the motor can be increased about 30%. Because of the mixed mode current-decay regulation the quality of running is extremely good (further improving the efficiency of resosnace-reduction).

- The DSP assistant processor continually examines the Step signals, and will change the adjustments and reference voltages of the main processor depending on the values of the signals. By its use the motor drive can be optimalised to vaiable moving states. In holding position it will automatically reduce the motor excitation after a so-called dynamic dumping time, (holding path state), supporting by that the cooling of the unit.

- The Controller has an Easy Setup. this means that before putting the device into operation only the Jumpers need to be adjusted and the work can be started. By the means of Jumpers the nominal current of the motor and the holding path current must be adjusted. The electronics of the device does not need exact adjustments (it is linear and tolerant), so the check of the adjustment by a measuring instrument is not necessary.

- The controller has been optimalised to Mach2 & Mach3 CNC controlling softwares. The procerssor (DSP) makes possible to choose extremely short Dir preset.

- Because of the industrial, professional type of the Controller, it has a strong noise protection, which can be raised to the maximum level by the means of correct installation (mounting). The case-mounted version has all these features.

*Tuning factor: it determines the maximum applicable motor power supply voltage for a given motor as the function of the base-voltage of the motor (Upower supply=Umotor× Tuning factor).


Installation, putting into opeation
(detailed description)

Mechanical build-up, housing (accomodation):

PCB:

- Two-sided, partly SMD-mounted PCB,
- Size of the PCB: 169× 90 mm, minimum heigth is 50mm (with ventillation),
- 4 holes with a diameter of 3.5mm for fixing screws, with an allocation of 159×179.mm.

The Controller can be mounted by setting on the edge, and one can be mounted to the top of the other, so that the possible smallest place could be demanded. Care must be taken of the free ventillation. The optimal buil-up of the controller is a block, where the cards are mounted set on their shorter edge, one is mounted to the top of the other with metal spacers.


(recommended block-type build-up and ventillation)


(Compact build-up of Profi2)

It must be placed far from (electric) noise sources. By placing it into a case, it will be protected from mechanical effects, dust, but the free ventillation must be ensured. Do not expose it to shock.

In case of motors with nominal current consumption more than 4A/phase forced cooling (by fans) is necessary (by the means of fans).

Electric connections, wiring:

All the wires should be shield-mounted
The high-current wires (connection of motor and its power supply) are on a screwed terminal. The cross-section of the wires is maximum 1.5mm2. All the high-current wires should be shielded twisted pairs. For this purpose the so-called industrial 4 - 20 mA signal cable, which is a 4-wire (2 twisted pairs) shielded with a cross section of 0.5 mm2, is very well suited (available in special electric shops).


(2×2 twisted pairs, with a cross section of 0.5mm2)


(one twisted pair are the 2 ends of 1 motor-coil, and the shields go to the common GND rail)

According to the shop the cable type is GJY STY and it is available with several cross-sections (0.5mm2 is the suitable).

Care must be taken of the right polarity of the motor connection (motor power supply). In case of wrong connection the Controller immediately goes wrong!
The high-current wires should be mounted as far as possible from the Controller.

The connections of the digital power supply (Power) and the signals are lines of pins. The pin-line connections are using standard internal PC (CD-ROM - motherboard), audio (shielded) cables. The usage of such (shielded) cables, with wide black connector at both ends is strongly recommended. The connectors are positioned, reverse connection is not possible.


(Connections, Jumpers)


(shielded signal cable)

>Care must be taken not to exchange the signal and power lines. Wrong connection may cause the Controller to go wrong immediately!

The shield must not be used as active wire (no current must flow through them). All the shielding must be connected to the digital minus pole (GND or M-), (on the terminals of the Signal and the Power connection these happen automatically). Take care of avoiding the formation of ground loops. The high-current wires must be mounted as far as possible from the signal wires.

The wires should not touch (should not be in connection) with the heat sink (danger of melting)!

To a Profi2B (base card) maximum 4 Profi2ME motor controller cards can be connected.
A Profi2B card provides the digital power supply voltage for the Profi2M Controllers (+5V and +15V), as well as the amplified Step/Dir signals. Besides that it has 5 inputs and 4 relay outputs (they can be used freely).
The I/O wiring must be shield-mounted. The high-current wires (motor power supply wires) should be twisted pairs. For the small-signal wires (Signal, Power) the internal PC audio cable (which is shielded) is recommended (this was designed to be used).


(Profi2B Base Card)

A letter, A - D must be attached to the each of the 4 Profi2M Controllers, and the letter attached to the controller should be written onto it by an alcoholic marker. Later, based upon this marking the bit allocation table - controller assignation can be performed.
The signal connector of Profi2ME must be connected to the signal connector of Profi2B (upon the denomination)!
The power connector of Profi2ME must be connected to the power connector of Profi2B. Regarding the power supply connections, the marking has no special importance (they are the same).

Regarding the power supply system, it is possible to apply a common motor power supply (all the motors have the same power supply), or a distributed (even separate power supply for each axis) power supply system can be designed (in the later case only the minus terminals of the motors must be common).
The digital GND (Profi2B) and the minus terminals of the motor power supply must not be combined outside the Controller (they are combined inside the Profi2ME Controller).

Before selecting the motor power supply voltage it is recommended to read the Tuning description of Profi2ME, which helps to choose the right parameters.

The power supply voltage of the motor does not need to be stabilised, but filtering with a capacitor of min. 1000uF/A is necessary (oversizing the capacitor is not at all harmful, even it is useful...)! As loading current the phase current of the motor should be taken into account (in case of a common power supply the summerised value for each axis should be taken into account).
At least a tuning voltage of 6-fold is suggested.
Maximum 50V voltage can be switched onto the controller. This value must not be exceeded! Take care of the increased voltage of the unloaded motor.

Connection of the Motors:


(connections of the phases of the motor and the power supply of the motor)

- The Controller was designed to be used with 2-phase, bipolar (4-wire) motors.
In case of bipolar motors the common phase ends must be connected to SK3 (L1) and SK2-ba (L2). The power supply voltage of the motor must be connected to SK1 (with the right polarity). The phase order does not matter, in the CNC softwares the rotation direction can be changed.


(Connection of bipolar motors)

- In case of universal (8-wire) motors, it is worth connecting the coils paralell in pairs (paralell connection of the coils belonging to the same phase). In this way higher torque and better tuning-ability can be achieved.


(Connection of 8-wire motors)

In this case the motor current to be adjusted is the double of the coil-current (or that of the value indicated in the specifications).

- Connection of unipolar motors is also possible. This can be done in two ways:

A B

(How to connect unipolar motors)

There are important differences between the 2 connection modes.

Mode A: about 20 % higher torque can be achieved at low speed (twice as many windings are excited), but the available maximum speed is a lot smaller (because of the a 2-fold inductivity) at the same power supply voltage. The base voltage and the inductivity of the motor is twice as much as those given in the specifications. The current to be adjusted is the nominal current of the coil.

Mode B: All parameters are the same as given in the specifications (higher speed, nominal torque). The current to be adjusted is the same that is indicated on the motor (or given in the specifications). It does not matter that within the coil which end is connected to the middle wire of the Controller (it influences only the rotation direction) This is the preferred mode of connection.

- Serial connection and synchronous drive of two motors for an axis can also be realised:


(2 pieces of 8-wire motors on the same axis)

Only absolutely identical motors are allowed to be serial connected. In this case the resultant motor is a motor with twice as much operation voltage (and inductivity). Its tuning-ability is poorer than when only one motor is connected.

In case of the application of Mach3 softwares, the logical assingnment of the axes (slave modes) can be solved and the full synchronous driving can be realised, so on the controllers a so-called 2-motor drive mode for each axis with one motor can be realised.


(logical axis assignments)

More information on motor tuning and designing the correct motor power supply can be found in Tuning description.

The power supply of the motors must be protected by suitable fuses (serial connected with M+).
The digital power supply (on the Profi2B card) is short-circuit-protected.

Adjustment of the motor current (Current trimer):

Before switching voltage onto the Controller for the first time, the following steps should be done:

- It should be checked whether the connections are right (according to their location and polarities) and whether the motor circuit is shortcircuit-free (the Controller is not shortcircuit-protected).
- The stepping current and the holding path current must be adjusted.
The controller contains a line of jumpers. The jumper line for the stepping current is the Current Jumper field (its common with the line of ICP). The closest current value to the nominal current of the motor must be adjusted in this line.
The part Hold controls the holding path excitation in 2 grades. It is worth choosing the smaller grade so that the best possible motor cooling could be achieved. Should this value be unable to hold the motor in a fixed position, then the higher grade must be choosen.
The pin number 1 of the jumper line is marked.


(Current jumpers)

Stepping excitation (nominal current of the motor):

Current field:
[Position of closed jumpers]

Excitation current:
[Peak]
--- excitation for testing: 4.1A
1-2 3.3A
3-4 3.7A
1-2; 3-4 4.1A
5-6 4.5A
1-2; 5-6 4.92A
3-4; 5-6 5.33A
1-2; 3-4; 5-6 5.74A
7-8 6.15A
1-2; 7-8 6.55A
3-4; 7-8 6.96A
1-2; 3-4; 7-8 7.37A
5-6; 7-8 7.77A
1-2; 5-6; 7-8 8.18A
3-4; 5-6; 7-8 8.59A
1-2; 3-4; 5-6; 7-8 9.00A

(Table of stepping excitation)

Peak Current setup= Motor RMS × 1.4 !!!

The controller is not sensitive to the exact adjustment. It can be modified at any time during operation (observing the voice and upwarming of the motor).

Holding path excitation (excitation for holding in position):

Hold field:
[Position of the closed jumpers]

Excitation current:
[holding path current of the motor]
--- 3.3A
9-10 4.1A

(Table of holding path excitation)


(Current jumpers)

- Adjustment of the stepping system (resolution):
The resolution of the motor stepping can be adjusted on the Micro-Step Jumper-line.


(Jumpers, markings)

Jumper positions: Stepping system: Stepping revolution:*
1-2; 3-4 one whole 200
1-2 quarter 800
3-4 half 400
- one sixteenth 3200

(Micro-Step Table of DSP Config Jumper-line.)
*Referring to a motor of 1.8°.

By doing the above-written instructions the Profi2ME Controller is ready to work with a CNC machine.

The configuration adjustments of the controllers on the PC-side can always be found in the documentation of the applied base card (if the Profi2B interface card is used, then its description can be found on this web-page). To make the set-up easy fast setup files can also be downloaded.


(appearance of a new profile in Mach3-ban after setting-up a fast setup file)

The Controller needs NON-inverting Step signals (its makes stepping on the rising edge).


(Motor tuning screen of Mach3)

Recommended minimum pulse data: Step Pulse=2, Dir Pulse=2!

Usage:

During normal operation of the Controller (in Online mode) the  Status  LED indicates normal operating condition. Its continual lighting indicates stepping condition, its blinking signals the holding path state.
The  Overdrive  LED indicates overheating of the Controller (appr. above 70°C) and it will prohibit further operation of the controller until it cools down.
This refers to some overload or insufficient vetillation.

The excitation of the motors can also be adjusted during operation. By observing the voice of the motors (at relatively low revolutions, e.g. 500 - 1000 steps/sec) the excitation force can be adjusted (the motor will be the smoothest/the most silent, when it operates with the most suitable values).

The spplied values of the motors, the direction of rotation and the acceleration values (and several other parameters) must be adjusted within the applied CNC control programme (see e.g. Mach3 descriptions).

Further additional information can be found in the dexcription of Profi2ME motor-tuning too.