ATOMI user guidebook

This page collects most ATOMI articles as a single page.

Intruduction to ATOMI

Atomi is an multiaxis motor drive under development.

About ATOMI

ATOMI is a multiaxis servo and stepper motor driver board with up to four axis capability. Based on IONI technology, ATOMI delivers state of the art motion control what comes to quality, reliability, and features.

Benefits

• Closed loop systems to avoid missed steps and lost position
• Ultimate price/quality ratio
• Very small form factor to enable small enclosures
• Single PSU operation, no separate logic and motor voltages. ATOMI operates from 12 to 49 V.
• Direct USB connectivity and full control over SimpleMotionV2 field bus including
  • PWM to analog (0 to 5 V) output circuitry, and
  • external 24 V 500 mA open-drain output buffer.
• Parallel port compatible pin header
• Extra I/O from second pinheader to maximize flexibility

ATOMI user guide

Please read the ATOMI user guidebook for detailed information and specifications.

Feature comparison

Feature	ATOMI DeepStep™	ATOMI Standard	ATOMI Advanced
Motor support
Stepper motor, open loop	Yes	Yes	Yes
Stepper motor, sensorless closed loop	Yes	Yes	Yes
Stepper motor, sensored closed loop	-	Yes	Yes
AC/DC servo motor	-	Yes	Yes
Feedback support
Quadrature encoder	-	Yes	Yes
Setpoint support
SimpleMotionV2	Yes	Yes	Yes
Step/dir	Yes	Yes	Yes
PWM, with or without direction bit	-	-	Yes
Analog	-	-	Yes 1
Operation mode support
Position mode	Yes	Yes	Yes
Velocity mode	-	-	Yes
Torque mode	-	-	Yes
Other features
Acceleration and velocity feedforward	-	-	Yes
Auto setup	Yes	Yes	Yes
Homing	-	-	Yes
VFD out	Yes	Yes	Yes

¹) ±10 V analog setpoint requires external circuitry. The voltage range of ATOMI analog inputs is 0 - 3.3 V.

Specifications

Device variations

ATOMI is available in three different models. See also ATOMI device model comparison.

ATOMI DeepStep™

Basic model for stepper motor operation only

ATOMI Standard

Additional features and supported motor types

ATOMI Advanced

Most features

Main functionality

Function	Description
Servo/stepping motor drive	Closed loop control of various types of servo motors by sinusoidal field oriented control with dead-time distortion correction and high dynamic range torque control. Synchronous AC & BLDC motors Sinusoidal and trapezoidal commutated SPM (Surface Permanent Magnet) and IPM (Internal Permanent Magnet) types Brush DC motors Linear motors Iron core Ironless (with external inductive filter) Stepping motor, 2 phase (4,6 or 8 wires)
Control modes	Torque control Velocity/speed control Position control
Setpoint types	See setpoint signal / reference inputs list Direct set-point tracking via pulse and direction, PWM, Analog, and SimpleMotion V2 Buffered synchronous motion commands via SimpleMotion V2
Closed loop	Cascaded control loops (PIV): Torque / current control, update frequency 20.0 kHz Velocity control, update frequency 2.5 kHz Position control, update frequency 2.5 kHz
Feed-forwards	Feed-forwards working in velocity & position control modes: Acceleration (inertia canceling) feed-forward Velocity (friction canceling) feed-forward
Homing	Integrated homing function for position control mode: Sensorless hard-stop homing Home switch search Index pulse search Soft position limits (eliminate limit switches)
Feedback devices	Quadrature (incremental) encoders
Safety	Safe torque off with 3-way redundancy Charge pump enable input Stopping motor on errors Tracking error (velocity & position) Over speed error Limit switch DC motor runaway prevention on feedback loss Communication error detection
Protections	Over current Short circuit (phase-to-phase) I2t motor thermal protection Over & under voltage Over temperature
Power supply	Externally supplied 12 – 49 VDC Single power supply operation mode, no separate power supply needed for logic
Motor output current 1	AC/BLDC/Stepping/Linear motors (current specified as peak of sine): 0 - 8 A Brush DC motors: 0 - 10 A
Commissioning	Granity setup software
Compliance	CE (LVD & EMC): EN 61800-5-1:2007, IEC 61000-6-1:2005 and IEC 61000-6-3:2006. Notes: The device is Low Voltage Directive (LVD) compliant up to 42 VDC power supply, and above that level the supply voltage is considered hazardous, so external measures (such as or isolation or protective impedance) are necessary to prevent human contact to any circuit connected to the device. In order to meet EMC standard requirements, a proper installation and wiring is necessary. Refer to user guide for proper installation.
Reliability	MTBF: 660000 hours

¹) Currents achievable continuously only with with sufficient coolant air flow. Without forced cooling, typically 30-45% of the maximum range can be driven continuously. Despite of this, maximum current is available for short periods of time even without cooling. Current is automatically throttled on temperature rise to protect the drive.

Motor output

Maximum output current throttling vs device temperature. Current is automatically reduced by device to protect from overheating.

Property	Value	Units	Remarks
Supported motors	Refer to ATOMI device model comparison page		Permanent magnet motors only
Continuous output current	0-8 1	A (peak value of sine)	User settable limit
Maximum effective motor phase output voltage	3-phase AC motors: Vsupply*0.671 V RMS (phase-to-phase) DC motors: Vsupply*0.95 VDC		I.e. at 48V supply, the maximum three-phase motor output voltage is 32.2 V RMS phase-to-phase I.e. at 48V supply, the maximum DC motor output voltage is 45.6 V
Switching frequency	20.0	kHz
Maximum modulation depth	95	%	Maximum effective output is 95% of HV DC bus voltage.
Torque control bandwidth (typ.)	1-3.3	kHz	Motor coil dependent
Torque control cycle time	50.0	µs
Position & velocity control cycle time	400	µs
Power conversion efficiency	93-97	%	Under typical conditions
Motor inductance range @ 48 VDC	0.2-25	mH
Motor inductance range @ 24 VDC	0.1-25	mH
Motor power range	0.01 - 0.5	kW
AC commutation frequency	0-400	Hz	Not capped, may achieve up to 2 kHz

¹) Maximum current is obtainable only for short periods without active air cooling. Drive automatically throttles current limit if drive temperature rises beyond 75 Celsius. Output current capacity reduces linearly between 75 and 90 degrees Celsius from the maximum to zero.

Regenerative resistor

ATOMI has an on-board 15 Ohm 11 Watt regenerative resistor.

Feedback devices

ATOMI supports quadradure (incremental) encoders with single-ended 3-5.5V (CMOS, TTL, open collector).

Quadrature encoder electrical properties

Property	Value	Units	Remarks
Encoder count rate	ATOMI DeepStep™ and Standard: 0-4 ATOMI Advanced: 0-18	MHz	After 4x decoding, digitally filtered
Supply voltage	4.8-5.2	V	Supplied externally (can share same voltage with drive logic supply)
Encoder resolution	ATOMI DeepStep™ and Standard: 100-65535 ATOMI Advanced: 100-15000000	Pulses per revolution (P/R)

Setpoint signal / reference inputs

Setpoint signal type	Status	Electrical interface
Analog	ATOMI Advanced only	0 - 3.3 V input signal. External circuitry needed for ±10 V operation.
Pulse and direction	Standard feature	Maximum step rate ATOMI DeepStep™ and Standard: 4 MHz ATOMI Advanced: 8 MHz
PWM	ATOMI Advanced only	1 - 30 kHz PWM carrier frequency (fPWM), ~3 kHz for optimal operation. Single signal (no polarity input), zero setpoint at 50% duty PWM signal is sampled at 60MHz timer thus reading resolution is 60MHz/fPWM PWM + Direction input mode
Serial communication	Standard feature	SimpleMotion V2 real-time serial bus with open source SDK. Connect through USB.
EtherCAT	Planned	Realized with add-on board

See also:

• Signal path of motor drive
• Pulse burst positioning

Mechanical

Dimension drawing

Property	Value	Units
Dimensions	160 × TBA (~17) × 91 (W×H×D)	mm
Weight	TBA	kg
Drawings	TBA	PDF/IGES/STEP

Note: all mounting holes are 3.2 mm diameter.

Electrical

Power supply

Input voltage	Input current when idle	Input current max
12 - 49 VDC	Typically < 0.4 A	Depends on total power output.

Note: ATOMI doesn't have an input diode for reverse input voltage protection (needed for some switching power supplies).

I/O

Please see ATOMI connectors and pinouts.

Environment

Property	Value	Units
Operating temperature	10 - 70	°C
Storage temperature	-30 - 90	°C
Humidity	0 - 95 non-condensing	%

Connectors & pinouts

Legend

Color
Supply pin
Input pin
Output pin

MX, MY, MZ, MA - Motor and encoder connectors

Pin number	Signal name	Usage	Notes / Specifications
1	Limit	Limit switch, shared for both directions	Internal 2.2 kOhm pull-up resistor
2	CHC / Home	Encoder channel C (index) / home switch	Internal 2.2 kOhm pull-up resistor
3	CHB	Encoder channel B	Internal 2.2 kOhm pull-up resistor
4	CHA	Encoder channel A	Internal 2.2 kOhm pull-up resistor
5	+5 V	5 V supply voltage to encoder	Total 1.5 A current limit for +5 V bus
6	GND	Encoder supply ground / 0 V	Also ground for cable shield
			AC/BLDC motor	Stepper motor	Brush DC motor
7	PH4	Motor phase 4	-	Coil B.2	Armature +
8	PH3	Motor phase 3	W (T)	Coil B.1	Armature -
9	PH2	Motor phase 2	V (S)	Coil A.2	Armature -
10	PH1	Motor phase 1	U (R)	Coil A.1	Armature +

X1 - Granity and SimpleMotion V2 connector

Standard mini-USB connector. Please refer to Granity pages for further instructions.

X2 - Main setpoint connector

X2 is main control and setpoint signal port consisting Global Enable input signal, Global Fault output signal, pulse and direction/PWM setpoint inputs, and digital outputs for servo ready signals. X2 is directly wired to conform most common parallel port style pulse & direction CNC controllers.

Pin number in header	Pin number in D25 cable	Signal name	Typical usage	Notes / Specifications		Pin number in header	Pin number in D25 cable	Signal name	Typical usage	Notes / Specifications
1	1	ENABLE P	Enable all axis	Active low		2	14	Homing	Start homing for all axis	Active low
3	2	HSIN2_X	Direction input X	Direction input for PWM D		4	15	Global_GPO3 P	Global fault output	Active low
5	3	HSIN1_X	Pulse/step input X	PWM setpoint		6	16	PWM2ANA	PWM to analogue converter input	Frequency must be 100 - 10000 Hz
7	4	HSIN2_Y	Direction input Y	Direction input for PWM D		8	17	AUX_IN	Auxilary transistor input	Open-drain buffer gate signal
9	5	HSIN1_Y	Pulse/step input Y	PWM setpoint		10	18	GND	Ground / 0 V	-
11	6	HSIN2_Z	Direction input Z	Direction input for PWM D		12	19	GND		-
13	7	HSIN1_Z	Pulse/step input Z	PWM setpoint		14	20	GND		-
15	8	HSIN2_A	Direction input A	Direction input for PWM D		16	21	GND		-
17	9	HSIN1_A	Pulse/step input A	PWM setpoint		18	22	GND		-
19	10	GPO1_X P	X axis servo ready signal	Active low		20	23	GND		-
21	11	GPO1_Y P	Y axis servo ready signal	Active low		22	24	GND		-
23	12	GPO1_Z P	Z axis servo ready signal	Active low		24	25	GND		-
25	13	GPO1_A P	A axis servo ready signal	Active low		26	N/A	GND		-

Notes:

• Digital inputs accept standard signal levels 2.7 - 5.5 VDC.
• All outputs provide 3.3 V with maximum load of 8 mA.
• All GPO pins have a 180 Ohm series resistor.

^D) PWM can be used with or without direction signal. With PWM setpoint without direction signal 50 % PWM = zero setpoint.

^P) Internal 10 kOhm pull-up resistor.

X3 - Additional setpoint and IO connector

X3 is a second control and setpoint signal port addition to X2. X3 consists of analog setpoint signal inputs and additional digital I/O.

Pin number in header	Pin number in D25 cable	Signal name	Typical usage	Notes / Specifications		Pin number in header	Pin number in D25 cable	Signal name	Typical usage	Notes / Specifications
1	1	GND	GND / 0 V	-		2	14	+5V	+5 V supply	Total 1.5 A current limit for +5 V bus
3	2	GND	GND / 0 V	-		4	15	Global_IO4 P	Reserved for future use	Reserved for future use
5	3	AUX_OUT S	Inverter buffer for AUX_IN	24 V 500 mA open-drain buffer. Active when AUX_IN = HIGH.		6	16	ANA_OUT S	VFD speed control signal	PWM to analogue converter output. Output voltage range 0 - 5 V.
7	4	X_GPI2 P	Disable positive X travel L	Active low		8	17	X_GPI3 P	Disable negative X travel L	Active low
9	5	X_GPO4	X position within limits	Active low		10	18	X_GPO2	X tracking error	Active low
11	6	X_ANAIN	X analogue setpoint input A	0 - 3.3 V A		12	19	Y_GPI2 P	Disable positive Y travel L	Active low
13	7	Y_GPI3 P	Disable negative Y travel L	Active low		14	20	Y_GPO4	Y position within limits	Active low
15	8	Y_GPO2	Y tracking error	Active low		16	21	Y_ANAIN	Y analogue setpoint input	0 - 3.3 V A
17	9	Z_GPI2 P	Disable positive Z travel L	Active low		18	22	Z_GPI3 P	Disable negative Z travel L	Active low
19	10	Z_GPO4	Z position within limits	Active low		20	23	Z_GPO2	Z tracking error	Active low
21	11	Z_ANAIN	Z analogue setpoint input A	0 - 3.3 V A		22	24	A_GPI2 P	Disable positive A travel L	Active low
23	12	A_GPI3 P	Disable negative A travel L	Active low		24	25	A_GPO4	A position within limits	Active low
25	13	A_GPO2	A tracking error	Active low		26	N/A	A_ANAIN	A analogue setpoint input	0 - 3.3 V A

Notes:

• Digital inputs accept standard signal levels 2.7 - 5.5 VDC.
• All GPO pins provide 3.3 V with maximum load of 8 mA.
• All GPI/O pins have a 180 Ohm series resistor.

^A) Setpoint = zero with 50 % input voltage if direction signal is not used.

^L) Limit switches are to be wired with NO (normally open) switch to ground. When a limit switch is triggered, movement to the corresponding direction is disabled.

^P) Internal 10 kOhm pull-up resistor.

^S) Controllable through SimpleMotionV2 bus.

X4 - Power input and STO connector

X4 is a wire terminal for HV DC bus supply and Safe torque off.

Pin number	Signal name	Usage	Notes / Specifications
1	GND	Ground	-
2	STO	Safe torque off	3.3 - 49 V input voltage
3	HV+	Motor power supply, HV DC bus	12 - 49 V, 18 A maximum current through connector

JP1 to JP4 - Encoder passthrough connector

JP1 to JP4 are pin headers for external encoder use.

Pin number	Signal name	Usage	Notes / Specifications
1	+5V	+5 V supply	Total 1.5 A current limit for +5 V bus
2	CHA	Encoder channel A	Direct connection to encoder output signal Internal 2.2 kOhm pull-up resistor
3	GND	GND / 0 V	-
4	CHB	Encoder channel B	Direct connection to encoder output signal Internal 2.2 kOhm pull-up resistor
5	GND	GND / 0 V	-
6	CHC	Encoder channel C	Direct connection to encoder output signal Internal 2.2 kOhm pull-up resistor

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