Aerotech Ndrive MP Ultra Compact PWM Digital Servo Driver

Aerotech Ndrive MP Ultra Compact PWM Digital Servo Driver

In precision motion control equipment, space is often the scarcest resource. When there is only narrow guide rail space left in the control cabinet, or when the mobile platform requires the driver to move together with the mechanism, traditional large volume servo drives are difficult to handle. The Aerotech Ndrive MP is a network digital driver designed for such ultra compact scenarios. It belongs to the Automation 3200 motion system, using PWM power level, supporting brushless, brushed, and stepper motors, with digital current loop, speed loop, and position loop closure, and can achieve multi axis synchronization through the FireWire network. For engineers who are maintaining old equipment, replacing discontinued micro drives, or expanding multi axis systems, understanding the specifications, power supply, feedback PSO、 Expanding options and fault logic can significantly reduce downtime.

Positioning and core specifications

The Ndrive MP is the smallest member of the Ndrive family, with a width of approximately 41.1 mm, a height of approximately 141.2 mm, and a standard weight of only 0.454 kg. After installing - IO or - MXU, it weighs approximately 0.544 kg. It uses a dual precision floating-point DSP to control the digital PID and current loop, and all control loop gains, system safety functions, and configurations can be set through software parameters. Drivers provide deterministic behavior, automatic recognition, and convenient software settings, suitable for mobile or embedded devices with extremely limited space and DC power supply.

In terms of electrical specifications, the Ndrive MP motor power input is 10-80 VDC, the control power supply is 24-80 VDC (± 10%), and the maximum current of the control power supply is 1 A. The output voltage range is 10-80 VDC, the peak output current is 10 A (for 1 second), and the continuous output current is 5 A. The PWM switching frequency is 20 kHz, and the maximum bandwidth of the power amplifier is 2500 Hz, which can be selected by software. The minimum load inductance is 0.1 mH at 80 VDC. The user power output is 5 VDC, 500 mA. The efficiency is about 85% -95%, and the higher the output power, the higher the efficiency.

The protection functions include output short circuit, peak overcurrent, DC bus overvoltage, RMS overcurrent, over temperature, control power undervoltage, and power stage bias undervoltage. Optical and transformer isolation are used between the control and power stages. The working environment temperature is 0-50 ° C, the storage temperature is -30-85 ° C, the humidity is up to 80% below 31 ° C, and then linearly decreases to 50% when it reaches 40 ° C. It is non condensing, with an altitude of up to 2000 meters and a pollution level of 2. It is only suitable for indoor use. MP complies with CE, NRTL safety certification, and RoHS 2 directive.

Unlike large drives such as HPe and HLe, Ndrive MP does not offer internal shutdowns or external shutdowns options. This means that under frequent braking or high inertia loads, regenerative energy must be processed by external systems, otherwise it may trigger DC bus overvoltage. If the original system relies on internal shuts during replacement, additional evaluation is required.

Power supply and external power supply options

Ndrive MP requires two power connections: control power and motor power. Control the power supply to TB103, requiring 24-80 VDC, with fuses inside the DC+. The motor power supply is connected to TB102, requiring 10-80 VDC, continuous 5A, and peak 10A. Both power supplies must be connected simultaneously to function properly. If the motor power supply is cut off by the emergency stop circuit, the control power supply can still maintain communication and encoder power supply, achieving controlled stop and status monitoring.

To reduce noise, the DC+and DC - wires of the control power supply and motor power supply should be twisted and wound around the ferrite core, typically around 6 turns, but not around the ground wire. The motor cable should use shielded cable, and the shielding layer should be connected to the metal D-type connector back shell or rack ground. The motor leads can be equipped with ferrite beads, such as Fair Rite # 2643002402 and # 2643250402. The encoder and signal lines must be physically isolated from the motor and power lines.

In terms of external power supply, the TM3 transformer module can provide 300 W power for up to 4 drivers and must be configured for ± 40 VDC or ± 80 VDC output. PS-MP is a DIN rail mounted DC power supply that supports up to 4 axes. PS-12048-A is a 120 W, 48 VDC, 100-120 VAC input; PS-12048-B is 120 W, 48 VDC, 200-240 VAC; PSP-24048 is 240 W, 48 VDC, automatically adjustable 100-240 VAC; PSP-480D48-A and PSP-480S48-B are 480 W, 48 VDC. The user must provide a 10A, 250 VAC fuse or circuit breaker to protect the AC input, and connect the AC and protective ground using a 16 AWG, 300 V wire.

If using an isolated DC power supply, the DC should be connected to the protective ground at the power supply. All grounding must comply with local electrical safety requirements. A 25mm free air space should be left inside the control cabinet, and a 100mm cable space should be left in front. Installing it on a metal plate or adding a fan can improve heat dissipation.

Motor wiring and phase adjustment

Ndrive MP can control brushless, brushed, and stepper motors. When wiring the brushless motor, the A/B/C of the motor should be connected to the A/B/C of TB102, and the motor frame and shield should be grounded. Hall signal connected to J103: Hall A pin 10, Hall B pin 5, Hall C pin 11. The forward motion command should cause the motor to rotate clockwise when viewed from the mounting flange. If the direction is opposite, any two-phase motor wires can be exchanged. Brushless motor commutation relies on Hall and back electromotive force alignment. If using non Aerotech motors, it is recommended to confirm using oscilloscope method or power on phase method. The oscilloscope method requires a dual channel oscilloscope, a 5 V power supply, and six 10 k Ω resistors. Connect the three phases of the motor to the Wye neutral point, manually rotate clockwise, and observe the opposite electromotive forces and Hall state. The correct Hall state should be aligned with the back electromotive force, and if necessary, corrected with the Commutation Offset parameter.

When wiring a brushed motor, connect the positive motor lead to OA and the negative lead to OC. To determine the phase, use a voltmeter to connect the motor lead and manually rotate clockwise. If the voltage is negative, swap the probe until the reading is positive. The positive probe is connected to the positive motor lead, connected to OA; the other lead is connected to OC. When wiring the stepper motor, pay attention to the common connection and two-phase winding. When equipped with an encoder, the forward motion command should cause the motor to rotate clockwise; If the opposite is true, exchange the motor leads. The direction of the limit switch is related to the direction of motor rotation, and phase errors can cause collision with the limit.

The motor feedback connector J103 is a 25 pin D-type, including an encoder, limit Hall、 Thermistor, 5V power supply, analog input, and optional braking. The main encoder interface accepts RS-422 differential line driven orthogonal signals, with a maximum frequency of 10 MHz. After x4 orthogonal decoding, it can reach 40 million counts/s. If - MXU is selected, the main encoder can be configured as an analog sine encoder input, with a maximum input frequency of 200 kHz and an amplitude of 0.6-2.25 Vpk Vpk. The software can select an interpolation factor of 4096. The gain, offset, and phase balance of the analog encoder can be adjusted through parameters, and it is recommended to use Feedback Tuning from Digital Scope for automatic optimization.

Thermistor input J103 pin 2 is used for motor over temperature detection. Normally, it is about 100 Ω, but exceeding about 1 k Ω triggers an over temperature fault. Encoder fault input J103 pin 23 can be used for encoders with fault output, and the effective status can be parameterized. Hall input J103 pins 5, 10, 11, if the status (0,0,0) or (1,1,1) is invalid, it will trigger a Hall fault. Limit input J103 pins 12 (CW), 24 (CCW), 22 (Home), accept 5-24 VDC. Positive motion is stopped by CW limit, and negative motion is stopped by CCW limit. If the limit direction is opposite, switch the CW and CCW wiring. Brake output J103 pins 13 and 25 can be connected to - IO board solid-state relays and TB201. Analog input 0 is located at pins 8 and 19 of J103, with a differential of ± 10 V, 12 bits, and a resolution of 4.88 mV.

Auxiliary I/O, PSO, and - IO expansion

The standard configuration of Ndrive MP includes 1 orthogonal encoder input, Home and limit inputs, 1 12 bit differential analog input, and ESTOP input. Digital and analog I/O can be increased through the - IO expansion board. -The IO board provides 8 optical isolated digital inputs, 8 optical isolated digital outputs, 1 12 bit analog input, 1 16 bit analog output, a second encoder channel, and a brake relay. The maximum digital output is 24 V, 60 mA/channel, which can be sourced or sunk, but the same group must be configured uniformly. Digital input 5-24 V, approximately 1 mA at+5 V and 6 mA at+24 V. Analog output 1 is ± 5 V, 16 bit, 153 μ V resolution. Analog input 1 is ± 10 V, 12 bits, 4.88 mV. The auxiliary encoder interface is located in J201, with a maximum frequency of 10 MHz and 40 million counts/s after x4. It can be used for handwheel, master-slave, or dual feedback.

PSO position synchronization output is used for laser triggering or peripheral timing. The PSO output of MP is on pins 1 and 6 of Aux Marker in J201. Single axis tracking up to 16.6 MHz, PSO output up to 12.5 MHz, trigger delay of 160 ns. PSO is not compatible with MXU; If - MXU is used, PSO is not available. The auxiliary encoder interface can be configured as either encoder input or PSO output, but cannot be used simultaneously. If SIN/COS is used as the encoder input, MRK cannot be used as the PSO output. Since MP does not have other PSO output methods, if the auxiliary encoder is configured as input, PSO triggering cannot be performed. It is recommended to use RS-422 line receiver or optical isolator for long cables or noisy environments, and to be close to the receiving end.

ESTOP input TB101 is used to monitor external safety circuits, with an input of 5-24 V. If ESTOP is enabled in FaultMask, this input must be driven to avoid faults. Emergency stop should cut off the motor power supply while maintaining the control power supply to achieve controlled stop and communication maintenance. If connected to a relay or inductive load, RC network or varistor suppression should be added.

Engineering process for replacing discontinued modules

When replacing discontinued Ndrive MP or other brands of miniature servo modules, it is recommended to follow the following sequence:

Record the original module parameters: model, peak/continuous current, bus voltage, control power supply, motor power supply, feedback type, communication interface, I/O quantity, PSO capability, encoder multiplier, brake output, ESTOP logic, size, and heat dissipation.

Match motor: confirm brushless, brushed, or stepper; Confirm pole pairs Hall、 Encoder resolution, analog encoder, or absolute encoder. If the original system uses a rotary converter and MP does not support it, it should be switched to models with RDP such as HPe/HLe.

Confirm power supply: MP requires 24-80 VDC control power supply and 10-80 VDC motor power supply. If the original system is powered by AC, an external DC power source such as PS-MP or TM3 needs to be added. If the original system relies on internal shutdowns and MP does not provide them, external processing of regenerated energy is necessary.

Confirm feedback and network: FireWire topology, S1 device number, controller axis mapping. Multiple drives must have a unique communication channel, usually numbered sequentially starting from 1. FireWire has a speed of 400 Mbps, and if the cable exceeds 4.5 meters, a repeater is required.

Confirm I/O and PSO: select - IO when standard I/O is insufficient; select - MXU when encoder multiplication is required, but note that PSO is not available; When PSO is required, avoid - MXU or use - IO board to assist the encoder channel.

Mechanical and heat dissipation: MP has a small volume, but still requires heat dissipation when outputting continuously for 5 A. Installing on a metal plate or adding a fan can reduce temperature rise. The working temperature should not exceed 50 ° C, and the chassis temperature may exceed 70 ° C. Pay attention to burns.

Power on test: Do not connect the motor first, check the LED, FireWire, and control power supply ESTOP； Connect the motor for low-speed testing of phase, feedback direction, limit, and PSO; Finally, gradually load and check the current, temperature, and tracking error.

Common troubleshooting

No display or CTL flashing when powered on: Check if the control power supply 24-80 VDC is normal and if the 5V user power supply is overloaded. The CTL light keeps flashing and not working, which may be due to excessive 5V current or low control power supply voltage.

ENB/FLT red light or flashing: ENB/FLT green indicates axis enable, red indicates fault, and alternating red and green indicates enable and fault. Check for FaultMask, ESTOP, Hall faults, encoder faults, RMS overcurrent, overheating, and bus overvoltage. If the ESTOP bit is enabled, it must drive the TB101 input.

Motor runaway or shaking: Check if the encoder Sin/Cos is connected in reverse, if the feedback direction is incorrect, and if the commutation phase is correct. The brushless motor does not rotate, and the common reason is that the relative order of motor A/B/C and Hall A/B/C is incorrect. Swap any two-phase motor wires or Hall wires and perform phase testing again. The analog encoder needs to check the gain, offset, and phase balance.

Over current or over temperature: Check if the acceleration is too fast, if the load is stuck, if the motor is short circuited, if the gain is too high, and if the commutation is correct. Reduce continuous current, improve ventilation, and check if the ambient temperature exceeds 50 ° C. MP does not have internal shutdowns, and if frequent braking occurs, external treatment of regenerative energy is required.

Bus overvoltage: The motor power supply of MP is 10-80 VDC, and regenerative energy may cause the bus voltage to rise. If bus overvoltage is frequently reported, external braking resistors or regeneration modules should be added, and it should be confirmed that the power supply can absorb feedback energy.

Communication failure: Check the FireWire cable, ports, node sequence, and S1 device number. FireWire speed of 400 Mbps, recommended star daisy chain. If the cable exceeds 4.5 meters, a repeater is required. After replacing the drive, confirm that the firmware version and configuration file are compatible.

PSO not triggered: Confirm if MXU is optional. The PSO of MP is not compatible with - MXU. Check the PSO output wiring, line receiver or opto isolator, trigger position, and controller configuration. The maximum output of PSO is 12.5 MHz, with a single axis delay of 160 ns.

ESTOP alarm: TB101 input 5-24 V, driven by external fail safe emergency stop circuit. If connected to a relay or inductive load, RC network or varistor suppression should be added. Emergency stop should cut off the motor power supply while maintaining the control power supply.

Brake abnormality: TB201 solid-state relay has a maximum voltage of 24 VDC and 2.5 A. The brake power supply must have an external fuse, and the brake coil needs to be suppressed. If using - IO mechanical relays, be careful not to conflict with solid-state relays.

In terms of maintenance, the chassis, cooling vents, cables, and connectors should be checked monthly. Turn off the power during cleaning, use a dry soft cloth, and if necessary, slightly wet water or isopropanol. Do not allow liquids to enter the connector. Internal high voltage may still exist after a power outage, and maintenance must be carried out by qualified personnel. Control board fuse F1 is for controlling power supply 2A, F2 is for busbar 5A, and F1 is welded to the board. LED includes ENB/FLT, MARK, CTL, POS, which can quickly determine the enable, fault, marking, and in place status.

FAQ

What is the difference between Ndrive MP and HPe?

MP is an ultra compact DC powered driver with a 10-80 VDC motor power supply, a 24-80 VDC control power supply, 10 A peak, and 5 A continuous; HPe is an AC powered high-performance PWM driver that covers 10-30 A peak, 14-240 VAC input, and supports more expansion and rotation options.

Does MP support rotation?

I won't support it. When rotation is required, HPe, HLe, or HL should be selected and RDP options should be configured.

Can MP's PSO and - MXU be used simultaneously?

No. PSO is not available when MP is using MXU. If PSO is required, avoid - MXU or use - IO board to assist the encoder channel.

Does MP have an internal shutout?

No. MP does not provide internal or external shutdown options. Frequent braking or high inertia loads require external processing of regenerative energy.

Can MP directly replace other brands of micro servo drives?

It cannot be judged solely based on size and current. It is necessary to verify the motor type, feedback, commutation, FireWire network, I/O, PSO, ESTOP, and regeneration processing.

What external power sources does MP support?

TM3 transformer module or PS-MP DIN rail DC power supply can be used. PS-MP offers versions such as 120W, 240W, and 480W, supporting up to 4 axes.