Aerotech Ndrive Linear Drive Selection

Aerotech Ndrive Linear Drive Selection

In the field of precision motion control, linear servo drives have always been the preferred choice for optical inspection, semiconductor processing, nanopositioning, and laser microfabrication due to their low noise, zero alternating distortion, and ultra-high bandwidth. The linear series in the Aerotech Ndrive family includes Ndrive HLe, Ndrive CL, and Ndrive ML, which share the digital architecture of the Automation 3200 motion controller and achieve deterministic communication and multi axis synchronization through the FireWire network. For engineers who are maintaining old equipment, replacing discontinued linear drive modules, or expanding multi axis systems, understanding the specification differences, feedback capabilities, I/O expansion, PSO laser triggering, and ordering options of these three drives is key to reducing downtime and avoiding selection errors.

Ndrive linear series positioning

The Ndrive linear series is a high-performance discrete drive used to control brushless motors, brushed DC motors, stepper motors, and voice coil motors. They use digital current loop, velocity loop, and position loop closure, based on dual precision processors, to generate extremely smooth motion curves. The servo response is optimized through up to eight second-order loop shaping filters, precise time aligned feedforward, and other proprietary technologies, with a maximum closed-loop rate of 20 kHz. The linear power stage has no PWM switching noise, so the EMI/RFI emission is extremely low, and the speed regulation and position stability are excellent.

Ndrive HLe is the most feature rich linear drive in the series, supporting rotary or encoder feedback, with optional 1 to 3-axis position synchronous output, automatic brake control, digital and analog I/O expansion, absolute encoder interface, 1 or 2-channel rotary interface, and dedicated Ethernet port for third-party I/O expansion. Ndrive CL and Ndrive ML are designed for cost sensitive or space limited applications, retaining linear power levels and FireWire networks but simplifying some scalability. Any Ndrive combination can be connected to the Automation 3200 FireWire network, configured on an axis for flexible expansion.

Comparison of HLe, CL, and ML cores

From the perspective of current and bus, Ndrive HLe covers peak voltage of 10-20 A, continuous voltage of 5-10 A, and bus voltage of ± 40 to ± 80 VDC; Ndrive CL has a peak of 10 A, continuous 5 A, and a bus voltage of ± 40 VDC; Ndrive ML also has a peak of 10 A, continuous of 5 A, and a bus voltage of ± 40 VDC. All three are linear power levels with a minimum load inductance of 0, suitable for low inductance linear motors and voice coil motors.

In terms of power supply, the HLe motor power supply is a 2-phase AC, 115/230 VAC, 50/60 Hz, factory configured; Control power supply 85-240 VAC. The power supply of CL motor is a 56 VAC center tap transformer with two 28 VAC windings; Control power supply 85-240 VAC. The ML motor power supply is DC, with a maximum of ± 40 VDC; Control power supply 18-36 VDC. This means that ML is more suitable for mobile or embedded devices powered by DC, while HLe and CL are suitable for cabinets isolated by AC or transformers.

In terms of I/O, HLe and CL have similar standard configurations: 4 optically isolated digital outputs, 6 optically isolated digital inputs (including 2 high-speed inputs), 1 16 bit differential analog input, and 1 16 bit single ended analog output. ML standard I/O is limited, with only one 16 bit differential analog input, and digital I/O needs to be obtained through an expansion board. In terms of expanding I/O, HLe can add 16 digital inputs, 16 digital outputs, 3 16 bit analog inputs, and 3 16 bit analog outputs; CL can add 16 digital inputs, 16 digital outputs, 1 12 bit analog input, and 1 16 bit analog output; ML can add 8 digital inputs, 8 digital outputs, 1 16 bit analog input, and 1 16 bit analog output. HLe also supports Ethernet connection to third-party I/O, while CL and ML do not provide Ethernet.

There are significant differences in PSO capabilities: HLe standard single axis PSO, optional dual axis and three-axis; CL and ML only support single axis PSO. In terms of encoder multiplication, HLe can choose MXH, with a maximum of x65536 and real-time orthogonal output; CL can choose MXU, up to x8192, but there is no real-time orthogonal output; ML can choose MXU up to x4096 or MXH up to x65536 with real-time orthogonal output. The rotary interface is only available in HLe, providing 1 or 2 channels and 16 bit resolution. The absolute encoder interface HLe supports Renishaw Resolute BiSS, EnDat 2.1, and EnDat 2.2. Automatic braking control is standard on HLe, 24 V @ 1 A; CL and ML are optional. ESTOP are all standard 24V optically isolated inputs.

Ndrive HLe Detailed Capability

The Ndrive HLe has three basic models: 10-40, 20-40, and 10-80. 10-40 is a 10 A peak, 5 A continuous, ± 40 VDC bus; 20-40 is a 20 A peak, 10 A continuous, ± 40 VDC bus; 10-80 is a 10 A peak, 5 A continuous, ± 80 VDC bus. The motor power supply is 115/230 VAC, 50/60 Hz, factory configured; Control the power supply to 85-240 VAC for logic circuits and 'keep active' power supply.

In terms of feedback interface, the main encoder input supports 32 MHz square wave standard or 500 kHz sine wave (with MXH). The auxiliary encoder input is a 32 MHz square wave. Encoder multiplication can reach x65536 through MXH and supports real-time orthogonal output. The absolute encoder supports Renishaw Resolute BiSS, EnDat 2.1, and EnDat 2.2. The rotary converter interface can choose 1 or 2 channels, with a 16 bit resolution and a carrier frequency of 10 kHz, 7.5 kHz, or 5 kHz, corresponding to options such as RDP1-10K, RDP1-7.5K, RDP1-5K, RDP2-10K, RDP2-7.5K, and RDP2-5K.

The I/O expansion board provides 16 optical isolated inputs, 16 optical isolated outputs, 3 16 bit analog inputs, 3 16 bit analog outputs, and brake relays. The high-speed data capture delay is about 50 ns. Automatic braking control is standard, 24 V @ 1 A. ESTOP is a standard 24V optically isolated input. PSO standard single axis, optional dual axis or three-axis; The second encoder input of the dual axis PSO can be obtained through AUX connection or SSI Net, while the three-axis PSO requires I/O options to provide feedback connection for the three-axis encoder. PSO optoelectronic isolators can be optionally - PSOPTO2 (<+15 V, high speed, low current, 6N136), - PSOPTO3 (<+30 V, low speed, high current, 4) N33）、-PSOPTO4（TIL117-M，40 kHz，5–25 VDC，50 mA）， And - PSOAH active high output. Ethernet Options - ENET provides 10/100 BASE-T ports for third-party I/O expansion. The current loop update rate is 20 kHz, the servo loop update rate is 8 kHz, the power amplifier bandwidth software is optional, the operating temperature is 0-50 ° C, the storage is -30-85 ° C, and the weight is approximately 10.36 kg (22.8 lb).

Differentiation between Ndrive CL and ML

Ndrive CL is positioned as a cost sensitive linear drive, model CL10-40. It supports brushed and brushless motors, 10 A peak, 5 A continuous, ± 40 VDC bus. The control power supply is 85-240 VAC, and the motor power supply is a 56 VAC center tap transformer with two 28 VAC windings. Standard I/O includes 4 optically isolated digital outputs, 6 optically isolated digital inputs, 1 16 bit differential analog input, and 1 16 bit single ended analog output. Expand I/O to include 16 digital inputs, 16 digital outputs, 1 12 bit analog input, and 1 16 bit analog output. PSO is only single axis. Encoder multiplier with optional MXU, up to x8192, but without real-time orthogonal output. Rotary, Ethernet, and absolute encoder interfaces are not provided. Automatic braking control is optional. ESTOP is a standard 24V optical isolation. Current loop 20 kHz, servo loop 8 kHz, minimum load inductance 0, operating temperature 0-50 ° C, weight approximately 3.54 kg (7.8 lb), width 103.7 mm, height 265.2 mm.

Ndrive ML is the smallest linear drive in the series, model ML10. It supports brushed and brushless motors, 10 A peak, 5 A continuous, ± 40 VDC bus. The motor power supply is DC, with a maximum of ± 40 VDC; Control power supply 18-36 VDC. Standard I/O only has one 16 bit differential analog input, while digital I/O requires an expansion board. Extended I/O includes 8 digital inputs, 8 digital outputs, 1 16 bit analog input, and 1 16 bit analog output, and supports auxiliary encoders sin/cos/mkr and PSO outputs. PSO is only single axis. Encoder multiplication options include MXU up to x4096 or MXH up to x65536 with real-time orthogonal output. The main encoder input supports 32 MHz square wave standard or 2 MHz sine wave (MXU or MXH). Automatic braking control is optional, with ESTOP standard 24V optical isolation. Current loop 20 kHz, servo loop 8 kHz, minimum load inductance 0, operating temperature 0-50 ° C, weight approximately 1.0 kg, width 92.1 mm, height 141.0 mm. ML is suitable for mobile devices or embedded multi axis systems with extremely limited space and DC power supply.

Ordering Options and Configuration Analysis

The ordering information for Ndrive HLe typically consists of a base, output current, control options, rotary options, and line voltage options. For example, HLe 20-40-X-ENET RDP1-10K. The base is HLe 10-40-X, 20-40-X, or 10-80-X. Line voltage options: A is 115 VAC, B is 230 VAC, C is 100 VAC, and D is 200/208 VAC. The control options include: - I/O expansion board, - DUALPSO dual axis PSO, - TRIPLEPSO three-axis PSO, - PSOPTO2, - PSOPTO3, - PSOPTO4, - PSOAH, - MXH encoder multiplier, - ENET Ethernet. The rotary options include RDP1-10K, RDP1-7.5K, RDP1-5K, RDP2-10K, RDP2-7.5K, and RDP2-5K.

The order for Ndrive CL is CL10-40, with control options - I/O and - MXU. The order for Ndrive ML is ML10, with control options - I/O, - MXU, and - MXH. Attention should be paid when selecting: When CL and ML use integrated MXU, PSO is not available. If both encoder multiplication and PSO are required, HLe's MXH should be selected or the function should be reassigned. HLe's MXH supports real-time orthogonal output, suitable for multi axis PSO and encoder cascading. The MXU of CL and ML does not have real-time output, making it suitable for situations where only resolution needs to be increased without the need to output encoder signals.

Engineering process for replacing discontinued modules

When the original linear servo drive is discontinued or limited in supply, it is not enough to only consider the installation size and current. Suggest following the following process to proceed:

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

Match motor: confirm brushless, brushed, stepper or voice coil; Confirm pole pairs, Hall signals, encoder resolution, rotation or Inductosyn. If the original system uses a rotary converter, the HLe+RDP option should be selected; If using an analog sine encoder, choose MXH.

Confirm power supply: HLe and CL require AC motor power supply, ML requires DC motor power supply. CL requires a 56 VAC center tap transformer. The ML control power supply is 18-36 VDC. If the original system is 115/230 VAC, HLe is the most direct.

Confirm feedback and network: FireWire topology, device number, controller axis mapping. When Ethernet I/O is required, select HLe ENET.

Confirm I/O and PSO: Select - I/O when standard I/O is insufficient; Dual axis/three-axis laser trigger selection - DUALPSO/- TRIPLEPSO; PSO output optoelectronic isolators are selected according to speed/voltage - PSOPTO2/- PSOPTO3/- PSOPTO4; Real time encoder output selection - MXH is required.

Mechanical and Heat Dissipation: HLe weighs approximately 22.8 lb, CL is approximately 7.8 lb, and ML is approximately 1.0 kg. Linear drives have low efficiency and generate significant heat, requiring sufficient heat dissipation space. The ambient temperature should not exceed 50 ° C, and the chassis temperature may be high.

Power on test: Do not connect the motor first, check the logic power supply LED、FireWire、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.

If the original device uses PWM drivers, upgrading to linear drivers can achieve lower noise and higher bandwidth, but it is necessary to evaluate heat generation, regenerative energy, and heat dissipation. If the original device uses Ndrive HL, HLe is its successor or parallel model with stronger functionality, supporting more I/O, Ethernet, rotary and absolute encoders. CL and ML are suitable alternatives for cost or space constraints, but cannot fully cover HLe's multi axis PSO, rotary, and Ethernet capabilities.

Troubleshooting and Maintenance

The faults of linear drives are usually concentrated in feedback, power supply, heat dissipation, communication, and configuration conflicts.

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.

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. Linear drives require high heat dissipation, and overheating can be triggered when the ambient temperature exceeds 50 ° C, air ducts are blocked, or continuous current is too high. Ventilation should be improved and continuous current should be reduced.

Bus overvoltage: Linear drives do not have internal shutdowns, and regenerated energy must be processed externally. If the motor brakes frequently or is lowered vertically, an external shunt or regenerative resistor needs to be added.

Communication failure: Check FireWire cable, ports, node sequence, and device number. FireWire networks are sensitive to topology and cable quality, and it is recommended to use a star daisy chain with up to 16 drivers per chain and up to 32 axes. After replacing the drive, confirm that the firmware version and configuration file are compatible.

PSO not triggered: Confirm if the PSO option is correct. PSO is not available when CL and ML use MXU. HLe dual axis/three-axis PSO requires - DUALPSO or - TRIPLEPSO, and may require - I/O to provide encoder feedback connections. Check the PSO output wiring, optoelectronic isolation options, trigger position, and controller configuration.

ESTOP alarm: The ESTOP input requires an external fail safe circuit, with an input of 5-24 V. If it exceeds this range, a series resistor current limiting is required. If ESTOP is enabled in FaultMask, this input must be driven to avoid faults. Check the external safety relay and 24V logic.

Abnormal braking: HLe automatic braking control standard, CL/ML optional. Check the specifications of the brake relay, suppression diode or RC network, brake power supply, and J207 brake pin. Inductive loads must be suppressed, otherwise they may damage the relay contacts.

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. The internal high voltage may still exceed 60 V after a power outage, and maintenance must be carried out by qualified personnel.