Aerotech Ndrive Linear Drive Selection

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.