Aerotech Ndrive CP maintenance replacement

Aerotech Ndrive CP maintenance replacement

In industrial motion control sites, replacing discontinued servo drives and troubleshooting safety circuits often test engineers more than debugging new equipment. Aerotech Ndrive CP is a compact PWM network digital driver, belonging to the high-performance discrete drive product of Automation 3200 motion system. It adopts dual precision floating-point DSP to control digital PID and current loop, supporting brushless motor, brushed motor and stepper motor. All control loop gains, system safety functions and configurations can be set through software parameters. For engineers who are maintaining old equipment, replacing discontinued modules, or expanding multi axis systems, understanding the specifications, wiring, feedback, I/O expansion, PSO laser triggering, and fault logic of Ndrive CP can significantly reduce downtime.

Model and core specifications

The Ndrive CP series includes three common power levels: CP10, CP20, and CP30-S. CP10 peak output 10 A, continuous 5 A; CP20 peak 20 A, continuous 10 A; CP30-S peak 30 A, continuous 10 A, with standard 40 W continuous internal shunt resistor. The motor power input is 14-240 VAC, 50-60 Hz, and the control power is 85-240 VAC, 50-60 Hz. The output voltage range is approximately 20-340 VDC, depending on the AC input and load. 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 160 VDC and 1 mH at 320 VDC. 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 user's power output is 5 VDC, 500 mA. These specifications determine that Ndrive CP is suitable for devices with small to medium power, cost sensitive, and requiring digital closed-loop and FireWire synchronization. If the original device uses a linear driver, it should be noted that the CP is a PWM power level, and the noise and heating characteristics are different; If lower noise is required, linear series should be evaluated.

Key points of power supply and wiring

Ndrive CP requires two power connections: control power and motor power. Control the power supply to TB106, requiring 85-240 VAC, with a minimum of 85 VAC to function properly. AC1 has a fuse inside, AC2 can be connected to the neutral line, and if connected to other voltage sources, an external 2A delay fuse is required. The control power supply is used to maintain communication when the motor power is removed, such as in an emergency stop state. The motor power supply is connected to TB102, and the internal fuses of AC1 are CP10 5 A and CP20/30 10 A. An external maximum delay fuse or circuit breaker of 15 A is also required. The motor power supply is 14-240 VAC and can be configured in single-phase or three-phase, but the CP manual mainly describes single-phase input.

To reduce noise, it is recommended to install line filters before controlling the power supply and motor power supply, and to be as close as possible to the driver. CE compliance typically requires external filters, such as Schaffner FN2080 or Aerotech UFM-ST. UFM-ST input and output 0-240 VAC, maximum continuous current 8 Arms convection cooling, 10 Arms forced air cooling, internal 10A fuse. 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. Encoders and signal lines must be physically isolated from motors, AC power sources, and other power lines.

If it is necessary to reduce the motor voltage or isolate, an external transformer can be used. TV0.3-28-56-ST can generate 28 or 56 VAC from 115/230 VAC, and after rectification, obtain 40 or 80 VDC bus. The TM3 and TM5 transformer modules can provide 300 W or 500 W power respectively for up to 4 drivers. TV0.3-28 generates 28 VAC corresponding to 40 VDC, TV0.3-56 generates 56 VAC corresponding to 80 VDC, TV1.5, TV2.5, and TV5 are 1.5/2.5/5 kVA isolation transformers. When using an isolation transformer, grounding the AC2 input tap can reduce electrical and audible noise and improve servo performance.

Motor connection and phase adjustment

Ndrive CP 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.

Feedback interface and limit

The motor feedback connector J103 is a 25 pin D-type, including an encoder, limit Hall、 Thermistor, 5V power supply, 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.

The absolute encoder supports reading position and fault information through serial data streams, and supports interfaces such as EnDat and Resolute. Encoder fault input J103 pin 23 can be used for encoders with fault output, and the effective status can be parameterized. 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. 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. The effective limit state can be selected by software. If the limit direction is opposite, switch the CW and CCW wiring. The brake output J103 pins 13 and 25 can be connected to the brake power supply TB103. TB103 provides onboard solid-state brake relays with a maximum voltage of 24 VDC and 2.5 A, with a turn-on time of approximately 3.2 ms and a turn off time of approximately 0.1 ms. The brake power supply must have an external fuse, and the brake coil must be equipped with a variable resistor or suppression circuit. If using - IO board mechanical relays, do not use TB103 solid-state relays at the same time.

Auxiliary I/O, PSO, and expansion options

The auxiliary I/O connector J104 provides 1 analog input, 6 digital inputs, 1 analog output, 4 digital outputs, and an auxiliary RS-422 encoder interface. Digital output optical isolation, maximum 24V, 60 mA/channel, can be sourced or sunk, but the same group must be fully sourced or fully sunk. Digital input optical isolation, 5-24 V, approximately 1 mA at+5 V and 6 mA at+24 V. High speed input 12-13 for data acquisition, 5 V, 10 mA, delay 50 ns. Analog output 0 is ± 10 V, 16 bit, 305 μ V resolution. Differential analog input 0 is ± 10 V, 16 bit, 305 μ V. The maximum frequency of the auxiliary encoder is 10 MHz, with 40 million counts/s after x4, and can be used for handwheel, master-slave, or dual feedback. The auxiliary encoder can also be used to echo the main encoder or as a PSO output, but it cannot echo the main encoder under - MXU.

PSO position synchronization output is used for laser triggering or peripheral timing. Output at pins 19 and 20 of Aux Marker/PSO on J104. Single axis tracking up to 16.6 MHz, standard feedback up to 40 MHz orthogonal output, PSO up to 12.5 MHz output, trigger delay of 160 ns. PSO is not compatible with - MXU, but can be used with - MXH and square wave encoders. 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. If PSO does not trigger, first confirm whether MXU is optional; If - MXU is used, PSO is not available.

In terms of expansion options, the IO board has added 16 digital inputs, 16 digital outputs, 1 12 bit analog input, 1 16 bit analog output, and a brake relay. Digital output up to 24 V, 60 mA/channel, input 5-24 V. Analog input 12 bit, 4.88 mV resolution, analog output 16 bit, 305 μ V. -MXU provides the highest x1024 encoder multiplier (4096 after x4), but there is no real-time output. -S is the internal shutout, 50 Ω, 40 W continuous, 400 W peak for 5 seconds. -EXTSHUNT is an external shut-down connection that opens at approximately 380 VDC on the internal bus, making it suitable for high inertia or frequent braking systems; Mutually exclusive with - S. External shuts need to be provided by the user. It is recommended to use a 50 Ω minimum, 300 W, 16 AWG high-temperature wire with a control board F1 fuse of 2.5 A. If the system's regenerative energy exceeds the energy that can be stored in the internal bus capacitor (approximately 71.3 J for a 160 V bus and 25.2 J for a 320 V bus), shuts must be calculated and installed.

Engineering process for replacing discontinued modules

When replacing the discontinued Ndrive CP or other brand PWM servo modules, it is recommended to follow the following sequence:

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

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

Confirm power supply: CP requires 85-240 VAC control power supply and 14-240 VAC motor power supply. If the original system is a DC bus, MP or ML needs to be evaluated; if low-noise linear output is required, CL or HL should be selected.

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.

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; Avoid - MXU when PSO is needed. When external regeneration is required, select - EXTSHUNT, and when internal shutdown is required, select - S.

Mechanical and heat dissipation: The CP weighs approximately 1.63 kg and requires 25 mm of free air space and 100 mm of cable space in front. Working temperature 0-50 ° C, storage -30-85 ° C, humidity 80% to 31 ° C, altitude 2000 m, pollution level 2, for indoor use only. The PWM driver generates significant heat, and installing it on a large metal plate or adding a fan can improve heat dissipation.

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 faults and troubleshooting

No display or PWR flashing when powered on: Check if the control power supply 85-240 VAC is normal and if the 5V user power supply is overloaded. The PWR 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, the TB101 input must be driven, otherwise an ESTOP fault will be triggered.

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.

Bus overvoltage: PWM drivers may feedback energy during motor braking. If bus overvoltage is frequently reported, it is necessary to evaluate the regenerative energy and install an internal - S or external - EXTSHUNT. External shuts must be selected and cooled correctly, as their temperature may exceed 70 ° C, carry lethal voltage, and must be enclosed and shielded.

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 CP 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 to achieve controlled stop and communication maintenance.

Brake abnormality: TB103 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, do not use TB103 at the same time. Check the JP1 jumper configuration and confirm switching between Brake+or Brake -.

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.

FAQ

What is the relationship between Ndrive CP and CP10?

CP is the series name, CP10 is a 10 A peak and 5 A continuous power level. CP20 is 20 A/10 A, CP30-S is 30 A/10 A and has an internal damper.

Does CP support rotation?

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

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

No. PSO is not available when CP uses MXU. If both encoder multiplication and PSO are required, a model that supports - MXH should be selected or the function should be reassigned.

How to choose - S and - EXTSHUNT?

-S is an internal 50 Ω, 40 W continuous, 400 W peak for 5 seconds shutdown; -EXTSHUNT is an external shut-down connection, suitable for larger regenerative energy. The two are mutually exclusive. First, calculate the regenerative energy and peak power.

Can CP directly replace other brands of servo drives?

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