Aerotech NDrive HL linear drive maintenance replacement

MXH is closely related to PSO. When using - DUALPSO or - TRIPLEPSO, if the encoder data rate is too high, the PSO tracking rate should be limited to 5 MHz through CfgFbkEncMxhQuadDiv or PSOTRACK SCALE while maintaining full resolution of the servo loop. SSI Net J302/J303 provides two bidirectional RS-422 channels for daisy chain encoder signals, sending the second/third axis encoders to drivers with - DUALPSO/- TRIPLEPSO. The maximum data rate of SSI Net is 20 MHz, requiring the use of a dedicated SSI Net cable and configuration of parameters such as PsoSsiConfig and PsoSsi2Config. If the original device uses multi axis laser triggering, these cables and parameter configurations must be retained during replacement.

Rotary input and - RDP options

NDrive HL optional - RDP rotary input, providing two industry standard rotary or Inductosyn channels, each channel can be independently configured as a rotary or Inductosyn input. The standard reference output frequency is 10 kHz, which can also be configured at the factory as 5 or 7.5 kHz. Sine and Cosine feedback signals should be adjusted to 2 V RMS (2.8 V peak) through CfgFbkRDGain. The rotary transformer can be physically aligned with the motor through MSET CNC programming commands, or the relationship can be defined through CfgMotOffsetAng.

Using the Encoder Feedback Configuration tool can quickly optimize RDP alignment. CfgFbkRDGain defines the peak amplitude of the reference sine wave, while CfgFbkRDcosPhase defines the phase delay of the Cosine phase of the biphasic oscillator, mainly used for Inductosyn, and can also compensate for large phase lag caused by rotation. When using Cosine phase adjustment, the JP1 or JP2 of the channel should be set to 2-3, and the corresponding bit of CfgFbkRDConfig should be set to 1. There are two ways to initialize the commutation of brushless motor rotary feedback: R/D automatic configuration or Hall effect initialization. R/D automatic configuration is usually not suitable for Inductosyn because it has multiple electrical cycles per revolution. In dual loop mode, the position source generates commutation initialization, while the velocity source maintains commutation position after enabling.

Motor wiring and phase adjustment

When wiring brushless motors, motor A/B/C must correspond correctly with Hall A/B/C. 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. Hall signal connected to J207: Hall A pin 10, Hall B pin 5, Hall C pin 11. You can observe the Hall status on the Nstat diagnostic page and determine the phase based on it. In terms of encoder phase, the forward motion command should increase the encoder count. If the count decreases, Sin and Sin-N can be exchanged, or CfgFbkTelMultiplier and CfgFbkPosMultiplier can be inverted. When configuring the dual loop, only the feedback parameter of the wrong reverse connection is taken.

When the brushed motor is in torque mode, the positive command should cause the motor to rotate clockwise, corrected by swapping the A/C motor wires. When equipped with a speed measuring machine feedback, the speed measuring machine can be connected to TB302 or J205, using analog input 0. The voltage of the speedometer should not exceed ± 10 V, otherwise the speed loop may be unstable and cause runaway. If necessary, add a resistor voltage divider network and a 1 µ F capacitor filter. The forward command of the stepper motor is clockwise. If it is the opposite, switch the 0A and 0B terminals. The limit switch includes CW, CCW, and Home, connected to J207 pins 12, 24, and 22. You can also use J205 input 8-10 to configure limit settings through DriveIOConfig bit22. ESTOP requires an external fail safe emergency stop circuit for TB201 input, with an input voltage 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 emergency stop faults.

Voltage current mode and independent operation

Firmware 2.06 and above supports voltage current mode. This mode allows NDrive HL to function as an independent current controller, receiving ± 10 V torque commands from external position/speed controllers, without the need for real-time FireWire connection, but parameter configuration still requires A3200 software. Pay attention to current loop parameters, feedback configuration, commutation information, and current limits during configuration. After parameter verification, execute FLASHWRITE 1 0 0 through NDebug to save to flash memory, then power off, set DIP switches 6 and 7 to OFF, and power on again to enter voltage current mode.

In this mode, analog input 0 is used as the current/torque command, with+10 V corresponding to negative peak current and -10 V corresponding to positive peak current. Input 8 is used as the enable and output 8 is used as the fault output, both of which are of fail safe polarity. The fault may come from driver overcurrent, motor RMS overcurrent, motor thermistor overheating, amplifier temperature fault, or bus power failure. For the application of replacing old centralized control systems, this mode can extend the service life of NDrive HL on non A3200 platforms.