A linear axis can move during a bench test and still be incorrectly commissioned. Wrong travel scaling, reversed feedback, excessive following error, or poorly placed limits may remain hidden until the first production move. A disciplined startup proves each layer before tuning adds speed.

This workflow applies to servo and closed-loop stepper systems. Product menus differ, but the engineering sequence is consistent: inspect mechanics, define the machine model, verify safety, establish direction, prove limits, home, and only then optimize control response.

Start With Mechanics and Energy

Lock out energy before checking the screw, belt, carriage, couplings, lubrication, and hard stops. The carriage should move through the intended stroke without binding. A tight spot can look like a tuning problem after power is applied.

Record the screw lead or belt travel per motor revolution. Include gearbox ratio and any external encoder ratio. Do not estimate travel from a single hand mark when drawings or measured multi-turn travel are available. Measuring over several revolutions reduces error.

The drive is only one part of the axis model; motor, feedback, transmission, load, and travel limits must agree.

Confirm the Drive, Motor, and Feedback

Verify supply voltage, motor current, encoder type, brake wiring, and drive firmware compatibility. The Festo CMMT-ST family, for example, uses a 24–48 V DC primary supply and can operate stepper or brushless DC motors. Its exact motor and feedback configuration still depends on the selected variant.

Enter motor data from the approved data set when the software provides one. Manual values should come from current manufacturer documentation. A wrong current limit can overheat a motor, while incorrect feedback resolution corrupts position scaling.

A direct-drive ball screw removes a gearbox, but screw lead, coupling stiffness, and end support still shape the motion response.

The store's drives and motion control collection provides a related path for compatible drive hardware. Selection must still be based on torque, speed, inertia, voltage, and feedback requirements.

Treat STO as a Safety Function

Safe Torque Off removes torque-producing energy from the motor, but it does not isolate incoming power and does not apply a mechanical brake. A vertical or overhauling load may move after STO. The machine risk assessment determines whether STO alone is sufficient.

Wire and validate the safety circuit according to the drive manual and the machine safety design. Do not use a temporary jumper as the final commissioning method. Confirm the stop button, reset behavior, diagnostic coverage, and restart interlock before powered motion.

Build the Axis Model

Configure travel per motor revolution, gear ratio, encoder resolution, maximum velocity, acceleration, deceleration, and jerk. Set software limits inside the physical stroke. Leave enough stopping distance for the worst permitted speed and load.

Device identity and protocol selection should match the installed drive, firmware, and controller project.

For networked axes, confirm the selected EtherNet/IP, PROFINET, EtherCAT, or Modbus TCP profile. A device may support several protocols, but the active profile determines cyclic data, state handling, and diagnostics.

Prove Direction Before Position

With the axis unloaded or at low risk, rotate the mechanism by hand if permitted. Confirm that positive mechanical travel creates increasing actual position. If feedback and commanded direction disagree, correct the configured direction or wiring as the manufacturer specifies.

Connect to the intended drive and verify its address before downloading parameters.

Enable motion at a low current limit, low velocity, and short travel distance. Jog away from the nearest hard stop first. Watch commanded position, actual position, following error, current, and limit inputs together.

Validate Limits and Homing

Test each hardware limit input at low speed before relying on it. Confirm the controller reports the correct end and inhibits motion farther into that limit while allowing recovery in the safe direction.

Choose a homing method that creates a repeatable machine reference. A home switch alone may vary with approach speed and hysteresis. Many systems improve repeatability by combining a switch edge with an encoder index. Absolute encoders change the startup strategy but still require a validated machine datum.

Motor data, mechanical scaling, and travel limits should be reviewed together before the first powered move.

Tune From Evidence

Auto-tuning can establish useful starting gains, including on third-party mechanics, but it cannot repair backlash, misalignment, looseness, or insufficient stiffness. Capture plots of command, actual position, following error, velocity, and current.

Increase speed and acceleration in steps. Stop when current margin, settling time, vibration, temperature, or mechanical load approaches the design limit. A quiet axis at low speed is not proof of stable behavior across the operating envelope.

Coordinate axis states and fault recovery with the PLC and PAC systems collection when the motion controller is integrated into a wider machine sequence.

Engineering View

Good commissioning makes faults visible. It separates mechanical drag from control instability and distinguishes wrong scaling from poor tuning. The best result is not the highest gain value. It is an axis with documented limits, repeatable homing, predictable stops, and trend data that maintenance teams can use.