OMRON CK3W-AX Multi axis Control Selection

EQU: Equal position output (conducts when the actual position is within tolerance of the instruction position)

All these signals are optically isolated and require an external 24V power supply for wiring. The polarity depends on the unit model (NPN or PNP).

5.2 Universal digital I/O (via 50 pin terminal block)

Each unit provides 16 inputs/16 outputs, independent of the axis function. These I/O can be used to control peripheral devices (cylinders, sensors, indicator lights, etc.) and read and write directly through variables of Power PMAC. Typical applications: fixture control, material detection, alarm display.

Input circuit: NPN/PNP compatible (depending on the unit), response time ≤ 1 ms.

Output circuit: transistor output, maximum 50 mA per point, with short-circuit protection.

Key points for debugging and troubleshooting

6.1 Pre power on inspection

Power wiring: Confirm that the CPU rack and expansion rack are powered by the same 24V power supply, and the grounding resistance is ≤ 100 Ω.

Unit address: The address switches of all CK3W-AX units are set correctly and without conflicts.

Cable connection: Insert the encoder cable and amplifier cable tightly, and tighten the screws.

Terminal resistor: For differential numerical control signals (such as encoders A/B), check if the terminal resistor is correctly connected at the end of the cable (if the driver is built-in, it can be skipped).

I/O polarity: Confirm that the external wiring of the universal I/O matches the unit type (NPN external 0V common terminal, PNP external 24V common terminal).

6.2 Common Problems and Countermeasures

Possible causes and solutions for the phenomenon

The Amp Enable indicator light is not on. The servo drive is not ready or the fault input signal is abnormal. Check if the Fault input is low level (usually ON when normal) and check the driver alarm output

The motor does not rotate, there is no alarm, the simulated command voltage is 0, or the PWM output is disabled. Check the Motor [x]. Ctrl and motor enable positions in the Power PMAC

Encoder feedback abnormality (position jump), poor shielding of encoder cable, or reverse connection of differential signal line. Use an oscilloscope to check the A+/- signal and ensure that the shielding layer is grounded at a single point

Unit status register error (CK3WConfigErr=5) Extended main unit not adjacent to CPU unit, rearranging rack unit order to the right

Multiple units cannot be recognized due to address switch conflicts or insufficient rack power. Check the address settings and calculate the total power consumption (5V/24V)

6.3 Debugging with Power PMAC IDE

After establishing the project, set the encoder count mode and output mode for each axis on the Gate3 configuration page.

For the True DAC type (AX1515), the range of DACA and DACB can be configured separately (± 10V or ± 20V).

Utilize online monitoring function to view encoder count values, instruction tracking errors, limit status, etc. in real time.

If a sine encoder is required, SIN/COS interpolation multiplication (e.g. x4096) must be enabled in the encoder parameters to achieve high resolution.

Practical application cases and wiring suggestions

Case: 4-axis high-speed picking and placing robot

Install two CK3W-AX1414N units using a CK5M CPU and an expansion rack.

Each AX1414N controls two servo motors (4 axes in total), both using ± 10V analog commands.

The encoder uses a digital orthogonal type (10000 lines/rev) and is connected through CK3W-CAED03A cable.

Universal I/O is used to control vacuum suction cups and cylinders.

Wiring precautions:

Lay the encoder cable and power cable separately, with a spacing of ≥ 200mm.

All shielding layers are grounded on the controller side to avoid multiple grounding points forming a ground loop.

Use ferrite magnetic rings to cover the input power line of the servo driver to suppress high-frequency interference.