OMRON CK3W-AX Multi axis Control Selection

OMRON CK3W-AX Axis Interface Unit: Complete Guide to Multi Axis Motion Control System Design and Wiring

In the field of modern precision motion control, multi axis synchronous control, high-speed encoder feedback, and flexible driver interfaces are the core of equipment performance. OMRON's CK3W-AX series axis interface unit, as an important component of the CK3M/CK5M series programmable multi axis controllers, provides engineers with a highly integrated and scalable axis control solution. A single CK3W-AX unit can control up to 4 axes, support analog command servo drivers and DirectPWM servo drivers, and can connect multiple types of position feedback encoders. This article will systematically analyze the model selection, system configuration, dedicated cable wiring, signal definition, and debugging points of CK3W-AX unit from the perspective of engineering practice, to help engineers quickly build a reliable multi axis motion control system.

Product Overview and Core Features

The CK3W-AX unit is a shaft interface module designed specifically for the CK3M/CK5M series motion controllers. It is located in the CPU rack or expansion rack and communicates with the CPU unit through unit side connectors. Each unit can handle up to 4 servo axes.

Core features:

Multi axis capability: 4 channels per unit, suitable for independent devices with less than 4 axes, or extended to more axes through multi unit cascading.

Flexible driver interface:

Analog output type: Supports filtered PWM or true DAC output, suitable for traditional ± 10V analog command servo drivers.

DirectPWM type: Directly outputs PWM pulse signals, which can be combined with intelligent servo drivers (such as CK3A-G3L) that support PWM interfaces to achieve higher bandwidth current loop control.

Rich encoder interfaces:

Digital Orthogonal Encoder (A/B/Z Differential Signal)

Serial encoder (contact OMRON to confirm specific protocol)

Sine encoder (1 Vpp SIN/COS)

Hall sensor (U/V/W/T signal)

Built in I/O: Each unit comes with 16 point digital input and 16 point digital output (NPN or PNP type), as well as dedicated flag inputs (HOME, positive limit, negative limit, user input) and an EQU output for each axis.

These characteristics make the CK3W-AX unit particularly suitable for applications that require high real-time and precision, such as high-speed surface mount machines, semiconductor equipment, laser processing, and precision inspection.

Model Classification and Selection Guide

CK3W-AX is divided into multiple sub models based on the type of output circuit and encoder interface. The correct selection is the first step in system design. The following table summarizes the main models and their key differences:

Model Output Type Encoder Interface Universal I/O Polarity Description

CK3W-AX1313N DirectPWM Digital Orthogonal/Serial NPN Low cost, High speed PWM Output

CK3W-AX1313P DirectPWM Digital Orthogonal/Serial PNP Same as above, PNP Type I/O

CK3W-AX1414N filtered PWM digital orthogonal/serial NPN analog instruction output, 1 point/channel

CK3W-AX1414P Filtered PWM Digital Orthogonal/Serial PNP Same as above, PNP Type I/O

CK3W-AX1515N True DAC Digital Orthogonal/Serial NPN True ± 10V Analog Output, 2 Points/Channel

CK3W-AX1515P True DAC Digital Orthogonal/Serial PNP Same as above, PNP Type I/O

CK3W-AX2323N DirectPWM sine/serial NPN supports 1 Vpp sine encoder

CK3W-AX2323P DirectPWM sine/serial PNP as above, PNP type I/O

2.1 Selection of Output Types

DirectPWM (AX1313/AX2323): Output as differential line drive pulses (PULSE+DIR or phase difference form), with a maximum frequency of 10 MHz. Suitable for intelligent servo drives that accept PWM control signals, such as OMRON CK3A-G3L. Due to the elimination of D/A conversion, the delay is lower, making it suitable for high dynamic response applications.

Filtered PWM (AX1414): The output is a low-pass filtered PWM signal, with each channel providing a differential analog output pair (DACA+/-). Output range ± 20 V (± 10 V to ground), suitable for traditional ± 10V command servo.

True DAC (AX1515): Each channel provides two independent analog outputs (DACA+/- and DACB+/-), which is a true bipolar digital to analog conversion with higher accuracy and linearity. Suitable for advanced applications that require simultaneous output of speed/torque commands or dual closed-loop control.

2.2 Selection of Encoder Interface

Digital Orthogonal Encoder: Supports A/B/Z differential signals (RS-422), with a maximum response frequency of 10 MHz. Combined with CK3W-CAED03A dedicated cable, it can be connected to incremental grating rulers or rotary encoders.

Sine encoder (1 Vpp): Supports SIN/COS differential signals and is suitable for high-resolution sine and cosine encoders (such as some models of Heidenhain). CK3W-CAEA03A cable is required, and an INDEX pulse is provided.

Serial encoder: Supports multiple serial protocols (specific protocols need to be consulted with OMRON). Can connect absolute encoders such as BISS and EnDat, using CK3W-CAES03A cable.

Hybrid interface: Some cables support simultaneous transmission of digital orthogonal signals and UVW Hall signals, or simultaneous transmission of sine signals and serial data, making it easy to integrate brushless motors with commutation sensors.