OMRON C500-NC103-E Position Control Unit

The OMRON C500-NC103-E is a dedicated position control unit designed for the C500 series programmable logic controllers. This intelligent module provides open‑loop pulse train outputs to drive stepper motors or servo drives that accept pulse‑direction inputs, enabling precise point‑to‑point positioning and speed control. It is particularly suited for applications such as conveyor indexing, positioning tables, and simple CNC axes where cost‑effectiveness and reliability are paramount.

The NC103‑E operates as a slave module on the C500 backplane, receiving positioning commands and parameters from the CPU. It features two independent axes of control, each capable of generating up to 100 kpps (kilo‑pulses per second) with programmable acceleration and deceleration profiles. The module includes built‑in limit switch inputs and an emergency stop input for safe operation. Its compact design occupies a single slot in the C500 rack, preserving space for other I/O modules.

Technical Specifications

• Number of axes: 2 (independent, open‑loop pulse output)

• Pulse output frequency: 1‑100 kpps (software selectable)

• Position command range: -8,388,607 to +8,388,607 pulses

• Acceleration/Deceleration: Programmable (S‑curve or trapezoidal)

• Inputs per axis: 2 x limit switches (CW/CCW), 1 x emergency stop

• Outputs per axis: Pulse (CW/CCW or pulse‑direction), and servo‑on enable

• Data transfer: D‑sub 25‑pin connector (for each axis)

• Memory allocation: 8 I/O words (control and status), 4 data words (position data)

• Power consumption: 5 V DC, 200 mA (from backplane)

• Operating temperature: 0°C to +55°C

• Dimensions: Standard C500 module (single slot)

Functional Features

• Independent axis control: Each axis can operate independently with its own set of parameters, allowing coordinated movement or individual positioning tasks.

• Relative and absolute positioning: Both incremental (relative) and absolute position commands are supported via the PLC program.

• Speed override: The pulse output frequency can be adjusted on the fly, enabling manual jogging or adaptive speed control.

• Diagnostic feedback: Status flags indicate completion, error conditions (overrun, limit switch activation), and busy states.

Typical Applications

• Indexing tables: Precise rotation of turntables for assembly operations.

• Linear actuators: Positioning of pick‑and‑place heads and slide mechanisms.

• Packaging equipment: Controlling film feed and cut‑to‑length systems.

• Testing machinery: Positioning test probes over components.

Integration with C500 PLC

The C500‑NC103‑E plugs directly into the C500 backplane and is automatically recognized by the CPU. Programming is performed using the OMRON SYSMAC support software (or earlier programming tools). The user sets the positioning data and control bits in the allocated I/O memory area. For each axis, the CPU writes the target position (pulse count) and issues a start command; the module then independently manages the acceleration, constant speed, and deceleration profile. Completion and error flags are read back to confirm operation. The module also supports a “stop” command for immediate or controlled deceleration.

Wiring and Cabling

Each axis connects via a standard D‑sub 25‑pin connector. The pulse output lines (pulse and direction) should be wired to the driver using shielded twisted‑pair cables to minimize electromagnetic interference. The limit switch inputs require 24 V DC signals (sourcing or sinking, depending on connection). The emergency stop input must be a normally closed contact, which disables the pulse output when opened. All wiring should be kept away from high‑voltage cables to preserve signal integrity.

Environmental and Compliance

This module complies with EN 61131‑2 and carries CE marking. It is RoHS compliant and rated for operation in pollution degree 2 environments.

Conclusion

The OMRON C500‑NC103‑E position control unit offers a cost‑effective, reliable solution for integrating basic motion control into C500‑based PLC systems. Its two‑axis capability, programmable profiles, and simple integration make it an ideal choice for a wide range of indexing and positioning applications.