How to Connect Motion Controllers in RTSys: Ethernet, Serial & Local

Establishing a reliable connection between your PC and the motion controller is the first critical step in any automation project. Whether you are setting up a new machine or troubleshooting an existing system, understanding the available communication methods can save hours of downtime. RTSys, a versatile programming software for motion control, supports three primary connection types: Ethernet (TCP/IP), Serial (RS-232/RS-485), and PCI/Local. Each method has its own advantages, and the choice depends on your controller model, required speed, and application environment.

Before diving into the connection procedures, ensure that the controller is powered on and the appropriate communication cable (Ethernet, serial, or PCIe) is securely connected to the host PC. For controllers equipped with a real-time kernel like MotionRT, a Local connection offers ultra-low latency, making it ideal for high-speed applications such as laser cutting or precision assembly.

Connection Methods Overview

In RTSys, navigate to “Controller” → “Connect” → “Controller” to open the connection dialog. The window presents three tabs: Serial, IP, and PCI/Local. The table below summarizes the key parameters for each method.

Ethernet Connection – Step by Step

Ethernet is the recommended method for most applications due to its speed, convenience, and ability to handle multiple controllers on the same network. The controller’s default IP address is typically 192.168.0.11. For models with dual Ethernet ports (e.g., VPLC5 series), LAN1 defaults to 192.168.0.11 and LAN2 to 192.168.1.11.

To establish a connection, your PC must be on the same subnet. That means the first three octets of the IP address must match, and the fourth must be unique. For example, if the controller is 192.168.0.11, set your PC to 192.168.0.100 with subnet mask 255.255.255.0.

Changing the Controller IP Address

If you need to modify the controller’s IP (e.g., to integrate into an existing plant network), you must first establish a connection – either via Ethernet (if you know the current IP) or via serial as a fallback. Once connected, use one of these methods:

Note: Both LAN ports must be on different subnets. After changing the IP, the connection drops automatically.

Verifying the IP Address

To check the current IP address of a connected controller:

• Navigate to “Controller” → “Controller Status” – the IP is displayed in the status window.
• Use the online command PRINT IP_ADDRESS. The output is a decimal number; convert it to dotted-decimal format (e.g., 3232235531 becomes 192.168.0.11).

Serial Connection – Reliable Fallback

Serial communication remains a dependable option, especially for initial configuration or when Ethernet is unavailable. The controller’s default serial parameters are baud rate 38400, 8 data bits, 1 stop bit, no parity. Ensure your PC’s COM port settings match exactly.

In RTSys, select the correct COM port from the dropdown (it auto-populates available ports). If using a USB-to-serial adapter, a virtual COM port will appear; verify its number in Windows Device Manager under “Ports (COM & LPT)”. Click “Connect” and watch the output window for a success message.

PCI and Local Connections – High-Speed Real-Time

For PCI or PCI Express motion control cards installed directly in an industrial PC, the PCI connection scans the bus for the card number. Before using this method, install the driver according to the card’s user manual. Once the card is recognized, select its number in the RTSys connection dialog.

The Local connection leverages the MotionRT real-time kernel, which runs on the same PC as RTSys. This setup is typical for XPCI/XPCIE series cards. After installing the MotionRT driver and launching the MotionRT configuration tool, start the kernel. RTSys will then list available MotionRT instances in the Local tab. Select the one corresponding to your card and connect. This method achieves deterministic microsecond-level response, essential for applications like electronic gearing or high-speed registration.

Best practice: When using a motion control card, always prefer the Local connection over PCI for lower latency and better real-time performance.

Confirming a Successful Connection

Regardless of the connection method, RTSys provides immediate feedback. After clicking connect, check the “Command & Output” window at the bottom of the software. A successful connection prints the controller model and firmware version without error messages. If you see timeout errors or “connection failed,” revisit the settings and physical wiring.

For advanced diagnostics, use the online command ?*IDN or similar queries to verify communication integrity.

Key Takeaways for Reliable Controller Communication

• Always match IP subnets or use a wider subnet mask when connecting to a controller with an unknown IP.
• Keep a serial cable handy as a backup for IP recovery or firmware updates.
• For real-time applications, invest in MotionRT-compatible hardware and use Local connection.
• Regularly check for software updates and driver compatibility to avoid connection issues after OS patches.

Mastering these connection techniques ensures smooth commissioning and minimizes downtime in your automation projects. Whether you’re integrating a simple electrical control panel or a complex multi-axis system, a solid communication foundation is non-negotiable.