RSLinx Classic Setup and Driver Configuration for Allen-Bradley PLCs

Quick Answer

RSLinx Classic is Rockwell Automation's communication server that manages the connection between a PC and Allen-Bradley controllers. It provides the communication path used by Studio 5000, RSLogix, FactoryTalk View, and OPC-based SCADA systems. Configure an Ethernet or serial driver and use RSWho to browse and verify device connectivity.

What Is RSLinx Classic?

RSLinx Classic runs as a Windows service and acts as a communication middleware between software applications and Allen-Bradley hardware. It manages driver instances for different physical networks (Ethernet, serial, USB) and presents a unified network view via the RSWho browser. Third-party SCADA systems can use RSLinx as an OPC DA server to access Allen-Bradley PLC data.

RSLinx Classic vs RSLinx Enterprise vs FactoryTalk Linx

• RSLinx Classic — The traditional communication server. Used for Studio 5000, RSLogix, and OPC DA connections.
• RSLinx Enterprise — Designed for FactoryTalk View SE server environments. Supports OPC UA.
• FactoryTalk Linx — The modern replacement for RSLinx. Integrated with Studio 5000 v32+ and supports OPC UA. Recommended for new installations.

Installing RSLinx Classic

RSLinx Classic is included in the Rockwell Automation installation media or can be downloaded separately. The installation includes the RSLinx Classic service, RSWho network browser, and OPC server components. A license is required for OPC server functionality; the RSLinx Classic Lite version (free) supports programming connections only.

Configuring an EtherNet/IP Driver

1. Open RSLinx Classic and go to Communications > Configure Drivers.
2. Select EtherNet/IP Driver (AB_ETH or AB-ETHIP-1).
3. Click Add New and name the driver.
4. In the driver configuration, select the network adapter and subnet to scan.
5. Click OK. The driver will scan the subnet and discover Allen-Bradley devices.

Configuring a Serial DF1 Driver

For serial connections to MicroLogix or SLC 500 controllers, configure the RS-232 DF1 driver with the correct COM port, baud rate (typically 19200), and DF1 settings (point-to-point for direct connection, multi-drop for networked serial).

Configuring a USB Driver

Connect a USB cable from the PC to the controller's USB port. RSLinx automatically detects the connection and creates a USB driver instance. This is the simplest connection method for direct programming.

RSWho — Browsing the Network

RSWho is the network browser built into RSLinx. It displays a hierarchical view of all discovered devices organized by driver and network. Use RSWho to:

• Verify that a controller is visible on the network
• Check device IP addresses and firmware versions
• Identify the communication path for Studio 5000 connections

RSLinx as OPC Server for Third-Party SCADA

RSLinx Classic includes an OPC DA server that third-party SCADA platforms can use to access Allen-Bradley PLC data. Configure OPC topic mappings in RSLinx and connect from the SCADA platform using the OPC DA server name. Note that Ignition connects directly to Allen-Bradley PLCs using its native EtherNet/IP driver without requiring RSLinx. Geo SCADA can use OPC DA through RSLinx or connect via alternative protocols.

Troubleshooting

• Device not appearing in RSWho — Verify the driver is configured on the correct network adapter. Check cable connections and IP addressing. Ensure the Windows Firewall allows RSLinx traffic.
• Driver errors — Reinstall the driver. Check for IP conflicts. Verify the network adapter is enabled.
• Path issues in Studio 5000 — Use RSWho to identify the correct communication path, then enter it manually in the Studio 5000 Who Active dialog.