EtherNet/IP Explorer for macOS: Connect to Allen-Bradley PLCs Without RSLinx
You need to read a tag from an Allen-Bradley ControlLogix PLC. Maybe verify a temperature reading, check a motor run status, or write a setpoint to a controller. The standard workflow is: open RSLinx, browse the PLC, find the tag, read the value. RSLinx only runs on Windows. FactoryTalk View? Windows. RSLogix/Studio 5000? Windows.
Allen-Bradley PLCs (ControlLogix, CompactLogix, MicroLogix) are ubiquitous in North American manufacturing. If you work with industrial automation in the US or Canada, you deal with Allen-Bradley. And if you use a Mac, you have been running Parallels or a Windows VM just to interact with these PLCs. For a broader look at how EtherNet/IP compares to other industrial protocols, see our industrial protocol comparison guide.
The Allen-Bradley Tool Chain Problem
Rockwell Automation's software ecosystem is deeply Windows-bound:
- RSLinx — The OPC server and communication driver for Allen-Bradley PLCs. Windows-only, requires FactoryTalk activation licensing.
- FactoryTalk View — HMI and SCADA development environment. Windows-only, expensive.
- Studio 5000 / RSLogix 5000 — PLC programming software. Windows-only, expensive.
- KEPServerEX / Kepware — Third-party OPC server that supports Allen-Bradley. Windows-only, licensed per driver.
What EtherNet/IP Communication Requires
To interact with an Allen-Bradley PLC over EtherNet/IP, you need:
- Device discovery. Find ControlLogix and CompactLogix PLCs on the network. Enumerate their backplanes, modules, and available tags.
- Tag browsing. Browse the controller's tag database — user-defined tags, system tags, and module tags. See tag names, data types (BOOL, DINT, REAL, STRING, arrays, UDTs), and current values.
- Read tags. Read values from any tag in the controller. Atomic types, arrays, and structured user-defined types.
- Write tags. Write values to writable tags — command outputs, setpoints, mode selections, recipe parameters.
- CIP message inspection. See the raw CIP request and response packets for debugging communication issues.
MacTools EtherNet/IP Explorer
MacTools EtherNet/IP Explorer implements the CIP protocol over EtherNet/IP directly in Rust. No RSLinx, no Kepware, no OPC server in between. Connect directly to the PLC from macOS. For integrating Allen-Bradley PLCs alongside Siemens S7 controllers in a unified monitoring system, see our guide to SCADA integration with Siemens S7 and Allen-Bradley.
PLC Discovery
Enter the PLC's IP address or use the built-in discovery to find Allen-Bradley devices on your subnet. The explorer queries the controller's identity object to show device type, revision, serial number, and status.
Tag Browser
Browse the full tag database of the controller. Tags are displayed with their names, data types, and current values. User-defined types (UDTs) are expanded to show member fields. Arrays show element counts. The tag browser mirrors the structure you would see in Studio 5000.
Read and Write
Read any tag by clicking it. Values are displayed according to their data type: booleans as TRUE/FALSE, integers as decimal, reals as floating point, strings as text. Write to any non-protected tag by entering the new value. The write uses the proper CIP data type formatting.
Structured Data Types
Allen-Bradley UDTs are decoded and displayed as nested structures. A motor control UDT shows its members: Speed, Current, Status, FaultCode. A PID UDT shows SP, PV, CV, and tuning parameters. Navigate structures without memorizing offsets.
Use Cases
Field Commissioning
When commissioning a new production line with ControlLogix PLCs, verify I/O wiring by reading input tags and confirming sensors respond. Write output tags to test actuators and valves. All from your MacBook, standing at the control panel.
Troubleshooting
Production is down. The operator says the conveyor stopped. Open MacTools, connect to the PLC, read the fault tags, check the motor status, verify the interlock conditions. Diagnose the problem without walking back to the engineering office to boot up Windows.
Integration Testing
Building a system that integrates with Allen-Bradley PLCs? Use MacTools to verify that your integration reads the correct tags and writes values that the PLC accepts. Test tag paths, data types, and array indices before deploying to production.
Try the EtherNet/IP Explorer
MacTools EtherNet/IP Explorer for macOS. Connect to ControlLogix and CompactLogix, browse tags, read and write values. No RSLinx, no Windows. $14.99 one-time.
Get MacTools EtherNet/IP ExplorerFrequently Asked Questions
Can I connect to Allen-Bradley PLCs from macOS?
Yes. Allen-Bradley ControlLogix, CompactLogix, and MicroLogix PLCs communicate using the CIP (Common Industrial Protocol) over EtherNet/IP, which is an open standard. You do not need RSLinx or Windows. A native macOS tool that implements the CIP protocol can connect directly to the PLC, browse its tag database, and read/write values.
What is CIP (Common Industrial Protocol)?
CIP is the application-layer protocol used by Allen-Bradley PLCs over EtherNet/IP. It handles device discovery, tag browsing, reading and writing controller tags, and diagnostic information. CIP is an open standard maintained by ODVA, so any tool that implements it can communicate with Allen-Bradley PLCs without proprietary drivers like RSLinx.
How do I read Allen-Bradley tags without RSLinx?
Use an EtherNet/IP explorer that implements the CIP protocol. Enter the PLC's IP address, connect, and browse the controller's tag database. You can read any tag by name, including atomic types (BOOL, DINT, REAL, STRING), arrays, and user-defined types (UDTs). Writes to non-protected tags work the same way by entering the new value.
Can I write to ControlLogix tags from macOS?
Yes. A CIP-based EtherNet/IP explorer on macOS can write values to any writable tag on a ControlLogix or CompactLogix controller. This includes setpoints, command outputs, mode selections, and recipe parameters. The write operation uses proper CIP data type formatting so the PLC accepts the value.
Need full SCADA monitoring?
If you need continuous monitoring, historical data, alarms, and dashboards across Allen-Bradley PLCs and other devices — not just a field tool — Voltrus SCADA includes native EtherNet/IP, Modbus, OPC-UA, and Siemens S7 support. Single binary, lifetime license from $249.