# Allen-Bradley Logix controllers

> Read and write Rockwell Automation Logix controllers by tag name, browse the tag list and use the data in OPC UA, SCADA and reports, without RSLinx.

PLCGateway connects ControlLogix, CompactLogix, GuardLogix and Micro800 controllers over EtherNet/IP with symbolic tag access. UDTs, arrays and strings are supported, and the tag browser shows the controller and program tags directly from the CPU.

Older PLC-5, SLC 500 and MicroLogix controllers can be brought in on Windows through RSLinx Classic and the OPC DA client. Together the whole Rockwell installed base can be published over OPC UA and MQTT.

## Families and models

| Family | Models (examples) | Protocol |
|---|---|---|
| ControlLogix | 1756-L7x (5570), 1756-L8x (5580), 1756-EN2T / EN4TR — Through the Ethernet module with a route path over the backplane, for example 1,0 for the CPU in slot 0. | [Allen-Bradley EtherNet/IP (CIP)](https://plcgateway.com/protocols/ethernet-ip.md) |
| CompactLogix | 1769-L3x (5370), 5069-L3xx (5380), 5069-L4xx (5480) — Directly through the built-in Ethernet port of the controller. | [Allen-Bradley EtherNet/IP (CIP)](https://plcgateway.com/protocols/ethernet-ip.md) |
| GuardLogix | 1756-L7xS, 1756-L8xS, 5069-L3xxS2 — Tags are read like other Logix tags; safety logic is not changed. | [Allen-Bradley EtherNet/IP (CIP)](https://plcgateway.com/protocols/ethernet-ip.md) |
| Micro800 | Micro820, Micro850, Micro870 — Directly, without a route path. | [Allen-Bradley EtherNet/IP (CIP)](https://plcgateway.com/protocols/ethernet-ip.md) |
| PLC-5 · SLC 500 · MicroLogix | RSLinx Classic OPC DA — On Windows through RSLinx Classic and the OPC DA client of PLCGateway. | [OPC DA client (OPC Classic)](https://plcgateway.com/protocols/opc-da.md) |

## Notes for commissioning

- Use the tag browser instead of typing names; UDT members are listed in the tree.
- Group many tags of one controller in one device: they are read with Multiple Service Packets.
- Writing to bits of integer tags uses read-modify-write.
- No Rockwell software or licence is needed on the PLCGateway computer for Logix controllers.

## Questions and answers

### Do I need FactoryTalk Linx or RSLinx?

Not for Logix controllers. Only PLC-5, SLC 500 and MicroLogix need RSLinx Classic as an OPC DA server.

### Can I browse the tags?

Yes, controller and program tags are listed from the controller; system tags are hidden.

### Are program-scoped tags supported?

Yes, with the syntax Program:Name.Tag.

## Related controllers and devices

- [Siemens SIMATIC](https://plcgateway.com/controllers/siemens.md)
- [Omron SYSMAC](https://plcgateway.com/controllers/omron.md)
- [Schneider Electric Modicon](https://plcgateway.com/controllers/schneider-electric.md)
- [All protocols](https://plcgateway.com/protocols.md)

_Product and model names are trademarks of their owners. They are named only to show which equipment the drivers communicate with; PLCGateway is not affiliated with these companies._

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Source: https://plcgateway.com/controllers/allen-bradley