Compatibility
Allen-Bradley ControlLogix and CompactLogix driver for SCADA
Nexus, the Raylux gateway, talks to ControlLogix and CompactLogix controllers over EtherNet/IP with the ab-eip driver. It is included in every licence.
What it connects to
The ab-eip driver speaks Allen-Bradley over EtherNet/IP. The manual names ControlLogix and CompactLogix 5370 and later. The compatibility checker also treats the 5380 and 5480 generations as native.
EtherNet/IP carries CIP, the protocol Rockwell controllers use, over standard Ethernet. Nexus connects to the controller’s address and reaches the processor along a CIP route.
Setup in brief
A device entry sets four things. driver is ab-eip, gateway is the controller’s IP address, path is the CIP route to the processor, and plcType is the family, for example ControlLogix. A slot-0 processor in a single-rack chassis is commonly 1,0. slot is accepted as the simpler form of the same idea.
Then bind tags to the device in Studio. Like every Nexus device, it carries a name, an endpoint, a port, a fallback pollRateMs, a timeoutMs and a reconnectDelayMs. The name is what tags refer to, so rename a device in the configuration interface rather than by hand in the file, or its tag bindings break. A device holds no address list. It polls exactly the tags bound to it, so adding a tag in Studio starts it scanning without editing the device or restarting Nexus.
The settings are in the manual under Devices and drivers, Allen-Bradley. That page lists the connection settings. Confirm the tags you plan to read against your own controller on the trial.
Scan rates and dropped links
Scan rate comes from the tag group, not the device. A group is direct (a fixed rate), leased (quick while something is watching the tag, slow otherwise) or driven (quick while an expression is true). A fresh gateway ships with default-fast at 250 ms, default-slow at 5000 ms and default-historical at 10 s. A tag goes Stale after its rate times staleMultiplier passes without an update, and returns to Good once it is being read again. A rate faster than the device can answer does not bring data sooner; the poll just falls behind.
A device that stops answering is marked disconnected, and its tags follow the quality rules instead of freezing at their last value. Writes forwarded to a device that has since dropped are not silently discarded. The device list in the Nexus configuration section shows each device’s state, with the reason for a failure in the tooltip. The troubleshooting page covers the usual causes.
Limits
The ab-eip driver covers ControlLogix and CompactLogix 5370 and later. MicroLogix, SLC 500, PLC-5, Micro800 and CompactLogix older than 5370 (1769-L32E, L35E and the 1768) are outside that range. If one of those offers Modbus TCP or an OPC UA route, Nexus can read it that way.
Licence and trial
Every driver is included in the base licence, which lists at $995. No driver is sold separately, and there is no per-protocol or per-gateway driver charge.
The free trial runs for two hours with every driver unlocked, and you can restart it as often as you like. Point it at the controller on your bench and read a tag before you decide anything.
Related drivers
Next step
Read a tag off your own PLC.
The trial is two hours with every driver unlocked, and restartable as often as you like. Point it at the controller on your bench before you decide anything.