Application Scenarios
Consider an older manufacturing facility where a PLC-5 processor in the main control room supervises a series of 1771 I/O chassis distributed along a production line. Each chassis needs to report dozens of discrete inputs and accept outputs, but running individual field wires back to the control room would be prohibitively expensive. The 1771-KX1 solves this by placing the communication intelligence at the chassis: one twisted-pair link carries the complete I/O image back to the scanner, and the processor sees every point in the remote frame as if it were wired locally.
The value becomes clear during troubleshooting. When a remote chassis stops communicating, the maintenance team does not have to test dozens of field wires individually — they diagnose the link at the adapter, confirm the chassis status, and isolate the fault to a communication issue or a genuine I/O problem. On a running line, that distinction saves hours. For plants still operating PLC-5 and 1771 equipment, the 1771-KX1 is the component that keeps distributed I/O reachable, and it is why these modules remain in demand long after their discontinuation.
Parameter
| Main Parameters | Value/Description |
|---|---|
| Product Model | 1771-KX1 — communication adapter module for 1771 I/O chassis |
| Manufacturer | Allen-Bradley, Rockwell Automation (USA) |
| Product Category | Communication adapter / remote I/O interface module |
| Chassis Compatibility | 1771 I/O chassis (8-, 12-, or 16-slot frames) |
| Slot Position | Dedicated communication slot — placement follows the specific chassis wiring convention |
| Communication Link | Remote I/O serial link over 1771-KG / 1771-CG twisted-pair cable |
| Transmission Rate | 57,600 bps remote I/O link rate |
| Network Topology | Trunk-and-drop; supports multiple adapters on a single scanner link |
| I/O Image Handling | Full chassis scan: inputs read, outputs written, and status returned each scan cycle |
| Error Checking | Built-in error detection and retry on the remote I/O link |
| Indicators | Module status, communication activity, and fault LEDs |
| Addressing | Configured by chassis DIP switches or module jumpers, depending on chassis variant |
| Cable Interface | Screw-terminal connections for 1771-KG / 1771-CG cable pair |
| Mounting | Mounts in the designated communication slot of a 1771 I/O chassis |
| Enclosure / Protection | Open-style module; chassis must be installed in an industrial enclosure |
| Operating Temperature | 0…60 °C, non-condensing; storage −40…+85 °C |
| Certifications | UL, cUL, CE, RoHS compliant (legacy approvals current at time of manufacture) |
| Lifecycle Status | Discontinued — available as new-surplus and refurbished stock |
