1756-IA16I | Allen-Bradley Isolated Input Module

The 1756-IA16I is a 16-point AC digital input module from the Allen-Bradley ControlLogix platform. It is designed to receive AC signals in the range of 79–132V AC, with a nominal voltage of 120V AC. Each input channel is individually isolated, which helps prevent signal interference and enhances system safety. This isolation feature makes it ideal for applications involving multiple voltage domains or electrically noisy environments. The module is widely used in machine control, process automation, and energy systems. It connects to the ControlLogix backplane and integrates seamlessly with Logix controllers.

Yes, the 1756-IA16I supports hot-swapping, which means it can be inserted or removed from a powered ControlLogix chassis without shutting down the system. This feature significantly reduces downtime during maintenance or replacement. However, for safety, it's important that no field voltage is present at the terminal block during hot-swap operations. The use of removable terminal blocks (1756-TBCH or 1756-TBS6H) enables tool-free removal and reinsertion. Hot-swapping is especially useful in high-availability applications where minimal interruption is critical. Always follow manufacturer procedures to avoid accidental damage or unsafe conditions

The module is compatible with the 1756-TBCH and 1756-TBS6H removable terminal blocks (RTBs). These RTBs allow field wiring to remain intact while replacing the module, significantly reducing downtime. The RTB securely connects to the front of the module, enabling quick, tool-free installation. Each block provides wiring points for the 36-pin input interface. RTBs are keyed to prevent incorrect installation. Their use improves safety, ease of maintenance, and long-term reliability.

Yes, every input channel on the 1756-IA16I is individually isolated from the others. This means each channel has its own optical or transformer-based isolation circuit, providing electrical separation between inputs. This feature prevents ground loops and electrical interference across different input points. It is especially important when inputs come from devices operating on different power supplies or potential references. Individual isolation enhances system diagnostics, safety, and long-term reliability. It is one of the key advantages of the “IA16I” over the non-isolated variants.

Yes, the 1756-IA16I remains an active product in the Allen-Bradley ControlLogix catalog. It is currently supported and widely available through Rockwell Automation and authorized distributors. The module continues to be used in both legacy and new industrial automation systems due to its reliability and standard voltage range compatibility. As part of the ControlLogix family, it benefits from long-term product lifecycle support. Users can consult the Rockwell Product Lifecycle Status tool for real-time updates. Its continued production ensures availability of spares and replacements for the foreseeable future.