Product Description:

The 3DI476.6 digital input module is manufactured by B&R Automation for the System 2005 Controllers series. Installed on a base or expansion unit, it occupies one slot in the backplane and converts field contact closures into logic-level signals that the CPU can process. Within an automated cell, this module accepts status information from limit switches, light curtains, or operator push-buttons so the controller can start, stop, or interlock machinery according to programmed conditions.

This card offers 16 discrete input channels arranged as four groups of four, a layout that lets field devices be wired by machine section while keeping commons separated. Each channel supports a Sink/Source circuit, permitting either PNP or NPN field devices on the same board. The electronics use a nominal control voltage of 24 VDC and will tolerate up to 30 VDC without functional error. Propagation through the opto-isolator never exceeds 1.2 ms, so the PLC can react quickly to guard door openings or conveyor photo-eye changes. Low and high switching thresholds are set at 5 V and 15 V to prevent chatter in noisy environments. Isolation is provided between the PLC backplane and each group, while channels inside the same group share a common return.

The front panel carries 16 diagnostic LEDs that mirror input states, and each channel loads the sensor circuit with an impedance of 4.8 kΩ. The module withstands transient events up to 500 V for 50 µs every 100 ms without damage, protecting upstream switch contacts. An IP20 housing safeguards the electronics when the unit is enclosed in a control cabinet, while total dissipation remains below 1.5 W, minimizing the cabinet's thermal load. The module mounts by simple engagement of its rear connector and front locking tabs, eliminating the need for additional wiring harnesses.