Schneider B351 Input Module | 8 x 24V DC Digital Channels

The B351 reads digital input signals from field sensors and switches. This module transfers input status to the PLC processor for logic execution. Its rectangular frame measures 105 millimeters in width. The module height reaches 90 millimeters exactly. Depth stays at 75 millimeters. You will find this unit weighs approximately 0.38 kilograms. Therefore, installation requires a standard DIN rail clip mounted securely. One removable 12-position terminal block handles all field wiring connections.

Physical Layout and Connectors

The terminal block accepts wires up to 16 AWG gauge. Each channel uses two terminals for signal and return paths. A green LED indicates power present on the module. Individual red LEDs show status for each input channel. Four mounting tabs secure the unit to TS35 DIN rails.

Technical Specifications

Parameter	Specification
Module Width	105 mm
Module Height	90 mm
Module Depth	75 mm
Unit Weight	0.38 kg
Input Channels	8 (24V DC sinking)
Terminal Block	1 x 12-position (16 AWG)
Component Total	128 discrete parts
Input Voltage Range	19.2–30V DC
Input Current	6 mA per channel (typical)
On-State Threshold	>15V DC
Off-State Threshold	<5V DC
Response Time	3 ms (on/off)
Input Isolation	1500V (optocoupler)
Internal Energy Storage	330 µF capacitor bank
Operating Temperature	0°C to +55°C

Internal Design and Energy Storage

The B351 contains exactly 128 discrete components onboard. A 330 microfarad capacitor bank filters the internal logic supply voltage. Eight optocouplers provide complete isolation for every input channel. Each optocoupler withstands 1500 volts between field and logic sides. A shift register chip serializes the input data for backplane transmission. The module also includes LED drivers for the 8 status indicators.

Operational Performance

This input module connects directly to pushbuttons, limit switches, and proximity sensors. It accepts input voltages from 19.2 to 30 volts DC. Moreover, the module filters electrical noise with built-in debounce circuitry. You can mix 24V DC sinking sensors from different manufacturers without issues. The unit reports input state changes to the processor every scan cycle. Eight red LEDs show real-time input status across the front panel. Consequently, you achieve reliable signal acquisition for compact automation systems. Schneider designed this module for small-scale control applications. Its conformal coating protects against humidity and light contamination.

In summary, the B351 delivers dependable digital input functionality. Use this module for factory automation or conveyor systems. It provides 8 input points in a compact single-slot design. Order this input module for your Schneider automation system.