Product Description:

The X20SI4100 is a safety-oriented slice from B & R Automation in the X20 Fieldbus Input Output Modules series. In a distributed control system, it accepts emergency-stop buttons, guard-switch contacts, or light-curtain outputs and forwards their status through the backplane to a safety controller. Its purpose is to deliver deterministic signal acquisition so that machinery enters a safe-off state whenever a monitored circuit changes. The housing matches other X20 slices, enabling mixed installation without extra panel depth.

The module offers 4 safe digital inputs (Type A) that monitor potential-free contacts up to category 4, ensuring each channel is independently evaluated before the safety CPU accepts it. For devices that require a check pulse to validate wiring integrity, the unit provides 4 pulse outputs, each sourcing a test signal at 24 VDC. These test pulses are phase-shifted so adjacent input channels never receive the same edge simultaneously, reducing the chance of fault masking. Logic and diagnostic circuitry inside the slice draw 1.25 W of internal I/O power, which is supplied through the X20 power jumper; this consumption must be included when sizing the station power feed.

As a Safe Digital Input Module, the slice itself imposes a base load of 0.32 W of I/O module power on the backplane, while external field devices receive no feed through the channel group because the dedicated sensor/actuator supply remains at 0.00 W. The enclosure stands 99 mm high and extends only 75 mm deep, allowing it to fit inside shallow control cabinets without fouling door clearances. These consistent dimensions across the X20 family simplify rail layout because unsafe and safe slices share identical footprints. When combined with low heat dissipation, the physical profile permits dense stacking so safety, standard I/O, motion, and communication modules can be placed in a single row.