What this module does in the ET 200SP rack
The Siemens 6ES7131-6BF60-0AA0 is a 1-byte digital input module for the ET 200SP distributed I/O system. It reads eight sourcing (PNP) signals from 2-wire sensors or switches at 24 VDC nominal, converting them to a byte on the backplane bus. Signal "1" threshold is -11 V to -30 V referenced to L+, drawing a typical 6 mA per channel. Signal "0" is 30 V to -5 V referenced to L+. That means the module expects a sourcing sensor to pull the input below L+ by at least 11 V to register a true state.
Base unit and wiring constraints
This module mounts only on BU type A0 base units. A 2-wire sensor connects directly; a 3-wire sensor needs the AUX terminals on the base unit; a 4-wire sensor requires external terminal blocks. The base unit handles automatic encoding of the module type to the backplane.
Diagnostics and firmware
Diagnostic alarm and group error are supported; channel status shows via a green LED per input. I&M data from I&M0 to I&M3 is available for asset tracking. Firmware version is V1.0 and field-updateable. No oversampling, no isochronous mode, no hardware interrupt, no pulse extension, no counter, no wire-break detection, and no short-circuit detection. Between-channel isolation is not provided — the module relies on the base unit's isolation.
Cable length: unshielded up to 200 m, shielded up to 1 000 m. Isolation tested at 707 V DC type test.