Siemens SIMATIC S7-300 6ES7326-1BK01-0AB0 F-Digital Input Module

Functional Overview

The Siemens 6ES7326-1BK01-0AB0 belongs to the SIMATIC S7-300 “Fail-Safe” series, specifically designed for safety-instrumented systems (SIS). This module acts as a bridge between safety-critical field sensors and an F-CPU (Fail-Safe Central Processing Unit). It actively monitors discrete signals from emergency stop buttons, light curtains, and safety switches to ensure the highest level of protection for personnel and machinery. By utilizing internal self-tests and redundant signal processing, the unit detects faults such as short circuits or wire breaks before they can compromise system safety.

Safety Certification and Performance

This module satisfies the most stringent international safety standards, making it suitable for high-risk industrial environments. It provides reliable operation through the following safety ratings:

• Safety Integrity Level: Capable of achieving SIL 3 according to IEC 61508.
• Performance Level: Rated up to PL e according to ISO 13849-1.
• Architecture: Features 24 digital inputs that can be configured for single-channel (SIL 2) or dual-channel (SIL 3) evaluation.
• Safety Protocol: Communicates via the PROFIsafe profile over PROFIBUS DP or PROFINET.

Diagnostics and Fault Detection

To maintain continuous safety, the 6ES7326-1BK01-0AB0 performs active diagnostic functions on every channel. It simplifies maintenance by providing granular feedback on the system’s state:

• Internal Monitoring: The module continuously checks its own internal electronic components and firmware integrity.
• External Monitoring: It actively detects external discrepancies such as cross-circuits, short-circuits to L+, or short-circuits to M.
• Status LEDs: Features a comprehensive array of LEDs, including a red “SF” (System Fault) light for hardware errors and a “SAFE” indicator to confirm fail-safe operation.
• Discrepancy Time: Allows users to configure the time window for dual-channel signals to reach the same state, preventing false trips during normal mechanical switching.

Integration and Configuration

Engineered for the S7-300 backplane, this module integrates seamlessly with the STEP 7 or TIA Portal engineering environments. It manages field connectivity through:

• Sensor Power Supply: Provides two integrated short-circuit proof power supplies for the connected safety sensors.
• Address Assignment: Uses a DIP switch located on the side of the module to set the unique F-destination address.
• Wiring Requirements: Requires a standard 40-pin front connector, allowing for organized termination of up to 24 safety inputs.

Technical Specifications

• Number of Inputs: 24 Digital F-Inputs
• Rated Voltage: 24 V DC
• Input Current: Typically 7 mA at 24V
• Isolation: Tested at 500 V DC between channels and the backplane bus
• Power Loss: Approximately 10 W during peak operation
• Dimensions: 80 mm (W) x 125 mm (H) x 120 mm (D)
• Net Weight: 442 g