Pilz PSS SB 3006 CN-A Compact Safety System

The Pilz PSS SB 3006 CN-A is a compact programmable safety system designed to monitor and control safety-related functions in industrial machinery and process automation. This safety controller belongs to the PSS SB series and provides a flexible, configurable solution for implementing safety logic such as emergency stop monitoring, safety gate interlocking, light curtain evaluation, and two-hand control systems. The PSS SB 3006 CN-A is certified according to EN ISO 13849-1 up to Performance Level PL e and EN IEC 62061 up to Safety Integrity Level SIL CL 3, making it suitable for a wide range of safety applications where the highest risk reduction is required.

System Architecture and Safe Logic

The PSS SB 3006 CN-A integrates a modular safety bus system that allows decentralized arrangement of input and output modules. The core unit houses the safe logic processor which executes the user-programmed safety function block diagram. The controller supports up to six expansion modules, enabling scalability for small to medium-sized safety networks. Cross communication between safety controllers is supported via the safety bus, allowing distributed safety tasks to coordinate across multiple machine zones. This architecture is particularly suited for flexible manufacturing cells and packaging machinery where safety devices are physically distributed but must interact coherently. The safe logic includes certified function blocks for muting, bypass, and time-delayed outputs, reducing the need for external safety relays.

Inputs and Outputs Configuration

The base unit provides a fixed number of safe inputs and outputs. The inputs are designed to connect all common safety sensors including mechanical switches, magnetic switches, OSSD outputs from light curtains, and emergency stop pushbuttons with dual-channel cross-fault monitoring. Each safe input is capable of detecting short circuits across channels, ensuring that a single fault does not lead to loss of safety function. The safe outputs are equipped with cross-circuit detection and can directly drive contactors or signalling devices up to rated current values. Outputs are protected against overcurrent and short circuits. The CN-A variant includes additional features such as expanded diagnostic memory and improved EMC immunity for use in electrically noisy industrial environments.

Programming and Configuration Software

Configuration of the PSS SB 3006 CN-A is performed using the Pilz PASconfig software, a graphical programming environment specifically designed for safety controllers. The software uses function block diagram (FBD) and ladder diagram (LD) editors, pre-validated safety function blocks, and an integrated verification tool to check for compliance with safety standards. Programs can be simulated offline before downloading to the device via a standard USB or Ethernet connection. The software also includes password protection for program security and access level management. A multilingual interface allows global engineering teams to collaborate on safety projects. The PASconfig software automatically calculates the achieved safety integrity level Performance Level and SIL for each configured safety chain, reporting potential weaknesses before commissioning.

Diagnostics and Maintenance Features

Diagnostic capabilities are built into the PSS SB 3006 CN-A to assist maintenance personnel in identifying the root cause of safety system stoppages. The controller logs safety events with timestamps, records channel-level input status changes, and provides visual indication through LEDs on the front panel. Detailed diagnostics can be read out via the configuration interface either locally with a laptop or remotely via a network connection if the system is integrated into the plant automation network. This reduces machine downtime significantly. The system also supports partial operation or muting sequences where specific safety functions can be temporarily suspended for maintenance access under controlled conditions, with all such overrides being logged and time-limited to enforce safe practices.